diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index f3d70bf..1916c11 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -108,7 +108,7 @@ jobs:
     runs-on: ubuntu-latest
     environment:
       name: pypi
-      url: https://pypi.org/p/simagentplg
+      url: https://pypi.org/p/ejagent-core
     permissions:
       id-token: write
     steps:
diff --git a/.gitignore b/.gitignore
index 903380e..a344195 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,4 +14,5 @@ my_skills
 
 .pytest_cache
 
-.simagentplg-sessions
\ No newline at end of file
+.ejagent-sessions
+.simagentplg-sessions
diff --git a/README.md b/README.md
index 002133b..279b886 100644
--- a/README.md
+++ b/README.md
@@ -1,11 +1,12 @@
-# SimAgentPlg
+# EJAgent Core
 
 [English](README.md) | [简体中文](README_zh-CN.md)
 
-SimAgentPlg is a lightweight core for building stateful, extensible agents on
-OpenAI-compatible model APIs. It provides the runtime mechanism—state,
-orchestration, context construction, tool dispatch, middleware, MCP, and
-skills—while derived agents own concrete tools such as shell, file editing,
+EJAgent Core is an OpenAI-first Agent Harness Core built around eight capability
+areas: execution, control, extensibility, safety, context management, durable
+history, branching, and observability. It provides the runtime mechanisms for
+state, orchestration, context construction, tool dispatch, middleware, MCP, and
+skills, while derived agents own concrete tools such as shell, file editing,
 Git, or explicit completion.
 
 Requires Python 3.12 or newer.
@@ -48,16 +49,28 @@ Derived agents should provide equivalent implementations when needed.
 ## Installation
 
 ```bash
-uv sync
+pip install ejagent-core
+# or, for a source checkout: uv sync
 ```
 
 MCP support is optional. Install its extra only when the agent uses MCP:
 
 ```bash
 uv sync --extra mcp
-# or: pip install "SimAgentPlg[mcp]"
+# or: pip install "ejagent-core[mcp]"
 ```
 
+Version 0.6.0 renames the PyPI distribution to `ejagent-core` and the Python
+import package to `ejagent`:
+
+```python
+from ejagent import BaseAgent
+```
+
+The former `simagentplg` import is not retained as a compatibility alias.
+Existing JSONL Sessions remain readable; legacy internal message metadata is
+filtered from provider requests during restoration.
+
 ## Configuration
 
 Copy `.env.example` to `.env` and provide model credentials:
@@ -75,7 +88,7 @@ LLM_INCLUDE_USAGE=true
 Configuration can also be supplied directly:
 
 ```python
-from simagentplg import ModelConfig
+from ejagent import ModelConfig
 
 config = ModelConfig(
     model="deepseek-v4-flash",
@@ -95,7 +108,7 @@ provider-neutral stream events and the normalized `AssistantMessage` contract.
 Conversation history is preserved across calls:
 
 ```python
-from simagentplg import BaseAgent, ModelConfig, OpenAIModelAdapter
+from ejagent import BaseAgent, ModelConfig, OpenAIModelAdapter
 
 agent = BaseAgent(
     OpenAIModelAdapter(ModelConfig.from_env()),
@@ -246,7 +259,7 @@ next Provider request. It is deliberately separate from read-only Event Sinks
 and Tool Middleware:
 
 ```python
-from simagentplg import BehaviorDecision
+from ejagent import BehaviorDecision
 
 
 class StopAfterFirstToolTurn:
@@ -282,7 +295,7 @@ must explicitly declare a tool `READ_ONLY`, and the Runtime Policy must enable
 parallel calls:
 
 ```python
-from simagentplg import (
+from ejagent import (
     MethodToolHandler,
     RuntimePolicy,
     ToolDefinition,
@@ -337,7 +350,7 @@ the handler and its middleware, not an automatic side-effect inference.
 text and provisional reasoning are observed through typed Delta events:
 
 ```python
-from simagentplg import AssistantThinkingDelta, AssistantTextDelta
+from ejagent import AssistantThinkingDelta, AssistantTextDelta
 
 
 class ConsoleSink:
@@ -383,7 +396,7 @@ optional `CompactionPolicy` to assess the complete provider request before each
 model call:
 
 ```python
-from simagentplg import CompactionPolicy, ContextBudget
+from ejagent import CompactionPolicy, ContextBudget
 
 context_policy = CompactionPolicy(
     ContextBudget(
@@ -417,7 +430,7 @@ Automatic behavior is opt-in and reuses the same `CompactionPolicy` and
 `Compactor`:
 
 ```python
-from simagentplg import AutoCompactionPolicy
+from ejagent import AutoCompactionPolicy
 
 agent = BaseAgent(
     model,
@@ -494,7 +507,7 @@ or prompt.
 record for each accepted lifecycle mutation:
 
 ```python
-from simagentplg import JsonlSessionStorage, SessionRecorder
+from ejagent import JsonlSessionStorage, SessionRecorder
 
 storage = JsonlSessionStorage("./sessions")
 recorder = SessionRecorder(session_id="project-42", storage=storage)
@@ -568,7 +581,7 @@ semantics or provide another `SessionTreeStorage` backend.
 Tool availability and completion policy are independent:
 
 ```python
-from simagentplg import RuntimePolicy
+from ejagent import RuntimePolicy
 
 policy = RuntimePolicy(
     max_steps=20,
@@ -607,7 +620,7 @@ an async `do_add()` method:
 from collections.abc import Mapping
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     CancellationToken,
     MethodToolHandler,
     StepOutcome,
@@ -677,7 +690,7 @@ Long-running tools can optionally accept a scoped `progress` reporter. Existing
 `do_*` methods that do not declare this keyword remain compatible:
 
 ```python
-from simagentplg import ToolProgressReporter, ToolProgressUpdate
+from ejagent import ToolProgressReporter, ToolProgressUpdate
 
 
 async def do_index(
@@ -707,7 +720,7 @@ and are ignored after `ToolCompleted`. They never change `StepOutcome` or
 Tool payload and runtime control are separate:
 
 ```python
-from simagentplg import StepOutcome, ToolControl
+from ejagent import StepOutcome, ToolControl
 
 StepOutcome(data)  # continue the provider-tool loop
 StepOutcome(data, control=ToolControl.COMPLETE)
@@ -725,7 +738,7 @@ protocol.
 `ToolMiddleware` is the single interception chain around tool execution:
 
 ```python
-from simagentplg import ToolMiddleware
+from ejagent import ToolMiddleware
 
 
 class AuditMiddleware(ToolMiddleware):
@@ -741,7 +754,7 @@ same chain. It does not add a second policy path or a special `BaseAgent`
 parameter:
 
 ```python
-from simagentplg import (
+from ejagent import (
     RuleBasedToolPolicy,
     ToolApprovalDecision,
     ToolEffect,
@@ -803,7 +816,7 @@ invalid model arguments never consume policy limits, request approval, or
 reach a handler:
 
 ```python
-from simagentplg import (
+from ejagent import (
     ToolPolicyMiddleware,
     ToolSchemaValidationMiddleware,
 )
@@ -851,7 +864,7 @@ remains the distinct terminal `ToolControl.REJECT` path.
 MCP uses the same handler contract:
 
 ```python
-from simagentplg import (
+from ejagent import (
     BaseAgent,
     McpToolHandler,
     ModelConfig,
@@ -876,7 +889,7 @@ Skills are prompt and resource extensions independent of handler tools:
 ```python
 from pathlib import Path
 
-from simagentplg import BaseAgent, ModelConfig, OpenAIModelAdapter
+from ejagent import BaseAgent, ModelConfig, OpenAIModelAdapter
 
 agent = BaseAgent(
     OpenAIModelAdapter(ModelConfig.from_env()),
@@ -903,7 +916,7 @@ examples/skills/
 
 ## Core boundary
 
-SimAgentPlg core owns mechanisms:
+EJAgent Core owns mechanisms:
 
 ```text
 Orchestration + State + Context + Runtime Policy + Run Result
@@ -975,19 +988,22 @@ environment and PyPI publisher, merge the release commit into `main`, then push
 a version-matching tag:
 
 ```text
-PyPI project: SimAgentPlg
+PyPI project: ejagent-core
 GitHub owner: jyh20030112
-Repository: SimAgentPlg
+Repository: SimAgentPlg (rename separately)
 Workflow: release.yml
 Environment: pypi
 ```
 
+Because `ejagent-core` is a new PyPI project name, configure its Trusted
+Publisher before creating the `v0.6.0` release tag.
+
 Protect the GitHub `pypi` environment with required reviewers and restrict
 creation of `v*` tags to maintainers. Then publish with:
 
 ```bash
-git tag v0.5.0
-git push origin v0.5.0
+git tag v0.6.0
+git push origin v0.6.0
 ```
 
 The workflow rejects tags whose commit is not on `main` or whose value does not
diff --git a/README_zh-CN.md b/README_zh-CN.md
index 95f8005..e88c4d5 100644
--- a/README_zh-CN.md
+++ b/README_zh-CN.md
@@ -1,11 +1,11 @@
-# SimAgentPlg
+# EJAgent Core
 
 [English](README.md) | [简体中文](README_zh-CN.md)
 
-SimAgentPlg 是一个用于构建有状态、可扩展 Agent 的轻量级 Core，面向
-OpenAI-compatible 模型 API。Core 提供状态、编排、上下文、工具调度、
-Middleware、MCP 和 Skill 等运行机制；Shell、文件编辑、Git、审批界面和完成工具
-由具体派生 Agent 自行实现。
+EJAgent Core 是一个 OpenAI-first Agent Harness Core，围绕八个核心维度构建：
+执行内核、运行控制、可组合扩展、安全边界、上下文管理、持久历史、分支演化与
+可观测性。Core 提供状态、编排、上下文、工具调度、Middleware、MCP 和 Skill 等
+运行机制；Shell、文件编辑、Git、审批界面和完成工具由具体派生 Agent 自行实现。
 
 需要 Python 3.12 或更高版本。
 
@@ -45,16 +45,27 @@ CodeAgent 等派生 Agent。
 ## 安装
 
 ```bash
-uv sync
+pip install ejagent-core
+# 或在源码仓库中执行：uv sync
 ```
 
 MCP 支持是可选能力。只有使用 MCP 的 Agent 才需要安装额外依赖：
 
 ```bash
 uv sync --extra mcp
-# 或：pip install "SimAgentPlg[mcp]"
+# 或：pip install "ejagent-core[mcp]"
 ```
 
+0.6.0 将 PyPI Distribution 改名为 `ejagent-core`，Python Import Package 改为
+`ejagent`：
+
+```python
+from ejagent import BaseAgent
+```
+
+旧的 `simagentplg` Import 不再作为兼容别名保留。已有 JSONL Session 仍可读取；
+Restore 时会继续从 Provider 请求中剥离旧版内部消息元数据。
+
 ## 配置
 
 复制 `.env.example` 为 `.env` 并填写模型配置：
@@ -71,7 +82,7 @@ LLM_INCLUDE_USAGE=true
 `ModelConfig` 属于 `OpenAIModelAdapter`，不再属于 `BaseAgent`。也可以直接构造：
 
 ```python
-from simagentplg import ModelConfig
+from ejagent import ModelConfig
 
 config = ModelConfig(
     model="deepseek-v4-flash",
@@ -89,7 +100,7 @@ Client 的创建、响应归一化以及可选的启动/关闭资源；`BaseAgen
 多次调用之间会保留对话历史：
 
 ```python
-from simagentplg import BaseAgent, ModelConfig, OpenAIModelAdapter
+from ejagent import BaseAgent, ModelConfig, OpenAIModelAdapter
 
 agent = BaseAgent(
     OpenAIModelAdapter(ModelConfig.from_env()),
@@ -189,7 +200,7 @@ Continue 分配新的 `run_id`、发布 `AgentContinued`，并通过 `SessionRun
 `BehaviorHook.after_turn()` 决定一个非终态完整 Turn 是否允许进入下一次 Provider 请求：
 
 ```python
-from simagentplg import BehaviorDecision
+from ejagent import BehaviorDecision
 
 
 class StopAfterFirstToolTurn:
@@ -216,7 +227,7 @@ agent = BaseAgent(
 `ToolEffect.READ_ONLY`，Runtime Policy 也必须允许并行：
 
 ```python
-from simagentplg import (
+from ejagent import (
     MethodToolHandler,
     RuntimePolicy,
     ToolDefinition,
@@ -273,7 +284,7 @@ Context Window 容量和累计 Run 消耗是两个独立概念。可以为 Agent
 `CompactionPolicy`，在每次模型请求前评估完整 Provider 上下文：
 
 ```python
-from simagentplg import CompactionPolicy, ContextBudget
+from ejagent import CompactionPolicy, ContextBudget
 
 context_policy = CompactionPolicy(
     ContextBudget(
@@ -305,7 +316,7 @@ User/Assistant/Tool Turn，以及需要原文保留的最近 Turn。Tool Call 
 自动行为默认关闭；启用时复用同一个 `CompactionPolicy` 和 `Compactor`：
 
 ```python
-from simagentplg import AutoCompactionPolicy
+from ejagent import AutoCompactionPolicy
 
 agent = BaseAgent(
     model,
@@ -372,7 +383,7 @@ Token metadata，最后原子替换成“受保护消息 + Summary + 最近 Turn
 版本化语义 Record：
 
 ```python
-from simagentplg import JsonlSessionStorage, SessionRecorder
+from ejagent import JsonlSessionStorage, SessionRecorder
 
 storage = JsonlSessionStorage("./sessions")
 recorder = SessionRecorder(session_id="project-42", storage=storage)
@@ -434,7 +445,7 @@ Revision 或静默覆盖 Branch Head；过期 Head 返回 `SessionConflictError`
 工具是否存在和任务是否必须显式完成已经解耦：
 
 ```python
-from simagentplg import RuntimePolicy
+from ejagent import RuntimePolicy
 
 policy = RuntimePolicy(
     max_steps=20,
@@ -472,7 +483,7 @@ policy = RuntimePolicy(require_explicit_finish=True)
 from collections.abc import Mapping
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     MethodToolHandler,
     StepOutcome,
     ToolDefinition,
@@ -533,7 +544,7 @@ MethodToolHandler((OPENAI_TOOL_DICTIONARY,))
 现有 `do_*` 方法仍然兼容：
 
 ```python
-from simagentplg import ToolProgressReporter, ToolProgressUpdate
+from ejagent import ToolProgressReporter, ToolProgressUpdate
 
 
 async def do_index(
@@ -562,7 +573,7 @@ Progress 保持顺序，在取消或 `ToolCompleted` 后停止接收；它不会
 工具结果数据与运行控制已经分离：
 
 ```python
-from simagentplg import StepOutcome, ToolControl
+from ejagent import StepOutcome, ToolControl
 
 StepOutcome(data)  # 继续模型—工具循环
 StepOutcome(data, control=ToolControl.COMPLETE)
@@ -577,7 +588,7 @@ StepOutcome(data, control=ToolControl.CANCEL)
 `ToolMiddleware` 是工具执行外围唯一的拦截链：
 
 ```python
-from simagentplg import ToolMiddleware
+from ejagent import ToolMiddleware
 
 
 class AuditMiddleware(ToolMiddleware):
@@ -592,7 +603,7 @@ class AuditMiddleware(ToolMiddleware):
 Policy 通道，也不会给 `BaseAgent` 增加特殊参数：
 
 ```python
-from simagentplg import (
+from ejagent import (
     RuleBasedToolPolicy,
     ToolApprovalDecision,
     ToolEffect,
@@ -651,7 +662,7 @@ Core 只提供策略和审批协议，不提供审批 UI，也不内置 Shell、
 Policy 限额、请求审批或到达 Handler：
 
 ```python
-from simagentplg import (
+from ejagent import (
     ToolPolicyMiddleware,
     ToolSchemaValidationMiddleware,
 )
@@ -697,7 +708,7 @@ Schema 时则返回普通、非终态 Tool Result：
 MCP 使用相同的 Handler 协议：
 
 ```python
-from simagentplg import (
+from ejagent import (
     BaseAgent,
     McpToolHandler,
     ModelConfig,
@@ -721,7 +732,7 @@ Skill 是独立于 Handler 工具的提示词和资源扩展：
 ```python
 from pathlib import Path
 
-from simagentplg import BaseAgent, ModelConfig, OpenAIModelAdapter
+from ejagent import BaseAgent, ModelConfig, OpenAIModelAdapter
 
 agent = BaseAgent(
     OpenAIModelAdapter(ModelConfig.from_env()),
@@ -746,7 +757,7 @@ examples/skills/
 
 ## Core 边界
 
-SimAgentPlg Core 负责机制：
+EJAgent Core 负责机制：
 
 ```text
 Orchestration + State + Context + Runtime Policy + Run Result
@@ -806,19 +817,22 @@ PyPI 发布由 `.github/workflows/release.yml` 和 Trusted Publishing 完成，G
 合并到 `main`，再推送与项目版本一致的 Tag：
 
 ```text
-PyPI 项目：SimAgentPlg
+PyPI 项目：ejagent-core
 GitHub Owner：jyh20030112
-Repository：SimAgentPlg
+Repository：SimAgentPlg（单独执行远程改名）
 Workflow：release.yml
 Environment：pypi
 ```
 
+`ejagent-core` 是新的 PyPI 项目名，因此创建 `v0.6.0` Release Tag 前，需要先为它
+配置 Trusted Publisher。
+
 建议为 GitHub `pypi` Environment 配置 Required Reviewer，并限制只有 Maintainer 可以
 创建 `v*` Tag。然后执行：
 
 ```bash
-git tag v0.5.0
-git push origin v0.5.0
+git tag v0.6.0
+git push origin v0.6.0
 ```
 
 工作流会拒绝不在 `main` 上或与 `project.version` 不一致的 Tag，重新执行完整质量矩阵，
diff --git a/benchmarks/session_journal.py b/benchmarks/session_journal.py
index cfbf5b0..5bb9835 100644
--- a/benchmarks/session_journal.py
+++ b/benchmarks/session_journal.py
@@ -10,7 +10,7 @@
 from pathlib import Path
 from typing import Any
 
-from simagentplg import AgentSession, JsonlSessionStorage
+from ejagent import AgentSession, JsonlSessionStorage
 
 
 def journal_size(directory: str) -> int:
diff --git a/docs/pi-harness-gap-analysis.md b/docs/pi-harness-gap-analysis.md
index 9bb8deb..610cf3b 100644
--- a/docs/pi-harness-gap-analysis.md
+++ b/docs/pi-harness-gap-analysis.md
@@ -1,16 +1,16 @@
-# SimAgentPlg 与 Pi Agent Harness 能力对照
+# EJAgent Core 与 Pi Agent Harness 能力对照
 
 > 更新日期：2026-07-22
 >
-> SimAgentPlg 基线：`4864804` 后的 Core 能力工作树，项目版本 `0.5.0`
+> EJAgent Core 基线：`58d28f1` 后的 0.6.0 Rename 工作树
 >
 > Pi 子模块基线：`f4e9ca74`
 >
-> 对照范围：`pi/packages/agent`、`pi/packages/coding-agent` 与 SimAgentPlg Core
+> 对照范围：`pi/packages/agent`、`pi/packages/coding-agent` 与 EJAgent Core
 
 ## 1. 当前结论
 
-SimAgentPlg 已经不只是 Agent Loop。当前实现覆盖了通用 Agent Core 的主要执行机制：
+EJAgent Core 已经不只是 Agent Loop。当前实现覆盖了通用 Agent Core 的主要执行机制：
 
 - Provider-neutral 模型边界和 OpenAI-compatible Adapter
 - 模型—工具循环、结构化终止结果与 Runtime Policy
@@ -358,7 +358,7 @@ CD 属于交付能力，不改变 Core Runtime 语义。
 
 ## 4. 与 Pi 的能力矩阵
 
-| Harness 能力 | Pi 当前实现 | SimAgentPlg 当前实现 | 结论 |
+| Harness 能力 | Pi 当前实现 | EJAgent Core 当前实现 | 结论 |
 |---|---|---|---|
 | Agent Loop | `agentLoop` / `Agent` | `AgentOrchestrator` / `BaseAgent` | 已对齐核心能力 |
 | 结构化终止 | Assistant stop reason 为主 | `AgentRunResult` + `StopReason` | Sim 更显式 |
@@ -399,7 +399,7 @@ CD 属于交付能力，不改变 Core Runtime 语义。
 ### 5.1 只读 Event 与行为型 Hook
 
 Pi 的 Agent 和 Coding Agent 允许 Hook 阻止 Tool、改写结果、停止 Turn、注入资源或修改
-Context。SimAgentPlg 当前坚持：
+Context。EJAgent Core 当前坚持：
 
 - `AgentEventSink` 只观察，不修改行为。
 - Tool 行为改写只通过 `ToolMiddleware`。
@@ -417,7 +417,7 @@ Pi 当前同时存在 Harness Session Repo 和 Coding Agent Session Manager：
 - Coding Agent 支持 Compaction、Branch Summary、Custom Entry、Label、Model Change 等类型。
 - Repo Fork 可以把选定 Entry 路径复制到新的 JSONL Session，并记录 Parent Session。
 
-SimAgentPlg 使用一个 Session 一个 JSONL 文件，所有 Branch 共享祖先 Record：
+EJAgent Core 使用一个 Session 一个 JSONL 文件，所有 Branch 共享祖先 Record：
 
 ```text
 main:       r1 → r2 → r3 → r4
@@ -429,7 +429,7 @@ main:       r1 → r2 → r3 → r4
 
 ### 5.3 Retry 与外部副作用
 
-SimAgentPlg 不从 `ToolCompleted` 中间恢复，也不自动执行 Retry：
+EJAgent Core 不从 `ToolCompleted` 中间恢复，也不自动执行 Retry：
 
 1. 找到目标 `RUN_STARTED`。
 2. 回到该 Run 之前的完成状态。
@@ -441,13 +441,13 @@ SimAgentPlg 不从 `ToolCompleted` 中间恢复，也不自动执行 Retry：
 ### 5.4 Compaction 边界
 
 Pi Coding Agent 支持更丰富的 Branch Summary、Extension Compaction 和 mid-turn 相关语义。
-SimAgentPlg 当前只在完整 User Turn 边界切分，并让应用拥有 Summary Prompt。它更适合作为
+EJAgent Core 当前只在完整 User Turn 边界切分，并让应用拥有 Summary Prompt。它更适合作为
 通用 Core，但在超大单 Turn 或复杂分支摘要方面能力较弱。
 
 ### 5.5 Tool 执行顺序
 
 Pi 当前默认并行执行允许并行的 Tool Call，同时保证最终 Tool Result 按 Assistant 源顺序
-写入 transcript。SimAgentPlg 采用更保守的双重 opt-in：Handler 必须声明 `READ_ONLY`，Agent
+写入 transcript。EJAgent Core 采用更保守的双重 opt-in：Handler 必须声明 `READ_ONLY`，Agent
 还必须开启并行策略。连续只读调用并发运行，但 `ToolCompleted` 与 Tool Message 在批次完成后
 按源顺序提交；副作用工具不会与相邻只读批次重叠。
 
diff --git a/examples/01_stateful_chat.py b/examples/01_stateful_chat.py
index da81a38..c854ca1 100644
--- a/examples/01_stateful_chat.py
+++ b/examples/01_stateful_chat.py
@@ -2,7 +2,7 @@
 
 import asyncio
 
-from simagentplg import BaseAgent, ModelConfig, OpenAIModelAdapter
+from ejagent import BaseAgent, ModelConfig, OpenAIModelAdapter
 
 
 async def main() -> None:
diff --git a/examples/02_custom_tool.py b/examples/02_custom_tool.py
index 6d5900f..3afc6c9 100644
--- a/examples/02_custom_tool.py
+++ b/examples/02_custom_tool.py
@@ -4,7 +4,7 @@
 from collections.abc import Mapping
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     BaseAgent,
     CancellationToken,
     MethodToolHandler,
diff --git a/examples/04_mcp_tools.py b/examples/04_mcp_tools.py
index 207fe58..d24e9cd 100644
--- a/examples/04_mcp_tools.py
+++ b/examples/04_mcp_tools.py
@@ -3,7 +3,7 @@
 import asyncio
 from pathlib import Path
 
-from simagentplg import (
+from ejagent import (
     BaseAgent,
     McpToolHandler,
     ModelConfig,
diff --git a/examples/06_skill.py b/examples/06_skill.py
index 0bcea4f..ceb400f 100644
--- a/examples/06_skill.py
+++ b/examples/06_skill.py
@@ -3,7 +3,7 @@
 import asyncio
 from pathlib import Path
 
-from simagentplg import BaseAgent, ModelConfig, OpenAIModelAdapter
+from ejagent import BaseAgent, ModelConfig, OpenAIModelAdapter
 
 SKILLS_DIR = Path(__file__).with_name("skills")
 
@@ -22,7 +22,7 @@ async def main() -> None:
     try:
         result = await agent.runtime(
             task=(
-                "$release_notes Write release notes for SimAgentPlg 0.2.4. Changes: "
+                "$release_notes Write release notes for EJAgent Core 0.2.4. Changes: "
                 "added an orchestrator, structured run results, and runtime "
                 "policy controls."
             )
diff --git a/examples/07_event_observers.py b/examples/07_event_observers.py
index 4d83212..1a9f2c2 100644
--- a/examples/07_event_observers.py
+++ b/examples/07_event_observers.py
@@ -3,7 +3,7 @@
 import asyncio
 from collections import Counter
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AgentEventKind,
     BaseAgent,
diff --git a/examples/08_session_resume.py b/examples/08_session_resume.py
index 01ff241..0597936 100644
--- a/examples/08_session_resume.py
+++ b/examples/08_session_resume.py
@@ -2,7 +2,7 @@
 
 import asyncio
 
-from simagentplg import (
+from ejagent import (
     BaseAgent,
     MemorySessionStorage,
     ModelConfig,
@@ -27,7 +27,7 @@ async def main() -> None:
     try:
         first = await first_agent.run(
             task=(
-                "Store this exact statement and reply only ACK: SimAgentPlg "
+                "Store this exact statement and reply only ACK: EJAgent Core "
                 "uses lifecycle events to build Sessions without coupling "
                 "persistence to the Agent Loop."
             )
@@ -52,7 +52,7 @@ async def main() -> None:
     resumed_agent.reset(saved.messages)
     try:
         resumed = await resumed_agent.run(
-            task="Repeat the exact stored SimAgentPlg statement."
+            task="Repeat the exact stored EJAgent Core statement."
         )
         print(f"resumed response: {resumed.output}")
     finally:
diff --git a/examples/09_runtime_control.py b/examples/09_runtime_control.py
index 83dd27e..353dc63 100644
--- a/examples/09_runtime_control.py
+++ b/examples/09_runtime_control.py
@@ -5,7 +5,7 @@
 from collections.abc import AsyncIterator
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     BaseAgent,
     CancellationToken,
diff --git a/examples/10_composed_harness.py b/examples/10_composed_harness.py
index 5d4eefa..cade140 100644
--- a/examples/10_composed_harness.py
+++ b/examples/10_composed_harness.py
@@ -4,7 +4,7 @@
 from collections.abc import Mapping
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     BaseAgent,
     CancellationToken,
@@ -26,7 +26,7 @@
     "type": "function",
     "function": {
         "name": "inspect_project",
-        "description": "Return current SimAgentPlg Harness metadata.",
+        "description": "Return current EJAgent Core Harness metadata.",
         "parameters": {"type": "object", "properties": {}},
     },
 }
@@ -62,7 +62,7 @@ async def do_inspect_project(
         self.inspected = True
         return StepOutcome(
             {
-                "agent_core": "SimAgentPlg",
+                "agent_core": "EJAgent Core",
                 "orchestrator": "AgentOrchestrator",
                 "events": "AgentEvent + CompositeAgentEventSink",
                 "session": "SessionRecorder + MemorySessionStorage",
diff --git a/examples/11_streaming_events.py b/examples/11_streaming_events.py
index 8c1d32b..c8dfad1 100644
--- a/examples/11_streaming_events.py
+++ b/examples/11_streaming_events.py
@@ -2,7 +2,7 @@
 
 import asyncio
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AgentFinished,
     AssistantTextDelta,
diff --git a/examples/12_tool_progress.py b/examples/12_tool_progress.py
index 1e43204..87edc3e 100644
--- a/examples/12_tool_progress.py
+++ b/examples/12_tool_progress.py
@@ -4,7 +4,7 @@
 from collections.abc import Mapping
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AgentFinished,
     BaseAgent,
diff --git a/examples/13_usage_budget.py b/examples/13_usage_budget.py
index 8f189d4..a111b23 100644
--- a/examples/13_usage_budget.py
+++ b/examples/13_usage_budget.py
@@ -5,7 +5,7 @@
 from collections.abc import Mapping
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AgentFinished,
     BaseAgent,
diff --git a/examples/14_context_pressure.py b/examples/14_context_pressure.py
index 043f09d..abce0d3 100644
--- a/examples/14_context_pressure.py
+++ b/examples/14_context_pressure.py
@@ -5,7 +5,7 @@
 from collections.abc import Mapping
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     BaseAgent,
     CancellationToken,
diff --git a/examples/15_explicit_compaction.py b/examples/15_explicit_compaction.py
index 079f27a..2353b40 100644
--- a/examples/15_explicit_compaction.py
+++ b/examples/15_explicit_compaction.py
@@ -4,7 +4,7 @@
 import json
 import os
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     BaseAgent,
     CompactionCompleted,
@@ -30,7 +30,7 @@ def build_compaction_context(request: CompactionRequest) -> ContextBuildResult:
         {
             key: value
             for key, value in message.items()
-            if key not in {"usage", "_simagentplg_summary"}
+            if key not in {"usage", "_ejagent_summary", "_simagentplg_summary"}
         }
         for message in request.preparation.messages_to_summarize
     ]
diff --git a/examples/16_durable_session.py b/examples/16_durable_session.py
index 426446f..4710667 100644
--- a/examples/16_durable_session.py
+++ b/examples/16_durable_session.py
@@ -5,7 +5,7 @@
 import os
 from pathlib import Path
 
-from simagentplg import (
+from ejagent import (
     BaseAgent,
     JsonlSessionStorage,
     ModelConfig,
@@ -77,7 +77,7 @@ async def main() -> None:
     parser.add_argument("command", choices=("record", "resume"))
     parser.add_argument(
         "--session-dir",
-        default=os.getenv("SIMAGENTPLG_SESSION_DIR", ".simagentplg-sessions"),
+        default=os.getenv("EJAGENT_SESSION_DIR", ".ejagent-sessions"),
     )
     args = parser.parse_args()
     storage = JsonlSessionStorage(Path(args.session_dir))
diff --git a/examples/17_session_tree.py b/examples/17_session_tree.py
index 84bbd8a..6c7ed59 100644
--- a/examples/17_session_tree.py
+++ b/examples/17_session_tree.py
@@ -5,7 +5,7 @@
 import os
 from pathlib import Path
 
-from simagentplg import JsonlSessionStorage
+from ejagent import JsonlSessionStorage
 
 
 async def main() -> None:
@@ -13,7 +13,7 @@ async def main() -> None:
     parser.add_argument("--session-id", default="durable-session-demo")
     parser.add_argument(
         "--session-dir",
-        default=os.getenv("SIMAGENTPLG_SESSION_DIR", ".simagentplg-sessions"),
+        default=os.getenv("EJAGENT_SESSION_DIR", ".ejagent-sessions"),
     )
     commands = parser.add_subparsers(dest="command", required=True)
     commands.add_parser("branches")
diff --git a/examples/README.md b/examples/README.md
index e53d716..780a070 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -1,4 +1,4 @@
-# SimAgentPlg Examples
+# EJAgent Core Examples
 
 All examples use the environment variables documented in the project README.
 Copy `.env.example` to `.env` and fill in credentials for an OpenAI-compatible
diff --git a/pyproject.toml b/pyproject.toml
index 5594aa3..09ff2bf 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [project]
-name = "SimAgentPlg"
-version = "0.5.0"
-description = "A lightweight stateful agent framework with ReAct reasoning, tool dispatch, and MCP integration"
+name = "ejagent-core"
+version = "0.6.0"
+description = "An OpenAI-first agent harness core for controlled, durable, and observable agent runtimes"
 readme = "README.md"
 license = {file = "LICENSE"}
 requires-python = ">=3.12"
@@ -36,7 +36,7 @@ requires = ["hatchling"]
 build-backend = "hatchling.build"
 
 [tool.hatch.build.targets.wheel]
-packages = ["src/simagentplg"]
+packages = ["src/ejagent"]
 
 [tool.hatch.build.targets.sdist]
 exclude = [
@@ -57,7 +57,7 @@ ignore = [
 
 [tool.mypy]
 python_version = "3.12"
-files = ["src/simagentplg"]
+files = ["src/ejagent"]
 check_untyped_defs = true
 disallow_untyped_defs = true
 no_implicit_optional = true
diff --git a/src/simagentplg/__init__.py b/src/ejagent/__init__.py
similarity index 87%
rename from src/simagentplg/__init__.py
rename to src/ejagent/__init__.py
index da6fd9e..13b08b1 100644
--- a/src/simagentplg/__init__.py
+++ b/src/ejagent/__init__.py
@@ -1,19 +1,19 @@
 """Composable stateful agents with tool handlers and MCP integration."""
 
-from simagentplg.agent.base import BaseAgent
-from simagentplg.agent.behavior import (
+from ejagent.agent.base import BaseAgent
+from ejagent.agent.behavior import (
     BehaviorAction,
     BehaviorDecision,
     BehaviorHook,
     BehaviorHookError,
     TurnSnapshot,
 )
-from simagentplg.agent.cancellation import (
+from ejagent.agent.cancellation import (
     AgentCancelledError,
     CancellationSource,
     CancellationToken,
 )
-from simagentplg.agent.compaction import (
+from ejagent.agent.compaction import (
     CompactionRequest,
     CompactionResult,
     CompactionRuntime,
@@ -23,8 +23,8 @@
     CompactorOutput,
     SummaryEntry,
 )
-from simagentplg.agent.context_builder import AgentContextBuilder, ContextBuildResult
-from simagentplg.agent.context_management import (
+from ejagent.agent.context_builder import AgentContextBuilder, ContextBuildResult
+from ejagent.agent.context_management import (
     AutoCompactionPolicy,
     CompactionDecision,
     CompactionDecisionReason,
@@ -38,7 +38,7 @@
     estimate_context_usage,
     prepare_compaction,
 )
-from simagentplg.agent.control import (
+from ejagent.agent.control import (
     ContinueRejectedError,
     ContinueRejectedReason,
     ControlInput,
@@ -52,7 +52,7 @@
     FollowUpHandle,
     FollowUpRejectedError,
 )
-from simagentplg.agent.events import (
+from ejagent.agent.events import (
     AgentContinued,
     AgentEvent,
     AgentEventKind,
@@ -77,28 +77,28 @@
     TurnCompleted,
     TurnStarted,
 )
-from simagentplg.agent.model_compactor import (
+from ejagent.agent.model_compactor import (
     CompactionContextBuilder,
     ModelCompactor,
 )
-from simagentplg.agent.orchestrator import AgentOrchestrator
-from simagentplg.agent.result import (
+from ejagent.agent.orchestrator import AgentOrchestrator
+from ejagent.agent.result import (
     AgentRunError,
     AgentRunResult,
     RunStatus,
     StopReason,
 )
-from simagentplg.agent.runtime_policy import RuntimePolicy
-from simagentplg.agent.state import AgentState, AgentStatus
-from simagentplg.agent.types import (
+from ejagent.agent.runtime_policy import RuntimePolicy
+from ejagent.agent.state import AgentState, AgentStatus
+from ejagent.agent.types import (
     StepOutcome,
     ToolCallResult,
     ToolControl,
     ToolProgressReporter,
     ToolProgressUpdate,
 )
-from simagentplg.agent.usage import RunUsage
-from simagentplg.handlers import (
+from ejagent.agent.usage import RunUsage
+from ejagent.handlers import (
     BaseHandler,
     McpToolHandler,
     MethodToolHandler,
@@ -107,7 +107,7 @@
     ToolEffect,
     UnknownToolError,
 )
-from simagentplg.middleware import (
+from ejagent.middleware import (
     Middleware,
     RuleBasedToolPolicy,
     ToolApprovalDecision,
@@ -127,9 +127,9 @@
     compose_tool_middlewares,
     format_tool_call_preview,
 )
-from simagentplg.plugins.mcp.mcp_manager import McpServerManager
-from simagentplg.plugins.skill.skill_manager import SkillManager
-from simagentplg.providers import (
+from ejagent.plugins.mcp.mcp_manager import McpServerManager
+from ejagent.plugins.skill.skill_manager import SkillManager
+from ejagent.providers import (
     AssistantMessage,
     ContextOverflowError,
     ModelAdapter,
@@ -147,7 +147,7 @@
     ModelUsage,
     OpenAIModelAdapter,
 )
-from simagentplg.session import (
+from ejagent.session import (
     DEFAULT_SESSION_BRANCH,
     SESSION_JOURNAL_SCHEMA_VERSION,
     SESSION_SCHEMA_VERSION,
diff --git a/src/simagentplg/agent/__init__.py b/src/ejagent/agent/__init__.py
similarity index 85%
rename from src/simagentplg/agent/__init__.py
rename to src/ejagent/agent/__init__.py
index 5681bc9..0b8de8f 100644
--- a/src/simagentplg/agent/__init__.py
+++ b/src/ejagent/agent/__init__.py
@@ -1,19 +1,19 @@
 """Agent runtime primitives."""
 
-from simagentplg.agent.base import BaseAgent
-from simagentplg.agent.behavior import (
+from ejagent.agent.base import BaseAgent
+from ejagent.agent.behavior import (
     BehaviorAction,
     BehaviorDecision,
     BehaviorHook,
     BehaviorHookError,
     TurnSnapshot,
 )
-from simagentplg.agent.cancellation import (
+from ejagent.agent.cancellation import (
     AgentCancelledError,
     CancellationSource,
     CancellationToken,
 )
-from simagentplg.agent.compaction import (
+from ejagent.agent.compaction import (
     CompactionRequest,
     CompactionResult,
     CompactionRuntime,
@@ -23,8 +23,8 @@
     CompactorOutput,
     SummaryEntry,
 )
-from simagentplg.agent.context_builder import AgentContextBuilder, ContextBuildResult
-from simagentplg.agent.context_management import (
+from ejagent.agent.context_builder import AgentContextBuilder, ContextBuildResult
+from ejagent.agent.context_management import (
     AutoCompactionPolicy,
     CompactionDecision,
     CompactionDecisionReason,
@@ -38,7 +38,7 @@
     estimate_context_usage,
     prepare_compaction,
 )
-from simagentplg.agent.control import (
+from ejagent.agent.control import (
     ContinueRejectedError,
     ContinueRejectedReason,
     ControlInput,
@@ -52,7 +52,7 @@
     FollowUpHandle,
     FollowUpRejectedError,
 )
-from simagentplg.agent.events import (
+from ejagent.agent.events import (
     AgentContinued,
     AgentEvent,
     AgentEventKind,
@@ -77,28 +77,28 @@
     TurnCompleted,
     TurnStarted,
 )
-from simagentplg.agent.model_compactor import (
+from ejagent.agent.model_compactor import (
     CompactionContextBuilder,
     ModelCompactor,
 )
-from simagentplg.agent.orchestrator import AgentOrchestrator
-from simagentplg.agent.result import (
+from ejagent.agent.orchestrator import AgentOrchestrator
+from ejagent.agent.result import (
     AgentRunError,
     AgentRunResult,
     RunStatus,
     StopReason,
 )
-from simagentplg.agent.runtime_policy import RuntimePolicy
-from simagentplg.agent.state import AgentState, AgentStatus
-from simagentplg.agent.types import (
+from ejagent.agent.runtime_policy import RuntimePolicy
+from ejagent.agent.state import AgentState, AgentStatus
+from ejagent.agent.types import (
     StepOutcome,
     ToolCallResult,
     ToolControl,
     ToolProgressReporter,
     ToolProgressUpdate,
 )
-from simagentplg.agent.usage import RunUsage
-from simagentplg.middleware import (
+from ejagent.agent.usage import RunUsage
+from ejagent.middleware import (
     Middleware,
     RuleBasedToolPolicy,
     ToolApprovalDecision,
diff --git a/src/simagentplg/agent/base.py b/src/ejagent/agent/base.py
similarity index 95%
rename from src/simagentplg/agent/base.py
rename to src/ejagent/agent/base.py
index c1549ea..1077302 100644
--- a/src/simagentplg/agent/base.py
+++ b/src/ejagent/agent/base.py
@@ -6,22 +6,22 @@
 from pathlib import Path
 from typing import TYPE_CHECKING, Any
 
-from simagentplg.agent.behavior import BehaviorHook
-from simagentplg.agent.cancellation import (
+from ejagent.agent.behavior import BehaviorHook
+from ejagent.agent.cancellation import (
     CancellationSource,
 )
-from simagentplg.agent.compaction import (
+from ejagent.agent.compaction import (
     CompactionResult,
     CompactionRuntime,
     Compactor,
 )
-from simagentplg.agent.context_builder import AgentContextBuilder
-from simagentplg.agent.context_management import (
+from ejagent.agent.context_builder import AgentContextBuilder
+from ejagent.agent.context_management import (
     AutoCompactionPolicy,
     CompactionPolicy,
     MessageTokenEstimator,
 )
-from simagentplg.agent.control import (
+from ejagent.agent.control import (
     ContinueRejectedError,
     ContinueRejectedReason,
     ControlInput,
@@ -34,25 +34,25 @@
     _FollowUpQueue,
     _SteeringQueue,
 )
-from simagentplg.agent.events import (
+from ejagent.agent.events import (
     AgentEventEmitter,
     AgentEventSink,
 )
-from simagentplg.agent.orchestrator import AgentOrchestrator
-from simagentplg.agent.result import AgentRunResult
-from simagentplg.agent.runtime_policy import RuntimePolicy
-from simagentplg.agent.state import AgentState
-from simagentplg.agent.tool_runtime import ToolRuntime
-from simagentplg.agent.types import StepOutcome
-from simagentplg.logger import get_logger
-from simagentplg.middleware import ToolMiddleware
-from simagentplg.plugins.skill.skill_manager import SkillManager
-from simagentplg.providers.base import ModelAdapter
+from ejagent.agent.orchestrator import AgentOrchestrator
+from ejagent.agent.result import AgentRunResult
+from ejagent.agent.runtime_policy import RuntimePolicy
+from ejagent.agent.state import AgentState
+from ejagent.agent.tool_runtime import ToolRuntime
+from ejagent.agent.types import StepOutcome
+from ejagent.logger import get_logger
+from ejagent.middleware import ToolMiddleware
+from ejagent.plugins.skill.skill_manager import SkillManager
+from ejagent.providers.base import ModelAdapter
 
 if TYPE_CHECKING:
-    from simagentplg.handlers.base import BaseHandler
-    from simagentplg.handlers.definition import ToolDefinition
-    from simagentplg.session.types import AgentSession
+    from ejagent.handlers.base import BaseHandler
+    from ejagent.handlers.definition import ToolDefinition
+    from ejagent.session.types import AgentSession
 
 DEFAULT_SYSTEM_PROMPT = "You are a helpful, concise assistant."
 
diff --git a/src/simagentplg/agent/behavior.py b/src/ejagent/agent/behavior.py
similarity index 94%
rename from src/simagentplg/agent/behavior.py
rename to src/ejagent/agent/behavior.py
index b3d3879..8a93342 100644
--- a/src/simagentplg/agent/behavior.py
+++ b/src/ejagent/agent/behavior.py
@@ -6,10 +6,10 @@
 from enum import StrEnum
 from typing import Protocol
 
-from simagentplg.agent.cancellation import CancellationToken
-from simagentplg.agent.types import AgentMessage
-from simagentplg.agent.usage import RunUsage
-from simagentplg.providers.base import AssistantMessage
+from ejagent.agent.cancellation import CancellationToken
+from ejagent.agent.types import AgentMessage
+from ejagent.agent.usage import RunUsage
+from ejagent.providers.base import AssistantMessage
 
 
 class BehaviorAction(StrEnum):
diff --git a/src/simagentplg/agent/cancellation.py b/src/ejagent/agent/cancellation.py
similarity index 100%
rename from src/simagentplg/agent/cancellation.py
rename to src/ejagent/agent/cancellation.py
diff --git a/src/simagentplg/agent/compaction.py b/src/ejagent/agent/compaction.py
similarity index 97%
rename from src/simagentplg/agent/compaction.py
rename to src/ejagent/agent/compaction.py
index fd0cf06..acfeec0 100644
--- a/src/simagentplg/agent/compaction.py
+++ b/src/ejagent/agent/compaction.py
@@ -8,20 +8,20 @@
 from typing import TYPE_CHECKING, Any, Protocol
 from uuid import uuid4
 
-from simagentplg.agent.cancellation import (
+from ejagent.agent.cancellation import (
     AgentCancelledError,
     CancellationToken,
 )
-from simagentplg.agent.context_management import (
+from ejagent.agent.context_management import (
     CompactionPolicy,
     CompactionPreparation,
     MessageTokenEstimator,
 )
-from simagentplg.agent.state import AgentState
-from simagentplg.agent.types import INTERNAL_METADATA_PREFIX, AgentMessage
+from ejagent.agent.state import AgentState
+from ejagent.agent.types import INTERNAL_METADATA_PREFIX, AgentMessage
 
 if TYPE_CHECKING:
-    from simagentplg.agent.events import AgentEventEmitter
+    from ejagent.agent.events import AgentEventEmitter
 
 
 SUMMARY_METADATA_KEY = f"{INTERNAL_METADATA_PREFIX}summary"
@@ -338,7 +338,7 @@ async def compact_in_active_run(
     ) -> CompactionResult:
         """Compact while reusing the caller's active Agent event run."""
 
-        from simagentplg.agent.events import (
+        from ejagent.agent.events import (
             CompactionCompleted,
             CompactionFailed,
             CompactionStarted,
diff --git a/src/simagentplg/agent/context_builder.py b/src/ejagent/agent/context_builder.py
similarity index 92%
rename from src/simagentplg/agent/context_builder.py
rename to src/ejagent/agent/context_builder.py
index 844edce..0a8fe60 100644
--- a/src/simagentplg/agent/context_builder.py
+++ b/src/ejagent/agent/context_builder.py
@@ -4,14 +4,14 @@
 from dataclasses import dataclass
 from typing import Any
 
-from simagentplg.agent.state import AgentState
-from simagentplg.agent.types import INTERNAL_METADATA_PREFIX, AgentMessage
-from simagentplg.handlers.definition import (
+from ejagent.agent.state import AgentState
+from ejagent.agent.types import AgentMessage, is_internal_metadata_key
+from ejagent.handlers.definition import (
     ToolDefinition,
     ToolDefinitionInput,
     normalize_tool_definitions,
 )
-from simagentplg.plugins.skill.skill_manager import SkillManager
+from ejagent.plugins.skill.skill_manager import SkillManager
 
 
 @dataclass(frozen=True, slots=True)
@@ -82,7 +82,7 @@ def _strip_internal_metadata(
             {
                 key: value
                 for key, value in message.items()
-                if key != "usage" and not key.startswith(INTERNAL_METADATA_PREFIX)
+                if key != "usage" and not is_internal_metadata_key(key)
             }
             for message in messages
         ]
diff --git a/src/simagentplg/agent/context_management.py b/src/ejagent/agent/context_management.py
similarity index 98%
rename from src/simagentplg/agent/context_management.py
rename to src/ejagent/agent/context_management.py
index 78e05dd..4e62ce9 100644
--- a/src/simagentplg/agent/context_management.py
+++ b/src/ejagent/agent/context_management.py
@@ -8,8 +8,8 @@
 from enum import StrEnum
 from typing import Any, Protocol
 
-from simagentplg.agent.types import INTERNAL_METADATA_PREFIX, AgentMessage
-from simagentplg.providers.base import ModelUsage
+from ejagent.agent.types import AgentMessage, is_internal_metadata_key
+from ejagent.providers.base import ModelUsage
 
 
 class ContextUsageSource(StrEnum):
@@ -79,7 +79,7 @@ def estimate_message(self, message: Mapping[str, Any]) -> int:
         visible = {
             key: value
             for key, value in message.items()
-            if key != "usage" and not key.startswith(INTERNAL_METADATA_PREFIX)
+            if key != "usage" and not is_internal_metadata_key(key)
         }
         return self.message_overhead_tokens + self._estimate_value(visible)
 
diff --git a/src/simagentplg/agent/control.py b/src/ejagent/agent/control.py
similarity index 98%
rename from src/simagentplg/agent/control.py
rename to src/ejagent/agent/control.py
index 67e66c1..45cae36 100644
--- a/src/simagentplg/agent/control.py
+++ b/src/ejagent/agent/control.py
@@ -7,8 +7,8 @@
 from enum import StrEnum
 from uuid import uuid4
 
-from simagentplg.agent.result import AgentRunResult, StopReason
-from simagentplg.agent.types import AgentMessage
+from ejagent.agent.result import AgentRunResult, StopReason
+from ejagent.agent.types import AgentMessage
 
 
 class ControlInputKind(StrEnum):
diff --git a/src/simagentplg/agent/events.py b/src/ejagent/agent/events.py
similarity index 96%
rename from src/simagentplg/agent/events.py
rename to src/ejagent/agent/events.py
index ea56ed8..4afac91 100644
--- a/src/simagentplg/agent/events.py
+++ b/src/ejagent/agent/events.py
@@ -7,19 +7,19 @@
 from typing import ClassVar, Protocol, TypeAlias
 from uuid import uuid4
 
-from simagentplg.agent.compaction import (
+from ejagent.agent.compaction import (
     CompactionRequest,
     CompactionResult,
     CompactionStatus,
 )
-from simagentplg.agent.context_management import (
+from ejagent.agent.context_management import (
     CompactionDecision,
     CompactionPreparation,
 )
-from simagentplg.agent.control import ControlInput, ControlInputKind
-from simagentplg.agent.result import AgentRunResult, StopReason
-from simagentplg.agent.types import ToolCallResult, ToolProgressUpdate
-from simagentplg.providers.base import (
+from ejagent.agent.control import ControlInput, ControlInputKind
+from ejagent.agent.result import AgentRunResult, StopReason
+from ejagent.agent.types import ToolCallResult, ToolProgressUpdate
+from ejagent.providers.base import (
     AssistantMessage,
     ModelToolCall,
     ModelUsage,
diff --git a/src/simagentplg/agent/model_compactor.py b/src/ejagent/agent/model_compactor.py
similarity index 89%
rename from src/simagentplg/agent/model_compactor.py
rename to src/ejagent/agent/model_compactor.py
index 54244eb..d8a2832 100644
--- a/src/simagentplg/agent/model_compactor.py
+++ b/src/ejagent/agent/model_compactor.py
@@ -2,13 +2,13 @@
 
 from typing import Protocol
 
-from simagentplg.agent.cancellation import CancellationToken
-from simagentplg.agent.compaction import (
+from ejagent.agent.cancellation import CancellationToken
+from ejagent.agent.compaction import (
     CompactionRequest,
     CompactorOutput,
 )
-from simagentplg.agent.context_builder import ContextBuildResult
-from simagentplg.providers.base import AssistantMessage, ModelAdapter
+from ejagent.agent.context_builder import ContextBuildResult
+from ejagent.providers.base import AssistantMessage, ModelAdapter
 
 
 class CompactionContextBuilder(Protocol):
diff --git a/src/simagentplg/agent/orchestrator.py b/src/ejagent/agent/orchestrator.py
similarity index 97%
rename from src/simagentplg/agent/orchestrator.py
rename to src/ejagent/agent/orchestrator.py
index c07408e..73d3fca 100644
--- a/src/simagentplg/agent/orchestrator.py
+++ b/src/ejagent/agent/orchestrator.py
@@ -5,41 +5,41 @@
 from contextlib import suppress
 from typing import Any, Protocol
 
-from simagentplg.agent.behavior import (
+from ejagent.agent.behavior import (
     BehaviorAction,
     BehaviorDecision,
     BehaviorHook,
     BehaviorHookError,
     TurnSnapshot,
 )
-from simagentplg.agent.cancellation import (
+from ejagent.agent.cancellation import (
     AgentCancelledError,
     CancellationSource,
     CancellationToken,
 )
-from simagentplg.agent.compaction import (
+from ejagent.agent.compaction import (
     CompactionRuntime,
     CompactionStatus,
     CompactionTrigger,
     Compactor,
 )
-from simagentplg.agent.context_builder import (
+from ejagent.agent.context_builder import (
     AgentContextBuilder,
     ContextBuildResult,
 )
-from simagentplg.agent.context_management import (
+from ejagent.agent.context_management import (
     AutoCompactionPolicy,
     CompactionPolicy,
     CompactionPreparation,
     MessageTokenEstimator,
     estimate_context_usage,
 )
-from simagentplg.agent.control import (
+from ejagent.agent.control import (
     ContinueRejectedError,
     _continue_history_rejection_reason,
     _SteeringQueue,
 )
-from simagentplg.agent.events import (
+from ejagent.agent.events import (
     AgentContinued,
     AgentEventEmitter,
     AgentFinished,
@@ -53,18 +53,18 @@
     TurnCompleted,
     TurnStarted,
 )
-from simagentplg.agent.result import AgentRunResult, RunStatus, StopReason
-from simagentplg.agent.runtime_policy import RuntimePolicy
-from simagentplg.agent.state import AgentState
-from simagentplg.agent.tool_runtime import (
+from ejagent.agent.result import AgentRunResult, RunStatus, StopReason
+from ejagent.agent.runtime_policy import RuntimePolicy
+from ejagent.agent.state import AgentState
+from ejagent.agent.tool_runtime import (
     RepeatedToolCallError,
     ToolRuntime,
 )
-from simagentplg.agent.types import ToolCallResult, ToolControl
-from simagentplg.agent.usage import UsageAccumulator
-from simagentplg.handlers.definition import ToolDefinition, ToolEffect
-from simagentplg.plugins.skill.skill_manager import SkillManager
-from simagentplg.providers.base import (
+from ejagent.agent.types import ToolCallResult, ToolControl
+from ejagent.agent.usage import UsageAccumulator
+from ejagent.handlers.definition import ToolDefinition, ToolEffect
+from ejagent.plugins.skill.skill_manager import SkillManager
+from ejagent.providers.base import (
     AssistantMessage,
     ContextOverflowError,
     ModelResponseCompleted,
diff --git a/src/simagentplg/agent/result.py b/src/ejagent/agent/result.py
similarity index 97%
rename from src/simagentplg/agent/result.py
rename to src/ejagent/agent/result.py
index 8d24c3b..dbf5d73 100644
--- a/src/simagentplg/agent/result.py
+++ b/src/ejagent/agent/result.py
@@ -3,7 +3,7 @@
 from dataclasses import dataclass, field
 from enum import StrEnum
 
-from simagentplg.agent.usage import RunUsage
+from ejagent.agent.usage import RunUsage
 
 
 class RunStatus(StrEnum):
diff --git a/src/simagentplg/agent/runtime_policy.py b/src/ejagent/agent/runtime_policy.py
similarity index 100%
rename from src/simagentplg/agent/runtime_policy.py
rename to src/ejagent/agent/runtime_policy.py
diff --git a/src/simagentplg/agent/state.py b/src/ejagent/agent/state.py
similarity index 97%
rename from src/simagentplg/agent/state.py
rename to src/ejagent/agent/state.py
index 31cab06..841e86e 100644
--- a/src/simagentplg/agent/state.py
+++ b/src/ejagent/agent/state.py
@@ -4,8 +4,8 @@
 from dataclasses import dataclass, field
 from enum import StrEnum
 
-from simagentplg.agent.result import AgentRunResult
-from simagentplg.agent.types import AgentMessage
+from ejagent.agent.result import AgentRunResult
+from ejagent.agent.types import AgentMessage
 
 
 class AgentStatus(StrEnum):
diff --git a/src/simagentplg/agent/tool_runtime.py b/src/ejagent/agent/tool_runtime.py
similarity index 97%
rename from src/simagentplg/agent/tool_runtime.py
rename to src/ejagent/agent/tool_runtime.py
index 0136cf5..9c50e3d 100644
--- a/src/simagentplg/agent/tool_runtime.py
+++ b/src/ejagent/agent/tool_runtime.py
@@ -4,34 +4,34 @@
 from collections.abc import Iterable, Mapping, Sequence
 from typing import Any
 
-from simagentplg.agent.cancellation import (
+from ejagent.agent.cancellation import (
     AgentCancelledError,
     CancellationSource,
     CancellationToken,
 )
-from simagentplg.agent.events import (
+from ejagent.agent.events import (
     AgentEventEmitter,
     ToolCompleted,
     ToolProgressed,
     ToolStarted,
 )
-from simagentplg.agent.state import AgentState
-from simagentplg.agent.types import (
+from ejagent.agent.state import AgentState
+from ejagent.agent.types import (
     StepOutcome,
     ToolCallResult,
     ToolControl,
     ToolProgressReporter,
     ToolProgressUpdate,
 )
-from simagentplg.handlers.base import BaseHandler
-from simagentplg.handlers.definition import ToolDefinition, ToolEffect
-from simagentplg.middleware import (
+from ejagent.handlers.base import BaseHandler
+from ejagent.handlers.definition import ToolDefinition, ToolEffect
+from ejagent.middleware import (
     ToolCallContext,
     ToolMiddleware,
     ToolNext,
     compose_tool_middlewares,
 )
-from simagentplg.providers.base import ModelToolCall
+from ejagent.providers.base import ModelToolCall
 
 
 class RepeatedToolCallError(RuntimeError):
diff --git a/src/simagentplg/agent/types.py b/src/ejagent/agent/types.py
similarity index 77%
rename from src/simagentplg/agent/types.py
rename to src/ejagent/agent/types.py
index 0eff1a4..41b6f6f 100644
--- a/src/simagentplg/agent/types.py
+++ b/src/ejagent/agent/types.py
@@ -3,7 +3,18 @@
 from typing import Any, Protocol
 
 AgentMessage = dict[str, Any]
-INTERNAL_METADATA_PREFIX = "_simagentplg_"
+INTERNAL_METADATA_PREFIX = "_ejagent_"
+LEGACY_INTERNAL_METADATA_PREFIXES = ("_simagentplg_",)
+INTERNAL_METADATA_PREFIXES = (
+    INTERNAL_METADATA_PREFIX,
+    *LEGACY_INTERNAL_METADATA_PREFIXES,
+)
+
+
+def is_internal_metadata_key(key: str) -> bool:
+    """Return whether a message key belongs to current or legacy Core metadata."""
+
+    return key.startswith(INTERNAL_METADATA_PREFIXES)
 
 
 class ToolControl(StrEnum):
diff --git a/src/simagentplg/agent/usage.py b/src/ejagent/agent/usage.py
similarity index 99%
rename from src/simagentplg/agent/usage.py
rename to src/ejagent/agent/usage.py
index 1b85e1f..12dcc52 100644
--- a/src/simagentplg/agent/usage.py
+++ b/src/ejagent/agent/usage.py
@@ -2,7 +2,7 @@
 
 from dataclasses import dataclass
 
-from simagentplg.providers.base import ModelUsage
+from ejagent.providers.base import ModelUsage
 
 
 @dataclass(frozen=True, slots=True)
diff --git a/src/simagentplg/handlers/__init__.py b/src/ejagent/handlers/__init__.py
similarity index 71%
rename from src/simagentplg/handlers/__init__.py
rename to src/ejagent/handlers/__init__.py
index 0a8c72b..35f6314 100644
--- a/src/simagentplg/handlers/__init__.py
+++ b/src/ejagent/handlers/__init__.py
@@ -1,16 +1,16 @@
 """Composable local and external tool handlers."""
 
-from simagentplg.handlers.base import (
+from ejagent.handlers.base import (
     BaseHandler,
     MethodToolHandler,
     UnknownToolError,
 )
-from simagentplg.handlers.definition import (
+from ejagent.handlers.definition import (
     ToolDefinition,
     ToolDefinitionError,
     ToolEffect,
 )
-from simagentplg.handlers.mcp import McpToolHandler
+from ejagent.handlers.mcp import McpToolHandler
 
 __all__ = [
     "BaseHandler",
diff --git a/src/simagentplg/handlers/base.py b/src/ejagent/handlers/base.py
similarity index 96%
rename from src/simagentplg/handlers/base.py
rename to src/ejagent/handlers/base.py
index 38c872c..5232dd1 100644
--- a/src/simagentplg/handlers/base.py
+++ b/src/ejagent/handlers/base.py
@@ -3,12 +3,12 @@
 from inspect import Parameter, signature
 from typing import Any
 
-from simagentplg.agent.cancellation import (
+from ejagent.agent.cancellation import (
     CancellationSource,
     CancellationToken,
 )
-from simagentplg.agent.types import StepOutcome, ToolProgressReporter
-from simagentplg.handlers.definition import (
+from ejagent.agent.types import StepOutcome, ToolProgressReporter
+from ejagent.handlers.definition import (
     ToolDefinition,
     ToolDefinitionError,
     ToolDefinitionInput,
@@ -17,7 +17,7 @@
     normalize_tool_definition,
     normalize_tool_definitions,
 )
-from simagentplg.middleware.base import ToolCallContext
+from ejagent.middleware.base import ToolCallContext
 
 
 class UnknownToolError(KeyError):
diff --git a/src/simagentplg/handlers/definition.py b/src/ejagent/handlers/definition.py
similarity index 100%
rename from src/simagentplg/handlers/definition.py
rename to src/ejagent/handlers/definition.py
diff --git a/src/simagentplg/handlers/mcp.py b/src/ejagent/handlers/mcp.py
similarity index 93%
rename from src/simagentplg/handlers/mcp.py
rename to src/ejagent/handlers/mcp.py
index fa9b330..9042c80 100644
--- a/src/simagentplg/handlers/mcp.py
+++ b/src/ejagent/handlers/mcp.py
@@ -2,16 +2,16 @@
 from pathlib import Path
 from typing import Any
 
-from simagentplg.agent.cancellation import (
+from ejagent.agent.cancellation import (
     CancellationSource,
     CancellationToken,
 )
-from simagentplg.agent.types import StepOutcome, ToolProgressReporter
-from simagentplg.handlers.base import (
+from ejagent.agent.types import StepOutcome, ToolProgressReporter
+from ejagent.handlers.base import (
     BaseHandler,
     UnknownToolError,
 )
-from simagentplg.handlers.definition import (
+from ejagent.handlers.definition import (
     ToolDefinition,
     ToolDefinitionError,
     ToolEffect,
@@ -19,7 +19,7 @@
     normalize_tool_definition,
     normalize_tool_definitions,
 )
-from simagentplg.plugins.mcp.mcp_manager import McpServerManager
+from ejagent.plugins.mcp.mcp_manager import McpServerManager
 
 
 class McpToolHandler(BaseHandler):
diff --git a/src/simagentplg/logger.py b/src/ejagent/logger.py
similarity index 90%
rename from src/simagentplg/logger.py
rename to src/ejagent/logger.py
index e592c34..575f695 100644
--- a/src/simagentplg/logger.py
+++ b/src/ejagent/logger.py
@@ -2,7 +2,7 @@
 
 
 def setup_logger(
-    name: str = "SimAgentPlg",
+    name: str = "ejagent",
     level: str = "INFO",
     fmt: str = "%(asctime)s | %(levelname)-8s | %(name)s | %(message)s",
 ) -> logging.Logger:
@@ -32,7 +32,7 @@ def setup_logger(
     return logger
 
 
-def get_logger(name: str = "SimAgentPlg") -> logging.Logger:
+def get_logger(name: str = "ejagent") -> logging.Logger:
     """Return a configured logger by name.
 
     Args:
diff --git a/src/simagentplg/middleware/__init__.py b/src/ejagent/middleware/__init__.py
similarity index 88%
rename from src/simagentplg/middleware/__init__.py
rename to src/ejagent/middleware/__init__.py
index 858e344..76d1b80 100644
--- a/src/simagentplg/middleware/__init__.py
+++ b/src/ejagent/middleware/__init__.py
@@ -1,6 +1,6 @@
 """Composable middleware for core agent execution."""
 
-from simagentplg.middleware.base import (
+from ejagent.middleware.base import (
     Middleware,
     ToolCallContext,
     ToolMiddleware,
@@ -8,7 +8,7 @@
     compose_tool_middlewares,
     format_tool_call_preview,
 )
-from simagentplg.middleware.policy import (
+from ejagent.middleware.policy import (
     RuleBasedToolPolicy,
     ToolApprovalDecision,
     ToolApprovalRequest,
@@ -20,7 +20,7 @@
     ToolPolicyPredicate,
     ToolPolicyRule,
 )
-from simagentplg.middleware.validation import (
+from ejagent.middleware.validation import (
     ToolSchemaConfigurationError,
     ToolSchemaValidationMiddleware,
 )
diff --git a/src/simagentplg/middleware/base.py b/src/ejagent/middleware/base.py
similarity index 91%
rename from src/simagentplg/middleware/base.py
rename to src/ejagent/middleware/base.py
index bc29dc7..af87a3e 100644
--- a/src/simagentplg/middleware/base.py
+++ b/src/ejagent/middleware/base.py
@@ -5,13 +5,13 @@
 from dataclasses import dataclass
 from typing import TYPE_CHECKING, Any
 
-from simagentplg.agent.types import StepOutcome
+from ejagent.agent.types import StepOutcome
 
 if TYPE_CHECKING:
-    from simagentplg.agent.cancellation import CancellationToken
-    from simagentplg.agent.state import AgentState
-    from simagentplg.agent.types import ToolProgressReporter
-    from simagentplg.handlers.definition import ToolDefinition
+    from ejagent.agent.cancellation import CancellationToken
+    from ejagent.agent.state import AgentState
+    from ejagent.agent.types import ToolProgressReporter
+    from ejagent.handlers.definition import ToolDefinition
 
 
 @dataclass(frozen=True, slots=True)
diff --git a/src/simagentplg/middleware/policy.py b/src/ejagent/middleware/policy.py
similarity index 98%
rename from src/simagentplg/middleware/policy.py
rename to src/ejagent/middleware/policy.py
index acc0d1b..8e256e8 100644
--- a/src/simagentplg/middleware/policy.py
+++ b/src/ejagent/middleware/policy.py
@@ -11,10 +11,10 @@
 from types import MappingProxyType
 from typing import Any, Protocol
 
-from simagentplg.agent.cancellation import AgentCancelledError
-from simagentplg.agent.types import StepOutcome, ToolControl
-from simagentplg.handlers.definition import ToolEffect
-from simagentplg.middleware.base import ToolCallContext, ToolMiddleware, ToolNext
+from ejagent.agent.cancellation import AgentCancelledError
+from ejagent.agent.types import StepOutcome, ToolControl
+from ejagent.handlers.definition import ToolEffect
+from ejagent.middleware.base import ToolCallContext, ToolMiddleware, ToolNext
 
 logger = logging.getLogger(__name__)
 
diff --git a/src/simagentplg/middleware/validation.py b/src/ejagent/middleware/validation.py
similarity index 97%
rename from src/simagentplg/middleware/validation.py
rename to src/ejagent/middleware/validation.py
index f5cd502..6860de6 100644
--- a/src/simagentplg/middleware/validation.py
+++ b/src/ejagent/middleware/validation.py
@@ -10,9 +10,9 @@
 from referencing import Registry
 from referencing.exceptions import Unresolvable
 
-from simagentplg.agent.types import StepOutcome
-from simagentplg.handlers.definition import ToolDefinition
-from simagentplg.middleware.base import ToolCallContext, ToolMiddleware, ToolNext
+from ejagent.agent.types import StepOutcome
+from ejagent.handlers.definition import ToolDefinition
+from ejagent.middleware.base import ToolCallContext, ToolMiddleware, ToolNext
 
 
 class ToolSchemaConfigurationError(ValueError):
diff --git a/src/ejagent/plugins/__init__.py b/src/ejagent/plugins/__init__.py
new file mode 100644
index 0000000..afd4a6b
--- /dev/null
+++ b/src/ejagent/plugins/__init__.py
@@ -0,0 +1,6 @@
+"""Plugin integrations for MCP services and local skills."""
+
+from ejagent.plugins.mcp.mcp_manager import McpServerManager
+from ejagent.plugins.skill.skill_manager import SkillManager
+
+__all__ = ["McpServerManager", "SkillManager"]
diff --git a/src/simagentplg/plugins/mcp/mcp_manager.py b/src/ejagent/plugins/mcp/mcp_manager.py
similarity index 98%
rename from src/simagentplg/plugins/mcp/mcp_manager.py
rename to src/ejagent/plugins/mcp/mcp_manager.py
index 9192005..b8ffc36 100644
--- a/src/simagentplg/plugins/mcp/mcp_manager.py
+++ b/src/ejagent/plugins/mcp/mcp_manager.py
@@ -4,7 +4,7 @@
 from pathlib import Path
 from typing import Any
 
-from simagentplg.logger import get_logger
+from ejagent.logger import get_logger
 
 logger = get_logger(name="MCP")
 
@@ -42,7 +42,7 @@ async def startup(self) -> None:
         except ModuleNotFoundError as exc:
             raise RuntimeError(
                 "MCP integration requires optional dependencies; "
-                "install SimAgentPlg[mcp]"
+                "install ejagent-core[mcp]"
             ) from exc
 
         stack = AsyncExitStack()
diff --git a/src/simagentplg/plugins/skill/skill_manager.py b/src/ejagent/plugins/skill/skill_manager.py
similarity index 99%
rename from src/simagentplg/plugins/skill/skill_manager.py
rename to src/ejagent/plugins/skill/skill_manager.py
index 62f277d..8161433 100644
--- a/src/simagentplg/plugins/skill/skill_manager.py
+++ b/src/ejagent/plugins/skill/skill_manager.py
@@ -5,7 +5,7 @@
 
 import yaml
 
-from simagentplg.logger import get_logger
+from ejagent.logger import get_logger
 
 logger = get_logger("skill")
 
diff --git a/src/simagentplg/providers/__init__.py b/src/ejagent/providers/__init__.py
similarity index 87%
rename from src/simagentplg/providers/__init__.py
rename to src/ejagent/providers/__init__.py
index 9f98145..d0ca850 100644
--- a/src/simagentplg/providers/__init__.py
+++ b/src/ejagent/providers/__init__.py
@@ -1,6 +1,6 @@
 """Model provider adapters for the agent core."""
 
-from simagentplg.providers.base import (
+from ejagent.providers.base import (
     AssistantMessage,
     ContextOverflowError,
     ModelAdapter,
@@ -16,7 +16,7 @@
     ModelToolCall,
     ModelUsage,
 )
-from simagentplg.providers.openai import ModelConfig, OpenAIModelAdapter
+from ejagent.providers.openai import ModelConfig, OpenAIModelAdapter
 
 __all__ = [
     "AssistantMessage",
diff --git a/src/simagentplg/providers/base.py b/src/ejagent/providers/base.py
similarity index 98%
rename from src/simagentplg/providers/base.py
rename to src/ejagent/providers/base.py
index c446fb9..32149b9 100644
--- a/src/simagentplg/providers/base.py
+++ b/src/ejagent/providers/base.py
@@ -7,8 +7,8 @@
 from typing import TYPE_CHECKING, Any, TypeAlias
 
 if TYPE_CHECKING:
-    from simagentplg.agent.cancellation import CancellationToken
-    from simagentplg.agent.context_builder import ContextBuildResult
+    from ejagent.agent.cancellation import CancellationToken
+    from ejagent.agent.context_builder import ContextBuildResult
 
 
 class ModelErrorKind(StrEnum):
diff --git a/src/simagentplg/providers/openai.py b/src/ejagent/providers/openai.py
similarity index 98%
rename from src/simagentplg/providers/openai.py
rename to src/ejagent/providers/openai.py
index 8f361b3..6d92155 100644
--- a/src/simagentplg/providers/openai.py
+++ b/src/ejagent/providers/openai.py
@@ -16,8 +16,8 @@
     RateLimitError,
 )
 
-from simagentplg.agent.cancellation import AgentCancelledError
-from simagentplg.providers.base import (
+from ejagent.agent.cancellation import AgentCancelledError
+from ejagent.providers.base import (
     AssistantMessage,
     ContextOverflowError,
     ModelAdapter,
@@ -34,8 +34,8 @@
 )
 
 if TYPE_CHECKING:
-    from simagentplg.agent.cancellation import CancellationToken
-    from simagentplg.agent.context_builder import ContextBuildResult
+    from ejagent.agent.cancellation import CancellationToken
+    from ejagent.agent.context_builder import ContextBuildResult
 
 
 @dataclass(frozen=True, slots=True)
diff --git a/src/simagentplg/py.typed b/src/ejagent/py.typed
similarity index 100%
rename from src/simagentplg/py.typed
rename to src/ejagent/py.typed
diff --git a/src/simagentplg/session/__init__.py b/src/ejagent/session/__init__.py
similarity index 76%
rename from src/simagentplg/session/__init__.py
rename to src/ejagent/session/__init__.py
index 687638b..d6ba0dc 100644
--- a/src/simagentplg/session/__init__.py
+++ b/src/ejagent/session/__init__.py
@@ -1,39 +1,39 @@
 """Durable Agent Session projections built from lifecycle event trees."""
 
-from simagentplg.session.codec import (
+from ejagent.session.codec import (
     SESSION_SCHEMA_VERSION,
     session_from_dict,
     session_to_dict,
 )
-from simagentplg.session.errors import (
+from ejagent.session.errors import (
     SessionConflictError,
     SessionError,
     SessionLockTimeoutError,
     SessionSerializationError,
     SessionStorageError,
 )
-from simagentplg.session.journal import (
+from ejagent.session.journal import (
     DEFAULT_SESSION_BRANCH,
     SESSION_JOURNAL_SCHEMA_VERSION,
     SessionRecord,
     SessionRecordDraft,
     SessionRecordKind,
 )
-from simagentplg.session.jsonl import JsonlSessionStorage
-from simagentplg.session.memory import MemorySessionStorage
-from simagentplg.session.recorder import SessionRecorder
-from simagentplg.session.storage import (
+from ejagent.session.jsonl import JsonlSessionStorage
+from ejagent.session.memory import MemorySessionStorage
+from ejagent.session.recorder import SessionRecorder
+from ejagent.session.storage import (
     SessionJournalStorage,
     SessionStorage,
     SessionTreeStorage,
 )
-from simagentplg.session.tree import (
+from ejagent.session.tree import (
     SessionBranch,
     SessionBranchIntent,
     SessionCheckout,
     SessionRetry,
 )
-from simagentplg.session.types import (
+from ejagent.session.types import (
     AgentSession,
     SessionCompaction,
     SessionMessage,
diff --git a/src/simagentplg/session/_file_lock.py b/src/ejagent/session/_file_lock.py
similarity index 99%
rename from src/simagentplg/session/_file_lock.py
rename to src/ejagent/session/_file_lock.py
index 3217ff2..50b0ff3 100644
--- a/src/simagentplg/session/_file_lock.py
+++ b/src/ejagent/session/_file_lock.py
@@ -11,7 +11,7 @@
 from pathlib import Path
 from typing import Any
 
-from simagentplg.session.errors import (
+from ejagent.session.errors import (
     SessionLockTimeoutError,
     SessionStorageError,
 )
diff --git a/src/simagentplg/session/codec.py b/src/ejagent/session/codec.py
similarity index 97%
rename from src/simagentplg/session/codec.py
rename to src/ejagent/session/codec.py
index e4a0488..9a6c0d2 100644
--- a/src/simagentplg/session/codec.py
+++ b/src/ejagent/session/codec.py
@@ -4,11 +4,11 @@
 from copy import deepcopy
 from typing import Any
 
-from simagentplg.agent.compaction import SummaryEntry
-from simagentplg.agent.result import AgentRunResult, RunStatus, StopReason
-from simagentplg.agent.usage import RunUsage
-from simagentplg.session.errors import SessionSerializationError
-from simagentplg.session.types import (
+from ejagent.agent.compaction import SummaryEntry
+from ejagent.agent.result import AgentRunResult, RunStatus, StopReason
+from ejagent.agent.usage import RunUsage
+from ejagent.session.errors import SessionSerializationError
+from ejagent.session.types import (
     AgentSession,
     SessionCompaction,
     SessionMessage,
diff --git a/src/simagentplg/session/errors.py b/src/ejagent/session/errors.py
similarity index 100%
rename from src/simagentplg/session/errors.py
rename to src/ejagent/session/errors.py
diff --git a/src/simagentplg/session/journal.py b/src/ejagent/session/journal.py
similarity index 98%
rename from src/simagentplg/session/journal.py
rename to src/ejagent/session/journal.py
index 580ac58..676d465 100644
--- a/src/simagentplg/session/journal.py
+++ b/src/ejagent/session/journal.py
@@ -6,17 +6,17 @@
 from enum import StrEnum
 from typing import Any
 
-from simagentplg.agent.compaction import CompactionResult, SummaryEntry
-from simagentplg.agent.result import AgentRunResult
-from simagentplg.agent.types import AgentMessage
-from simagentplg.session.codec import (
+from ejagent.agent.compaction import CompactionResult, SummaryEntry
+from ejagent.agent.result import AgentRunResult
+from ejagent.agent.types import AgentMessage
+from ejagent.session.codec import (
     agent_run_result_from_dict,
     agent_run_result_to_dict,
     session_from_dict,
     session_to_dict,
 )
-from simagentplg.session.errors import SessionSerializationError
-from simagentplg.session.types import AgentSession
+from ejagent.session.errors import SessionSerializationError
+from ejagent.session.types import AgentSession
 
 SESSION_JOURNAL_SCHEMA_VERSION = 1
 DEFAULT_SESSION_BRANCH = "main"
diff --git a/src/simagentplg/session/jsonl.py b/src/ejagent/session/jsonl.py
similarity index 99%
rename from src/simagentplg/session/jsonl.py
rename to src/ejagent/session/jsonl.py
index 4150f47..53eb704 100644
--- a/src/simagentplg/session/jsonl.py
+++ b/src/ejagent/session/jsonl.py
@@ -12,26 +12,26 @@
 from typing import Any, TypeVar
 from uuid import uuid4
 
-from simagentplg.session._file_lock import SessionFileLock
-from simagentplg.session.errors import (
+from ejagent.session._file_lock import SessionFileLock
+from ejagent.session.errors import (
     SessionConflictError,
     SessionSerializationError,
     SessionStorageError,
 )
-from simagentplg.session.journal import (
+from ejagent.session.journal import (
     DEFAULT_SESSION_BRANCH,
     SessionRecord,
     SessionRecordDraft,
     SessionRecordKind,
     apply_session_record,
 )
-from simagentplg.session.tree import (
+from ejagent.session.tree import (
     SessionBranch,
     SessionBranchIntent,
     SessionCheckout,
     SessionRetry,
 )
-from simagentplg.session.types import AgentSession
+from ejagent.session.types import AgentSession
 
 _ResultT = TypeVar("_ResultT")
 
diff --git a/src/simagentplg/session/memory.py b/src/ejagent/session/memory.py
similarity index 92%
rename from src/simagentplg/session/memory.py
rename to src/ejagent/session/memory.py
index 3671874..90eebdb 100644
--- a/src/simagentplg/session/memory.py
+++ b/src/ejagent/session/memory.py
@@ -1,6 +1,6 @@
 import asyncio
 
-from simagentplg.session.types import AgentSession
+from ejagent.session.types import AgentSession
 
 
 class MemorySessionStorage:
diff --git a/src/simagentplg/session/recorder.py b/src/ejagent/session/recorder.py
similarity index 95%
rename from src/simagentplg/session/recorder.py
rename to src/ejagent/session/recorder.py
index 35a0efe..726f9f0 100644
--- a/src/simagentplg/session/recorder.py
+++ b/src/ejagent/session/recorder.py
@@ -1,6 +1,6 @@
 import asyncio
 
-from simagentplg.agent.events import (
+from ejagent.agent.events import (
     AgentContinued,
     AgentEvent,
     AgentFinished,
@@ -10,10 +10,10 @@
     SteeringApplied,
     ToolCompleted,
 )
-from simagentplg.providers.base import serialize_assistant_message
-from simagentplg.session.journal import DEFAULT_SESSION_BRANCH, SessionRecordDraft
-from simagentplg.session.storage import SessionJournalStorage, SessionStorage
-from simagentplg.session.types import AgentSession
+from ejagent.providers.base import serialize_assistant_message
+from ejagent.session.journal import DEFAULT_SESSION_BRANCH, SessionRecordDraft
+from ejagent.session.storage import SessionJournalStorage, SessionStorage
+from ejagent.session.types import AgentSession
 
 _RECORDED_PAYLOADS = (
     AgentStarted,
diff --git a/src/simagentplg/session/storage.py b/src/ejagent/session/storage.py
similarity index 93%
rename from src/simagentplg/session/storage.py
rename to src/ejagent/session/storage.py
index 7ee8730..089767a 100644
--- a/src/simagentplg/session/storage.py
+++ b/src/ejagent/session/storage.py
@@ -1,12 +1,12 @@
 from typing import Protocol, runtime_checkable
 
-from simagentplg.session.journal import (
+from ejagent.session.journal import (
     DEFAULT_SESSION_BRANCH,
     SessionRecord,
     SessionRecordDraft,
 )
-from simagentplg.session.tree import SessionBranch, SessionCheckout, SessionRetry
-from simagentplg.session.types import AgentSession
+from ejagent.session.tree import SessionBranch, SessionCheckout, SessionRetry
+from ejagent.session.types import AgentSession
 
 
 class SessionStorage(Protocol):
diff --git a/src/simagentplg/session/tree.py b/src/ejagent/session/tree.py
similarity index 93%
rename from src/simagentplg/session/tree.py
rename to src/ejagent/session/tree.py
index 16c14ad..2a27c27 100644
--- a/src/simagentplg/session/tree.py
+++ b/src/ejagent/session/tree.py
@@ -3,8 +3,8 @@
 from dataclasses import dataclass
 from enum import StrEnum
 
-from simagentplg.session.journal import SessionRecord
-from simagentplg.session.types import AgentSession
+from ejagent.session.journal import SessionRecord
+from ejagent.session.types import AgentSession
 
 
 class SessionBranchIntent(StrEnum):
diff --git a/src/simagentplg/session/types.py b/src/ejagent/session/types.py
similarity index 98%
rename from src/simagentplg/session/types.py
rename to src/ejagent/session/types.py
index a4bdc17..bf846d4 100644
--- a/src/simagentplg/session/types.py
+++ b/src/ejagent/session/types.py
@@ -4,9 +4,9 @@
 from dataclasses import dataclass, field, replace
 from enum import StrEnum
 
-from simagentplg.agent.compaction import SummaryEntry
-from simagentplg.agent.result import AgentRunResult
-from simagentplg.agent.types import AgentMessage
+from ejagent.agent.compaction import SummaryEntry
+from ejagent.agent.result import AgentRunResult
+from ejagent.agent.types import AgentMessage
 
 
 class SessionRunIntent(StrEnum):
diff --git a/src/simagentplg/plugins/__init__.py b/src/simagentplg/plugins/__init__.py
deleted file mode 100644
index 4df7171..0000000
--- a/src/simagentplg/plugins/__init__.py
+++ /dev/null
@@ -1,6 +0,0 @@
-"""Plugin integrations for MCP services and local skills."""
-
-from simagentplg.plugins.mcp.mcp_manager import McpServerManager
-from simagentplg.plugins.skill.skill_manager import SkillManager
-
-__all__ = ["McpServerManager", "SkillManager"]
diff --git a/tests/package_artifact_smoke.py b/tests/package_artifact_smoke.py
index 08b57e1..10eaba1 100644
--- a/tests/package_artifact_smoke.py
+++ b/tests/package_artifact_smoke.py
@@ -37,13 +37,19 @@ def main() -> None:
 
     with zipfile.ZipFile(wheel) as archive:
         names = archive.namelist()
-        if "simagentplg/py.typed" not in names:
-            raise AssertionError("wheel is missing simagentplg/py.typed")
+        if "ejagent/py.typed" not in names:
+            raise AssertionError("wheel is missing ejagent/py.typed")
+        if any(name.startswith("simagentplg/") for name in names):
+            raise AssertionError("wheel unexpectedly contains the legacy package")
         metadata_name = next(
             name for name in names if name.endswith(".dist-info/METADATA")
         )
         metadata = archive.read(metadata_name).decode()
 
+    if "Name: ejagent-core\n" not in metadata:
+        raise AssertionError("wheel metadata has the wrong distribution name")
+    if "Version: 0.6.0\n" not in metadata:
+        raise AssertionError("wheel metadata has the wrong distribution version")
     if "Provides-Extra: mcp" not in metadata:
         raise AssertionError("wheel metadata does not declare the mcp extra")
     fastmcp_requirements = [
diff --git a/tests/public_api_smoke.py b/tests/public_api_smoke.py
index 79f0da7..881692a 100644
--- a/tests/public_api_smoke.py
+++ b/tests/public_api_smoke.py
@@ -16,11 +16,13 @@ def main() -> None:
 
     if args.expect_no_mcp and importlib.util.find_spec("fastmcp") is not None:
         raise AssertionError("fastmcp must not be installed by the core package")
+    if importlib.util.find_spec("simagentplg") is not None:
+        raise AssertionError("the legacy simagentplg import must not be installed")
 
-    import simagentplg
+    import ejagent
 
     missing_attributes = [
-        name for name in simagentplg.__all__ if not hasattr(simagentplg, name)
+        name for name in ejagent.__all__ if not hasattr(ejagent, name)
     ]
     if missing_attributes:
         raise AssertionError(
@@ -87,25 +89,25 @@ def main() -> None:
         "session_to_dict",
         "session_from_dict",
     }
-    missing_exports = required_exports.difference(simagentplg.__all__)
+    missing_exports = required_exports.difference(ejagent.__all__)
     if missing_exports:
         raise AssertionError(
             f"required public exports are missing: {', '.join(sorted(missing_exports))}"
         )
 
-    if not files("simagentplg").joinpath("py.typed").is_file():
+    if not files("ejagent").joinpath("py.typed").is_file():
         raise AssertionError("installed package is missing the py.typed marker")
-    if not version("SimAgentPlg"):
-        raise AssertionError("installed distribution has no version")
+    if version("ejagent-core") != "0.6.0":
+        raise AssertionError("installed distribution has the wrong version")
 
     if args.expect_no_mcp:
 
         async def check_missing_mcp_message() -> None:
-            manager = simagentplg.McpServerManager("unused.json")
+            manager = ejagent.McpServerManager("unused.json")
             try:
                 await manager.startup()
             except RuntimeError as exc:
-                if "SimAgentPlg[mcp]" not in str(exc):
+                if "ejagent-core[mcp]" not in str(exc):
                     raise AssertionError(
                         "missing MCP dependencies produced no install guidance"
                     ) from exc
diff --git a/tests/test_agent.py b/tests/test_agent.py
index 548ebae..0554c80 100644
--- a/tests/test_agent.py
+++ b/tests/test_agent.py
@@ -9,7 +9,7 @@
 from typing import Any
 from unittest.mock import patch
 
-from simagentplg import (
+from ejagent import (
     AgentContextBuilder,
     AgentOrchestrator,
     AgentRunError,
@@ -33,12 +33,12 @@
     ToolMiddleware,
     ToolNext,
 )
-from simagentplg.agent.base import (
+from ejagent.agent.base import (
     DEFAULT_SYSTEM_PROMPT,
     EXPLICIT_FINISH_PROTOCOL_PROMPT,
     TOOL_PROTOCOL_PROMPT,
 )
-from simagentplg.agent.orchestrator import TOOL_COMPLETION_RETRY_PROMPT
+from ejagent.agent.orchestrator import TOOL_COMPLETION_RETRY_PROMPT
 
 TEST_CONFIG = ModelConfig(
     model="test-model",
@@ -328,7 +328,7 @@ async def test_base_agent_owns_model_adapter_lifecycle(self) -> None:
 
     async def test_model_config_reads_chat_model_from_env(self) -> None:
         with (
-            patch("simagentplg.providers.openai.load_dotenv"),
+            patch("ejagent.providers.openai.load_dotenv"),
             patch.dict(
                 "os.environ",
                 {
diff --git a/tests/test_agent_cancellation.py b/tests/test_agent_cancellation.py
index f38132b..e86ae11 100644
--- a/tests/test_agent_cancellation.py
+++ b/tests/test_agent_cancellation.py
@@ -3,7 +3,7 @@
 import unittest
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AgentFinished,
     AgentStarted,
diff --git a/tests/test_agent_continue.py b/tests/test_agent_continue.py
index 00657c9..38082ba 100644
--- a/tests/test_agent_continue.py
+++ b/tests/test_agent_continue.py
@@ -3,7 +3,7 @@
 import unittest
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentContinued,
     AgentEvent,
     AgentFinished,
diff --git a/tests/test_agent_events.py b/tests/test_agent_events.py
index 9092060..e7d07ca 100644
--- a/tests/test_agent_events.py
+++ b/tests/test_agent_events.py
@@ -2,7 +2,7 @@
 from dataclasses import FrozenInstanceError
 from typing import Any, get_type_hints
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AgentFinished,
     AgentStarted,
diff --git a/tests/test_agent_follow_up.py b/tests/test_agent_follow_up.py
index 0e7bb58..d109645 100644
--- a/tests/test_agent_follow_up.py
+++ b/tests/test_agent_follow_up.py
@@ -3,7 +3,7 @@
 import unittest
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AgentFinished,
     AgentStarted,
diff --git a/tests/test_agent_session.py b/tests/test_agent_session.py
index 4d98c21..ed04fe5 100644
--- a/tests/test_agent_session.py
+++ b/tests/test_agent_session.py
@@ -1,7 +1,7 @@
 import unittest
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AgentRunResult,
     AgentSession,
diff --git a/tests/test_agent_steering.py b/tests/test_agent_steering.py
index de4162f..93da522 100644
--- a/tests/test_agent_steering.py
+++ b/tests/test_agent_steering.py
@@ -3,7 +3,7 @@
 import unittest
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AssistantMessage,
     BaseAgent,
diff --git a/tests/test_agent_streaming.py b/tests/test_agent_streaming.py
index 0a480b8..fdd22bf 100644
--- a/tests/test_agent_streaming.py
+++ b/tests/test_agent_streaming.py
@@ -4,7 +4,7 @@
 from types import SimpleNamespace
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentContextBuilder,
     AgentEvent,
     AgentFinished,
diff --git a/tests/test_auto_compaction.py b/tests/test_auto_compaction.py
index 1b46306..27673ee 100644
--- a/tests/test_auto_compaction.py
+++ b/tests/test_auto_compaction.py
@@ -3,7 +3,7 @@
 from collections.abc import AsyncIterator, Mapping, Sequence
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AssistantMessage,
     AssistantTextDelta,
@@ -249,7 +249,7 @@ async def test_pressure_compactor_failure_stops_safely(self) -> None:
         self.assertEqual(result.error, "summary provider failed")
         self.assertEqual(model.contexts, [])
         self.assertIn("old task", repr(agent.messages))
-        self.assertNotIn("_simagentplg_summary", repr(agent.messages))
+        self.assertNotIn("_ejagent_summary", repr(agent.messages))
 
     async def test_abort_cancels_automatic_compaction(self) -> None:
         model = ScriptedStreamModel([completed()])
diff --git a/tests/test_behavior_hooks.py b/tests/test_behavior_hooks.py
index 1d1cb0f..529f151 100644
--- a/tests/test_behavior_hooks.py
+++ b/tests/test_behavior_hooks.py
@@ -3,7 +3,7 @@
 import unittest
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AgentFinished,
     AssistantMessage,
diff --git a/tests/test_context_compaction.py b/tests/test_context_compaction.py
index 3df6eab..bad662a 100644
--- a/tests/test_context_compaction.py
+++ b/tests/test_context_compaction.py
@@ -4,7 +4,7 @@
 from copy import deepcopy
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AssistantMessage,
     BaseAgent,
@@ -178,7 +178,7 @@ async def test_explicit_compaction_atomically_replaces_old_turns(self) -> None:
             ["system", "system", "user", "assistant"],
         )
         summary_message = agent.messages[1]
-        self.assertIn("_simagentplg_summary", summary_message)
+        self.assertIn("_ejagent_summary", summary_message)
         self.assertNotIn("old-call", repr(agent.messages))
         self.assertEqual(
             [type(event.payload) for event in sink.events],
@@ -193,7 +193,7 @@ async def test_explicit_compaction_atomically_replaces_old_turns(self) -> None:
 
         await agent.run(task="continue from the summary")
         sent_summary = model.contexts[0].llm_messages[1]
-        self.assertNotIn("_simagentplg_summary", sent_summary)
+        self.assertNotIn("_ejagent_summary", sent_summary)
         self.assertIn("Conversation summary", sent_summary["content"])
 
     async def test_compactor_failure_keeps_history_unchanged(self) -> None:
@@ -345,7 +345,7 @@ async def test_repeated_compaction_replaces_and_merges_summary(self) -> None:
             "first summary",
         )
         summary_messages = [
-            message for message in agent.messages if "_simagentplg_summary" in message
+            message for message in agent.messages if "_ejagent_summary" in message
         ]
         self.assertEqual(len(summary_messages), 1)
         assert second.summary is not None
@@ -423,7 +423,7 @@ async def test_session_restores_compacted_projection_and_new_runs(
             [message["role"] for message in session.messages],
             ["system", "user", "assistant", "user", "assistant"],
         )
-        self.assertIn("_simagentplg_summary", session.messages[0])
+        self.assertIn("_ejagent_summary", session.messages[0])
 
         resumed_model = QueueModel(["resumed"])
         resumed = BaseAgent(
@@ -435,7 +435,7 @@ async def test_session_restores_compacted_projection_and_new_runs(
 
         llm_summary = resumed_model.contexts[0].llm_messages[1]
         self.assertIn("Conversation summary", llm_summary["content"])
-        self.assertNotIn("_simagentplg_summary", llm_summary)
+        self.assertNotIn("_ejagent_summary", llm_summary)
 
     async def test_session_keeps_audit_entries_covered_by_compaction(
         self,
diff --git a/tests/test_context_management.py b/tests/test_context_management.py
index c883eb5..eb84db2 100644
--- a/tests/test_context_management.py
+++ b/tests/test_context_management.py
@@ -2,10 +2,12 @@
 from collections.abc import Mapping, Sequence
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
+    AgentContextBuilder,
     AgentEvent,
     AgentFinished,
     AgentStarted,
+    AgentState,
     AssistantMessage,
     BaseAgent,
     CancellationToken,
@@ -51,6 +53,30 @@ async def complete(
 
 
 class ContextManagementTests(unittest.IsolatedAsyncioTestCase):
+    def test_context_builder_strips_current_and_legacy_internal_metadata(self) -> None:
+        state = AgentState(
+            messages=[
+                {
+                    "role": "system",
+                    "content": "summary",
+                    "_ejagent_summary": {"content": "current"},
+                    "_simagentplg_summary": {"content": "legacy"},
+                }
+            ]
+        )
+
+        context = AgentContextBuilder().build(state)
+
+        self.assertEqual(
+            context.agent_messages[0]["_ejagent_summary"], {"content": "current"}
+        )
+        self.assertEqual(
+            context.agent_messages[0]["_simagentplg_summary"],
+            {"content": "legacy"},
+        )
+        self.assertNotIn("_ejagent_summary", context.llm_messages[0])
+        self.assertNotIn("_simagentplg_summary", context.llm_messages[0])
+
     def test_heuristic_is_utf8_aware_and_ignores_usage_metadata(self) -> None:
         estimator = HeuristicMessageTokenEstimator()
         english = {"role": "user", "content": "a" * 40}
@@ -65,10 +91,16 @@ def test_heuristic_is_utf8_aware_and_ignores_usage_metadata(self) -> None:
         }
         with_internal_summary = {
             **english,
-            "_simagentplg_summary": {
+            "_ejagent_summary": {
                 "content": "internal metadata must not be counted" * 100,
             },
         }
+        with_legacy_internal_summary = {
+            **english,
+            "_simagentplg_summary": {
+                "content": "legacy internal metadata must not be counted" * 100,
+            },
+        }
 
         self.assertGreater(
             estimator.estimate_message(chinese),
@@ -82,6 +114,10 @@ def test_heuristic_is_utf8_aware_and_ignores_usage_metadata(self) -> None:
             estimator.estimate_message(english),
             estimator.estimate_message(with_internal_summary),
         )
+        self.assertEqual(
+            estimator.estimate_message(english),
+            estimator.estimate_message(with_legacy_internal_summary),
+        )
 
     def test_estimate_without_usage_includes_messages_and_tools(self) -> None:
         estimate = estimate_context_usage(
diff --git a/tests/test_examples.py b/tests/test_examples.py
index cd9f67e..3fbbce6 100644
--- a/tests/test_examples.py
+++ b/tests/test_examples.py
@@ -2,7 +2,7 @@
 import unittest
 from pathlib import Path
 
-from simagentplg import MethodToolHandler, OpenAIModelAdapter, SkillManager
+from ejagent import MethodToolHandler, OpenAIModelAdapter, SkillManager
 
 EXAMPLES_DIR = Path(__file__).parents[1] / "examples"
 
diff --git a/tests/test_mcp_manager.py b/tests/test_mcp_manager.py
index 0ae0be2..6096da4 100644
--- a/tests/test_mcp_manager.py
+++ b/tests/test_mcp_manager.py
@@ -3,7 +3,7 @@
 from types import SimpleNamespace
 from typing import Any
 
-from simagentplg.plugins.mcp.mcp_manager import McpServerManager
+from ejagent.plugins.mcp.mcp_manager import McpServerManager
 
 
 class FakeMcpClient:
diff --git a/tests/test_model_compactor.py b/tests/test_model_compactor.py
index 1ec437a..a6d24b1 100644
--- a/tests/test_model_compactor.py
+++ b/tests/test_model_compactor.py
@@ -1,6 +1,6 @@
 import unittest
 
-from simagentplg import (
+from ejagent import (
     AgentContextBuilder,
     AgentState,
     AssistantMessage,
diff --git a/tests/test_parallel_tool_calls.py b/tests/test_parallel_tool_calls.py
index 61ba796..bbff2b4 100644
--- a/tests/test_parallel_tool_calls.py
+++ b/tests/test_parallel_tool_calls.py
@@ -3,7 +3,7 @@
 import unittest
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AssistantMessage,
     BaseAgent,
diff --git a/tests/test_provider_errors.py b/tests/test_provider_errors.py
index d13c73b..cdd49cf 100644
--- a/tests/test_provider_errors.py
+++ b/tests/test_provider_errors.py
@@ -3,7 +3,7 @@
 import httpx
 from openai import APITimeoutError, AuthenticationError, RateLimitError
 
-from simagentplg import (
+from ejagent import (
     ContextOverflowError,
     ModelAuthenticationError,
     ModelErrorKind,
@@ -11,7 +11,7 @@
     ModelRateLimitError,
     ModelTimeoutError,
 )
-from simagentplg.providers.openai import _normalize_provider_error
+from ejagent.providers.openai import _normalize_provider_error
 
 
 class StructuredProviderError(Exception):
diff --git a/tests/test_session_persistence.py b/tests/test_session_persistence.py
index 4644c2c..a2c3184 100644
--- a/tests/test_session_persistence.py
+++ b/tests/test_session_persistence.py
@@ -8,7 +8,7 @@
 from typing import Any
 from unittest.mock import patch
 
-from simagentplg import (
+from ejagent import (
     SESSION_SCHEMA_VERSION,
     AgentRunResult,
     AgentSession,
@@ -182,7 +182,7 @@ def start_append_process(
 import sys
 import time
 from pathlib import Path
-from simagentplg import (
+from ejagent import (
     JsonlSessionStorage,
     SessionConflictError,
     SessionRecordDraft,
@@ -392,7 +392,7 @@ async def test_failed_append_preserves_previous_journal(self) -> None:
 
             with (
                 patch(
-                    "simagentplg.session.jsonl.os.write",
+                    "ejagent.session.jsonl.os.write",
                     side_effect=OSError("disk failure"),
                 ),
                 self.assertRaises(SessionStorageError),
@@ -410,7 +410,7 @@ async def test_separate_python_process_loads_saved_session(self) -> None:
 import asyncio
 import json
 import sys
-from simagentplg import JsonlSessionStorage
+from ejagent import JsonlSessionStorage
 
 async def main():
     session = await JsonlSessionStorage(sys.argv[1]).load(sys.argv[2])
diff --git a/tests/test_tool_definitions.py b/tests/test_tool_definitions.py
index 0bb8521..fcb26e7 100644
--- a/tests/test_tool_definitions.py
+++ b/tests/test_tool_definitions.py
@@ -2,7 +2,7 @@
 from types import SimpleNamespace
 from typing import Any, cast
 
-from simagentplg import (
+from ejagent import (
     AgentContextBuilder,
     AgentState,
     AssistantMessage,
diff --git a/tests/test_tool_policy.py b/tests/test_tool_policy.py
index ebf3b74..1259166 100644
--- a/tests/test_tool_policy.py
+++ b/tests/test_tool_policy.py
@@ -5,7 +5,7 @@
 import unittest
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AssistantMessage,
     BaseAgent,
     CancellationToken,
@@ -28,7 +28,7 @@
     ToolPolicyMiddleware,
     ToolPolicyRule,
 )
-from simagentplg.agent.state import AgentState
+from ejagent.agent.state import AgentState
 
 READ_TOOL = ToolDefinition(
     name="read",
@@ -342,7 +342,7 @@ async def test_approval_exception_fails_closed(self) -> None:
             middlewares=[ToolPolicyMiddleware(policy, approver=RaisingApprover())],
         )
 
-        with self.assertLogs("simagentplg.middleware.policy", level="ERROR"):
+        with self.assertLogs("ejagent.middleware.policy", level="ERROR"):
             outcome = await agent.dispatch("write", {"path": "/tmp/a"})
 
         self.assertEqual(outcome.control.value, "reject")
@@ -358,7 +358,7 @@ async def test_policy_exception_fails_closed(self) -> None:
             middlewares=[ToolPolicyMiddleware(RaisingPolicy())],
         )
 
-        with self.assertLogs("simagentplg.middleware.policy", level="ERROR"):
+        with self.assertLogs("ejagent.middleware.policy", level="ERROR"):
             outcome = await agent.dispatch("read", {"path": "/tmp/a"})
 
         self.assertEqual(outcome.control.value, "reject")
diff --git a/tests/test_tool_progress.py b/tests/test_tool_progress.py
index 28b790d..1af7bc8 100644
--- a/tests/test_tool_progress.py
+++ b/tests/test_tool_progress.py
@@ -3,7 +3,7 @@
 from dataclasses import FrozenInstanceError
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentEvent,
     AssistantMessage,
     BaseAgent,
diff --git a/tests/test_tool_validation.py b/tests/test_tool_validation.py
index 1e100a1..ce8714f 100644
--- a/tests/test_tool_validation.py
+++ b/tests/test_tool_validation.py
@@ -4,7 +4,7 @@
 import unittest
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentRunResult,
     AssistantMessage,
     BaseAgent,
diff --git a/tests/test_usage_budget.py b/tests/test_usage_budget.py
index 5cb5f44..a0e6bcb 100644
--- a/tests/test_usage_budget.py
+++ b/tests/test_usage_budget.py
@@ -3,7 +3,7 @@
 from types import SimpleNamespace
 from typing import Any
 
-from simagentplg import (
+from ejagent import (
     AgentContextBuilder,
     AgentEvent,
     AgentState,
diff --git a/uv.lock b/uv.lock
index 605b32d..f646d7f 100644
--- a/uv.lock
+++ b/uv.lock
@@ -324,6 +324,50 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/a7/5f/ed01f9a3cdffbd5a008556fc7b2a08ddb1cc6ace7effa7340604b1d16699/docstring_parser-0.18.0-py3-none-any.whl", hash = "sha256:b3fcbed555c47d8479be0796ef7e19c2670d428d72e96da63f3a40122860374b", size = 22484, upload-time = "2026-04-14T04:09:18.638Z" },
 ]
 
+[[package]]
+name = "ejagent-core"
+version = "0.6.0"
+source = { editable = "." }
+dependencies = [
+    { name = "jsonschema" },
+    { name = "openai" },
+    { name = "python-dotenv" },
+    { name = "pyyaml" },
+    { name = "referencing" },
+]
+
+[package.optional-dependencies]
+mcp = [
+    { name = "fastmcp" },
+]
+
+[package.dev-dependencies]
+dev = [
+    { name = "mypy" },
+    { name = "ruff" },
+    { name = "types-jsonschema" },
+    { name = "types-pyyaml" },
+]
+
+[package.metadata]
+requires-dist = [
+    { name = "fastmcp", marker = "extra == 'mcp'", specifier = ">=3.4.2" },
+    { name = "jsonschema", specifier = ">=4.26.0" },
+    { name = "openai", specifier = ">=2.41.0" },
+    { name = "python-dotenv", specifier = ">=1.2.2" },
+    { name = "pyyaml", specifier = ">=6.0.3" },
+    { name = "referencing", specifier = ">=0.37.0" },
+]
+provides-extras = ["mcp"]
+
+[package.metadata.requires-dev]
+dev = [
+    { name = "mypy", specifier = ">=1.18.2" },
+    { name = "ruff", specifier = ">=0.14.0" },
+    { name = "types-jsonschema", specifier = ">=4.26.0.20260518" },
+    { name = "types-pyyaml", specifier = ">=6.0.12.20250915" },
+]
+
 [[package]]
 name = "email-validator"
 version = "2.3.0"
@@ -1375,50 +1419,6 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/b7/46/f5af3402b579fd5e11573ce652019a67074317e18c1935cc0b4ba9b35552/secretstorage-3.5.0-py3-none-any.whl", hash = "sha256:0ce65888c0725fcb2c5bc0fdb8e5438eece02c523557ea40ce0703c266248137", size = 15554, upload-time = "2025-11-23T19:02:51.545Z" },
 ]
 
-[[package]]
-name = "simagentplg"
-version = "0.5.0"
-source = { editable = "." }
-dependencies = [
-    { name = "jsonschema" },
-    { name = "openai" },
-    { name = "python-dotenv" },
-    { name = "pyyaml" },
-    { name = "referencing" },
-]
-
-[package.optional-dependencies]
-mcp = [
-    { name = "fastmcp" },
-]
-
-[package.dev-dependencies]
-dev = [
-    { name = "mypy" },
-    { name = "ruff" },
-    { name = "types-jsonschema" },
-    { name = "types-pyyaml" },
-]
-
-[package.metadata]
-requires-dist = [
-    { name = "fastmcp", marker = "extra == 'mcp'", specifier = ">=3.4.2" },
-    { name = "jsonschema", specifier = ">=4.26.0" },
-    { name = "openai", specifier = ">=2.41.0" },
-    { name = "python-dotenv", specifier = ">=1.2.2" },
-    { name = "pyyaml", specifier = ">=6.0.3" },
-    { name = "referencing", specifier = ">=0.37.0" },
-]
-provides-extras = ["mcp"]
-
-[package.metadata.requires-dev]
-dev = [
-    { name = "mypy", specifier = ">=1.18.2" },
-    { name = "ruff", specifier = ">=0.14.0" },
-    { name = "types-jsonschema", specifier = ">=4.26.0.20260518" },
-    { name = "types-pyyaml", specifier = ">=6.0.12.20250915" },
-]
-
 [[package]]
 name = "sniffio"
 version = "1.3.1"