diff --git a/docs/api_to_audit.md b/docs/api_to_audit.md
index b6bcce73b0..5cc98f19e1 100644
--- a/docs/api_to_audit.md
+++ b/docs/api_to_audit.md
@@ -17,6 +17,38 @@ content-block vocabulary; decide whether legacy aggregate fields still need to
 be accepted; and define any image MIME validation, decoding, or payload-size
 policy at the server boundary before making the helper stable.
 
+## The ACP bridge kit (`@get-bb/plugin-sdk/provider-bridge/acp`)
+
+**What it does.** Publishes bb's generic Agent Client Protocol bridge so any
+plugin can add an ACP agent without bb-side code. `experimental_acpProviderBridge`
+is the bridge a plugin re-exports from its `bb.host` artifact; the agent to
+launch arrives per command in `providerOptions.acpLaunchSpec`, so one
+implementation serves every agent. `experimental_registerAcpDialect` and
+`experimental_resolveAcpDialect` are the dialect hooks: version 1 of the
+protocol has no sub-agent concept and standardizes nothing about `rawInput`,
+so each agent's vendor side channels (grok's `_meta["x.ai/tool"]`, Cursor's
+`cursor/task` request, an agent's own health/usage/installation surface) are
+read by a small profile-keyed module that a plugin can supply for its own
+agent and name in its registration's bridge options (`acpDialect`).
+`experimental_handleAcpBridgeLine` is the raw line handler for harnesses.
+`experimental_parseAcpAgentModelLines` / `experimental_buildAcpAgentModelCatalog`
+/ `experimental_splitAcpPrimaryModels` build a model picker from an agent's
+`--list-models` output. `experimental_acpProfileFromLaunchSpec` and
+`experimental_ACP_*` expose the launch profile and the protocol vocabularies.
+
+**Audit before stabilizing.** Decide whether `AcpDialect` is the right shape
+for a third-party agent — today it has four optional hooks (`toolIdentity`,
+`classifyToolCall`, `handleClientRequest`, `maintenance`) and no versioning,
+so adding a fifth is a silent capability change for every dialect. Decide
+whether `registerAcpDialect`'s process-global registry is right, or whether a
+dialect should be named by value in the provider registration instead of by
+id. Confirm the dialect id namespace (ids are unscoped strings today, so two
+plugins can collide) and whether a plugin may override a built-in dialect.
+Settle whether the bridge itself should be a factory rather than a module
+singleton before a host artifact ever needs two configured differently, and
+whether the model-catalog helpers belong in this kit at all or in a
+CLI-model-discovery kit of their own.
+
 ## Bridge record mode (`experimental_recordProviderChildIo` and `experimental_isProviderBridgeRecording`)
 
 **What it does.** `experimental_recordProviderChildIo` tees a provider
diff --git a/packages/plugin-build/src/builtin-host-artifacts.test.ts b/packages/plugin-build/src/builtin-host-artifacts.test.ts
index bfc6f49118..fc9dfe2293 100644
--- a/packages/plugin-build/src/builtin-host-artifacts.test.ts
+++ b/packages/plugin-build/src/builtin-host-artifacts.test.ts
@@ -7,6 +7,19 @@ import { resolvePluginBuildToolchain } from "./toolchain.js";
 
 const repositoryRoot = resolve(import.meta.dirname, "../../..");
 
+interface BuiltProviderBridge {
+  readonly experimental_apiVersion: 1;
+  readonly handleLine: (line: string) => void;
+}
+
+function isBuiltProviderBridge(value: unknown): value is BuiltProviderBridge {
+  if (typeof value !== "object" || value === null) return false;
+  return (
+    Reflect.get(value, "experimental_apiVersion") === 1 &&
+    typeof Reflect.get(value, "handleLine") === "function"
+  );
+}
+
 interface BuiltHostEntry {
   readonly experimental_apiVersion: 1;
   readonly handlers: Readonly<
@@ -78,4 +91,38 @@ describe("builtin host artifacts", () => {
       supported: process.platform === "darwin",
     });
   }, 20_000);
-});
+
+  /**
+   * The ACP plugin's whole host side is one re-export of the published kit
+   * (`@get-bb/plugin-sdk/provider-bridge/acp`), which is exactly what a
+   * third-party ACP plugin writes. This builds that artifact the way the
+   * daemon does — inlining the SDK's published bundle from the plugin's own
+   * node_modules — and imports the result, so a kit that only resolves
+   * through the workspace source condition cannot pass.
+   */
+  it("builds the ACP provider bridge from the published SDK subpath", async () => {
+    const root = await mkdtemp(join(repositoryRoot, ".builtin-host-test-"));
+    tempDirs.push(root);
+    const source = join(repositoryRoot, "plugins", "provider-acp");
+    for (const fileName of ["package.json", "server.ts"]) {
+      await cp(join(source, fileName), join(root, fileName));
+    }
+    await cp(join(source, "src"), join(root, "src"), { recursive: true });
+    // The manifest's branding icon must resolve for the build to run.
+    await cp(join(source, "icons"), join(root, "icons"), { recursive: true });
+    await symlink(
+      join(source, "node_modules"),
+      join(root, "node_modules"),
+      "dir",
+    );
+    const toolchain = await resolvePluginBuildToolchain(
+      join(repositoryRoot, "node_modules", ".unused-toolchain"),
+    );
+    const built = await buildPluginHost(root, "0.9.0-test", toolchain);
+    const imported: unknown = await import(
+      `${pathToFileURL(built.jsPath).href}?test=${Date.now()}`
+    );
+    const bridge = Reflect.get(Object(imported), "experimental_providerBridge");
+    expect(isBuiltProviderBridge(bridge)).toBe(true);
+  }, 60_000);
+});
\ No newline at end of file
diff --git a/packages/plugin-sdk/package.json b/packages/plugin-sdk/package.json
index dec2ece2ca..fb3d034087 100644
--- a/packages/plugin-sdk/package.json
+++ b/packages/plugin-sdk/package.json
@@ -38,6 +38,12 @@
       "import": "./dist/provider-bridge-testing.js",
       "default": "./dist/provider-bridge-testing.js"
     },
+    "./provider-bridge/acp": {
+      "source": "./src/provider-bridge-acp.ts",
+      "types": "./bundled-types/bb-plugin-sdk-provider-bridge-acp.d.ts",
+      "import": "./dist/provider-bridge-acp.js",
+      "default": "./dist/provider-bridge-acp.js"
+    },
     "./app": {
       "source": "./src/app.ts",
       "types": "./bundled-types/bb-plugin-sdk-app.d.ts",
@@ -113,6 +119,7 @@
     "@bb/domain": "workspace:*",
     "@bb/host-daemon-contract": "workspace:*",
     "@bb/process-utils": "workspace:*",
+    "@bb/provider-bridge-acp": "workspace:*",
     "@bb/provider-bridge-protocol": "workspace:*",
     "@bb/sdk": "workspace:*",
     "@bb/server-contract": "workspace:*",
diff --git a/packages/plugin-sdk/scripts/build-bundled-dts.mjs b/packages/plugin-sdk/scripts/build-bundled-dts.mjs
index bf78cb3a14..abd94f3d75 100644
--- a/packages/plugin-sdk/scripts/build-bundled-dts.mjs
+++ b/packages/plugin-sdk/scripts/build-bundled-dts.mjs
@@ -48,6 +48,10 @@ const outputs = {
     pkgRoot,
     "src/provider-bridge-testing.ts",
   ),
+  "bb-plugin-sdk-provider-bridge-acp.d.ts": path.join(
+    pkgRoot,
+    "src/provider-bridge-acp.ts",
+  ),
   "bb-plugin-sdk-host.d.ts": path.join(pkgRoot, "src/host.ts"),
   "bb-plugin-sdk-internal-composer-customization-validation.d.ts": path.join(
     pkgRoot,
diff --git a/packages/plugin-sdk/scripts/build-runtime.mjs b/packages/plugin-sdk/scripts/build-runtime.mjs
index e19a390d37..14519af141 100644
--- a/packages/plugin-sdk/scripts/build-runtime.mjs
+++ b/packages/plugin-sdk/scripts/build-runtime.mjs
@@ -28,6 +28,14 @@ const entries = [
     output: "dist/provider-bridge-testing.js",
     external: ["zod", "zod/*"],
   },
+  // The ACP kit: the generic Agent Client Protocol bridge a provider plugin
+  // re-exports from its host artifact, plus the dialect hooks. Real code, so
+  // only zod stays external.
+  {
+    source: "src/provider-bridge-acp.ts",
+    output: "dist/provider-bridge-acp.js",
+    external: ["zod", "zod/*"],
+  },
   { source: "src/host.ts", output: "dist/host.js", external: [] },
   {
     source: "src/internal/composer-customization-validation.ts",
diff --git a/packages/plugin-sdk/src/__tests__/package-exports.test.ts b/packages/plugin-sdk/src/__tests__/package-exports.test.ts
index 01d6b67ccf..dfba57a18b 100644
--- a/packages/plugin-sdk/src/__tests__/package-exports.test.ts
+++ b/packages/plugin-sdk/src/__tests__/package-exports.test.ts
@@ -25,6 +25,7 @@ describe("packed plugin SDK exports", () => {
       ".",
       "./provider-bridge",
       "./provider-bridge/testing",
+      "./provider-bridge/acp",
       "./app",
       "./host",
       "./internal/composer-customization-validation",
diff --git a/packages/plugin-sdk/src/provider-bridge-acp.ts b/packages/plugin-sdk/src/provider-bridge-acp.ts
new file mode 100644
index 0000000000..b5ad515fce
--- /dev/null
+++ b/packages/plugin-sdk/src/provider-bridge-acp.ts
@@ -0,0 +1,83 @@
+/**
+ * `@get-bb/plugin-sdk/provider-bridge/acp` — the published ACP bridge kit.
+ *
+ * The Agent Client Protocol (https://agentclientprotocol.com) is one wire
+ * protocol spoken by many agents, so bb runs all of them through one generic
+ * bridge: the agent to launch arrives per command in the provider options,
+ * and nothing in the bridge is bb-first-party. A plugin that wants to add an
+ * ACP agent re-exports the bridge from its `bb.host` artifact and registers
+ * its providers as any other plugin does:
+ *
+ * ```ts
+ * // host.ts (the plugin's `bb.host` entry)
+ * export { experimental_acpProviderBridge as experimental_providerBridge }
+ *   from "@get-bb/plugin-sdk/provider-bridge/acp";
+ *
+ * // server.ts
+ * bb.providers.register({
+ *   id: "amp",
+ *   displayName: "Amp",
+ *   experimental_bridgeOptions: {
+ *     acpLaunchSpec: { displayName: "Amp", command: "amp", args: ["acp"], env: {} },
+ *     acpDialect: "amp",
+ *   },
+ *   // …the rest of the declaration
+ * })
+ * ```
+ *
+ * **Dialects.** Version 1 of the protocol has no sub-agent concept and
+ * standardizes nothing about `rawInput`, so what most distinguishes one
+ * agent from another lives beside the protocol: grok stamps
+ * `_meta["x.ai/tool"]` on every tool event, Cursor reports sub-agents
+ * through a vendor `cursor/task` request. A dialect is a small module that
+ * reads those channels; a plugin registers one for its own agent with
+ * `experimental_registerAcpDialect` and names its id in the registration's
+ * bridge options. Everything a dialect does is optional — the shared
+ * classifier decides everything it declines.
+ *
+ * Curated by hand — named exports only, never `export *`. Value exports
+ * carry the `experimental_` prefix every new plugin API member ships with
+ * (see docs/api_to_audit.md); types are unprefixed.
+ */
+export {
+  acpProviderBridge as experimental_acpProviderBridge,
+  handleAcpBridgeLine as experimental_handleAcpBridgeLine,
+} from "@bb/provider-bridge-acp";
+
+export {
+  CURSOR_ACP_DIALECT as experimental_CURSOR_ACP_DIALECT,
+  GENERIC_ACP_DIALECT as experimental_GENERIC_ACP_DIALECT,
+  GROK_ACP_DIALECT as experimental_GROK_ACP_DIALECT,
+  acpDialectIds as experimental_acpDialectIds,
+  registerAcpDialect as experimental_registerAcpDialect,
+  resolveAcpDialect as experimental_resolveAcpDialect,
+} from "@bb/provider-bridge-acp";
+export type {
+  AcpClassifiedToolCall,
+  AcpClientRequestOutcome,
+  AcpDelegationReport,
+  AcpDialect,
+  AcpToolIdentity,
+} from "@bb/provider-bridge-acp";
+
+export { acpProfileFromLaunchSpec as experimental_acpProfileFromLaunchSpec } from "@bb/provider-bridge-acp";
+export type { AcpAgentProfile } from "@bb/provider-bridge-acp";
+
+export {
+  ACP_PROTOCOL_VERSION as experimental_ACP_PROTOCOL_VERSION,
+  ACP_TOOL_CALL_STATUSES as experimental_ACP_TOOL_CALL_STATUSES,
+  ACP_TOOL_KINDS as experimental_ACP_TOOL_KINDS,
+} from "@bb/provider-bridge-acp";
+export type {
+  AcpToolCallContent,
+  AcpToolCallStatus,
+  AcpToolCallUpdateEvent,
+  AcpToolKind,
+} from "@bb/provider-bridge-acp";
+
+export {
+  buildAgentModelCatalog as experimental_buildAcpAgentModelCatalog,
+  parseAgentModelLines as experimental_parseAcpAgentModelLines,
+  splitPrimaryModels as experimental_splitAcpPrimaryModels,
+} from "@bb/provider-bridge-acp";
+export type { AgentModelCatalog as AcpAgentModelCatalog } from "@bb/provider-bridge-acp";
diff --git a/packages/provider-bridge-acp/package.json b/packages/provider-bridge-acp/package.json
new file mode 100644
index 0000000000..f3d85ecea2
--- /dev/null
+++ b/packages/provider-bridge-acp/package.json
@@ -0,0 +1,33 @@
+{
+  "name": "@bb/provider-bridge-acp",
+  "version": "0.0.1",
+  "type": "module",
+  "exports": {
+    ".": {
+      "source": "./src/index.ts",
+      "types": "./src/index.ts",
+      "default": "./src/index.ts"
+    }
+  },
+  "types": "./src/index.ts",
+  "scripts": {
+    "clean": "rimraf dist tsconfig.tsbuildinfo",
+    "typecheck": "tsc --noEmit",
+    "test": "vitest run --config vitest.config.ts"
+  },
+  "dependencies": {
+    "@bb/domain": "workspace:*",
+    "@bb/host-daemon-contract": "workspace:*",
+    "@bb/process-utils": "workspace:*",
+    "@bb/provider-bridge-protocol": "workspace:*",
+    "zod": "^4.3.6"
+  },
+  "devDependencies": {
+    "@bb/tsconfig": "workspace:*",
+    "@modelcontextprotocol/sdk": "^1.29.0",
+    "@types/node": "^22.0.0",
+    "typescript": "npm:@typescript/typescript6@^6.0.2",
+    "typescript-7": "npm:typescript@^7.0.2",
+    "vitest": "^4.1.1"
+  }
+}
diff --git a/plugins/provider-acp/src/bridge-protocol.ts b/packages/provider-bridge-acp/src/bridge-protocol.ts
similarity index 87%
rename from plugins/provider-acp/src/bridge-protocol.ts
rename to packages/provider-bridge-acp/src/bridge-protocol.ts
index 0015de744c..ce3f54b5f5 100644
--- a/plugins/provider-acp/src/bridge-protocol.ts
+++ b/packages/provider-bridge-acp/src/bridge-protocol.ts
@@ -6,23 +6,8 @@
  * why they are schemas rather than ad-hoc objects.
  */
 
-import {
-  acpPermissionCliSchema as acpBridgePermissionCliSchema,
-  acpNativeReasoningSchema as acpBridgeNativeReasoningSchema,
-  acpReasoningCliSchema as acpBridgeReasoningCliSchema,
-  modelListParamsSchema as canonicalModelListParamsSchema,
-  threadDiscardParamsSchema as canonicalThreadDiscardParamsSchema,
-  threadForkParamsSchema as canonicalThreadForkParamsSchema,
-  threadResumeParamsSchema as canonicalThreadResumeParamsSchema,
-  threadStartParamsSchema as canonicalThreadStartParamsSchema,
-  threadStopParamsSchema as canonicalThreadStopParamsSchema,
-  turnStartParamsSchema as canonicalTurnStartParamsSchema,
-  turnSteerParamsSchema as canonicalTurnSteerParamsSchema,
-  skillsConfigureParamsSchema,
-  experimental_providerMaintenanceParamsSchema,
-  experimental_providerInstallationRunParamsSchema,
-  experimental_providerInstallationStatusParamsSchema,
-} from "@get-bb/plugin-sdk/provider-bridge";
+import { acpNativeReasoningSchema as acpBridgeNativeReasoningSchema, acpPermissionCliSchema as acpBridgePermissionCliSchema, acpReasoningCliSchema as acpBridgeReasoningCliSchema } from "@bb/domain";
+import { experimental_providerInstallationRunParamsSchema, experimental_providerInstallationStatusParamsSchema, experimental_providerMaintenanceParamsSchema, modelListParamsSchema as canonicalModelListParamsSchema, skillsConfigureParamsSchema, threadDiscardParamsSchema as canonicalThreadDiscardParamsSchema, threadForkParamsSchema as canonicalThreadForkParamsSchema, threadResumeParamsSchema as canonicalThreadResumeParamsSchema, threadStartParamsSchema as canonicalThreadStartParamsSchema, threadStopParamsSchema as canonicalThreadStopParamsSchema, turnStartParamsSchema as canonicalTurnStartParamsSchema, turnSteerParamsSchema as canonicalTurnSteerParamsSchema } from "@bb/provider-bridge-protocol";
 import { z } from "zod";
 import { acpSessionUpdateSchema, acpStopReasonSchema } from "./wire.js";
 
diff --git a/plugins/provider-acp/src/bridge/agent-connection.test.ts b/packages/provider-bridge-acp/src/bridge/agent-connection.test.ts
similarity index 100%
rename from plugins/provider-acp/src/bridge/agent-connection.test.ts
rename to packages/provider-bridge-acp/src/bridge/agent-connection.test.ts
diff --git a/plugins/provider-acp/src/bridge/agent-connection.ts b/packages/provider-bridge-acp/src/bridge/agent-connection.ts
similarity index 99%
rename from plugins/provider-acp/src/bridge/agent-connection.ts
rename to packages/provider-bridge-acp/src/bridge/agent-connection.ts
index 05255d430a..6ff85504c2 100644
--- a/plugins/provider-acp/src/bridge/agent-connection.ts
+++ b/packages/provider-bridge-acp/src/bridge/agent-connection.ts
@@ -8,7 +8,7 @@
 
 import { spawn, type ChildProcess } from "node:child_process";
 import { createInterface } from "node:readline";
-import { experimental_recordProviderChildIo } from "@get-bb/plugin-sdk/provider-bridge";
+import { experimental_recordProviderChildIo } from "@bb/provider-bridge-protocol/bridge-kit";
 import type { z } from "zod";
 
 const STDERR_TAIL_MAX_CHUNKS = 40;
diff --git a/plugins/provider-acp/src/bridge/bridge.conformance-calibration.test.ts b/packages/provider-bridge-acp/src/bridge/bridge.conformance-calibration.test.ts
similarity index 90%
rename from plugins/provider-acp/src/bridge/bridge.conformance-calibration.test.ts
rename to packages/provider-bridge-acp/src/bridge/bridge.conformance-calibration.test.ts
index fe24d8fc97..7dace77222 100644
--- a/plugins/provider-acp/src/bridge/bridge.conformance-calibration.test.ts
+++ b/packages/provider-bridge-acp/src/bridge/bridge.conformance-calibration.test.ts
@@ -4,16 +4,16 @@ import { dirname, join, resolve } from "node:path";
 import { fileURLToPath } from "node:url";
 import { afterEach, beforeEach, expect, it } from "vitest";
 import {
-  experimental_captureBridgeJsonRpcOutput as captureBridgeJsonRpcOutput,
-  experimental_createBridgeDeltaEventCollector as createBridgeDeltaEventCollector,
-  experimental_formatConformanceReport as formatConformanceReport,
-  experimental_runBridgeConformance as runBridgeConformance,
-  experimental_toConformanceMessages as toConformanceMessages,
-} from "@get-bb/plugin-sdk/provider-bridge/testing";
-import type {
-  BridgeConformanceTransport,
-  CapturedBridgeJsonRpcOutput,
-} from "@get-bb/plugin-sdk/provider-bridge/testing";
+  formatConformanceReport,
+  runBridgeConformance,
+} from "@bb/provider-bridge-protocol/conformance";
+import type { BridgeConformanceTransport } from "@bb/provider-bridge-protocol/conformance";
+import {
+  captureBridgeJsonRpcOutput,
+  createBridgeDeltaEventCollector,
+  toConformanceMessages,
+} from "@bb/provider-bridge-protocol/testing";
+import type { CapturedBridgeJsonRpcOutput } from "@bb/provider-bridge-protocol/testing";
 
 import { handleLine } from "./bridge.js";
 
diff --git a/plugins/provider-acp/src/bridge/bridge.recorded-conformance.test.ts b/packages/provider-bridge-acp/src/bridge/bridge.recorded-conformance.test.ts
similarity index 100%
rename from plugins/provider-acp/src/bridge/bridge.recorded-conformance.test.ts
rename to packages/provider-bridge-acp/src/bridge/bridge.recorded-conformance.test.ts
diff --git a/plugins/provider-acp/src/bridge/bridge.test.ts b/packages/provider-bridge-acp/src/bridge/bridge.test.ts
similarity index 99%
rename from plugins/provider-acp/src/bridge/bridge.test.ts
rename to packages/provider-bridge-acp/src/bridge/bridge.test.ts
index c3ad0e461e..7bd09d0755 100644
--- a/plugins/provider-acp/src/bridge/bridge.test.ts
+++ b/packages/provider-bridge-acp/src/bridge/bridge.test.ts
@@ -13,18 +13,15 @@ import { fileURLToPath } from "node:url";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { createStandaloneBuiltinCompactCommandInput } from "@bb/domain";
 import type { DynamicTool, ReasoningLevel } from "@bb/domain";
+import { PROVIDER_BRIDGE_PROTOCOL_VERSION, THREAD_DELTA_NOTIFICATION_METHOD } from "@bb/provider-bridge-protocol";
 import {
-  PROVIDER_BRIDGE_PROTOCOL_VERSION,
-  THREAD_DELTA_NOTIFICATION_METHOD,
-} from "@bb/provider-bridge-protocol";
-import {
-  experimental_assembleCapturedThreadEvents as assembleCapturedThreadEvents,
-  experimental_captureBridgeJsonRpcOutput as captureBridgeJsonRpcOutput,
-} from "@get-bb/plugin-sdk/provider-bridge/testing";
+  assembleCapturedThreadEvents,
+  captureBridgeJsonRpcOutput,
+} from "@bb/provider-bridge-protocol/testing";
 import type {
   BridgeJsonRpcOutputMessage,
   CapturedBridgeJsonRpcOutput,
-} from "@get-bb/plugin-sdk/provider-bridge/testing";
+} from "@bb/provider-bridge-protocol/testing";
 
 import { handleLine } from "./bridge.js";
 import { ACP_BRIDGE_NO_ACTIVE_TURN_ERROR_CODE } from "../bridge-protocol.js";
diff --git a/plugins/provider-acp/src/bridge/bridge.ts b/packages/provider-bridge-acp/src/bridge/bridge.ts
similarity index 97%
rename from plugins/provider-acp/src/bridge/bridge.ts
rename to packages/provider-bridge-acp/src/bridge/bridge.ts
index e7ee3a94c0..57c1f9ad69 100644
--- a/plugins/provider-acp/src/bridge/bridge.ts
+++ b/packages/provider-bridge-acp/src/bridge/bridge.ts
@@ -1,5 +1,3 @@
-#!/usr/bin/env node
-
 /**
  * Generic ACP bridge.
  *
@@ -11,33 +9,13 @@
  * workspace write policy on client `fs/write_text_file` requests.
  */
 
-import {
-  isStandaloneBuiltinCompactCommand,
-  pendingInteractionResolutionSchema,
-  reasoningEffortsForLevels,
-  type AvailableModel,
-  type PromptInput,
-  type ReasoningLevel,
-  type ThreadDelta,
-  hostDaemonAcpLaunchSpecSchema,
-  bridgeRequestEnvelopeSchema,
-  createBridgeIo,
-  createBridgeLineHandler,
-  decodeBridgeJsonRpcResponse,
-  decodeToolCallResponsePayload,
-  mimeTypeFromExtension,
-  runBridgeRequest,
-  withoutBridgeRuntimeEnv,
-  type BridgeJsonRpcResponse,
-  BRIDGE_INBOUND_REQUEST_METHODS,
-  BRIDGE_JSON_RPC_ERRORS,
-  BRIDGE_NOTIFICATION_METHODS,
-  PROVIDER_BRIDGE_PROTOCOL_VERSION,
-  THREAD_DELTA_GRAMMAR_V3,
-  THREAD_DELTA_NOTIFICATION_METHOD,
-  type InitializeResult,
-  experimental_defineProviderBridge,
-} from "@get-bb/plugin-sdk/provider-bridge";
+import { isStandaloneBuiltinCompactCommand, pendingInteractionResolutionSchema, reasoningEffortsForLevels } from "@bb/domain";
+import type { AvailableModel, PromptInput, ReasoningLevel } from "@bb/domain";
+import { hostDaemonAcpLaunchSpecSchema } from "@bb/host-daemon-contract";
+import { BRIDGE_INBOUND_REQUEST_METHODS, BRIDGE_JSON_RPC_ERRORS, BRIDGE_NOTIFICATION_METHODS, PROVIDER_BRIDGE_PROTOCOL_VERSION, THREAD_DELTA_GRAMMAR_V3, THREAD_DELTA_NOTIFICATION_METHOD } from "@bb/provider-bridge-protocol";
+import type { InitializeResult, ThreadDelta } from "@bb/provider-bridge-protocol";
+import { bridgeRequestEnvelopeSchema, createBridgeIo, createBridgeLineHandler, decodeBridgeJsonRpcResponse, decodeToolCallResponsePayload, experimental_defineProviderBridge, mimeTypeFromExtension, runBridgeRequest, withoutBridgeRuntimeEnv } from "@bb/provider-bridge-protocol/bridge-kit";
+import type { BridgeJsonRpcResponse } from "@bb/provider-bridge-protocol/bridge-kit";
 import { execFile } from "node:child_process";
 import { randomBytes } from "node:crypto";
 import { promises as fs, readFileSync } from "node:fs";
@@ -71,6 +49,7 @@ import {
   type AcpDeltaTranslator,
 } from "../delta-translation.js";
 import { resolveAcpDialect, type AcpDialect } from "../dialect.js";
+import type { AcpMaintenanceDialect } from "./provider-maintenance.js";
 import {
   buildAcpPermissionInteractionPayload,
   resolveAcpPermissionDecision,
@@ -2426,6 +2405,22 @@ function decodeDialectId(
   return acpProviderOptionsSchema.parse(providerOptions ?? {}).acpDialect;
 }
 
+/**
+ * The maintenance surface for a provider-maintenance request: the agent's
+ * dialect owns it, so the bridge never asks which bb provider is calling.
+ */
+function maintenanceForRequest(
+  providerOptions: Record<string, unknown> | undefined,
+): AcpMaintenanceDialect | undefined {
+  const profile = decodeLaunchProfile(providerOptions);
+  return resolveAcpDialect({
+    ...(decodeDialectId(providerOptions) === undefined
+      ? {}
+      : { dialectId: decodeDialectId(providerOptions) }),
+    command: profile?.agentCommand.command ?? "",
+  }).maintenance;
+}
+
 async function handleRequest(
   request: AcpBridgeCommand & { id: string | number },
 ): Promise<void> {
@@ -2485,7 +2480,7 @@ async function handleRequest(
       sendResult(
         request.id,
         await getAcpProviderHealth({
-          providerId: request.params.providerId,
+          maintenance: maintenanceForRequest(request.params.providerOptions),
           command: profile?.agentCommand.command ?? null,
         }),
       );
@@ -2497,7 +2492,7 @@ async function handleRequest(
       sendResult(
         request.id,
         await getAcpProviderUsage({
-          providerId: request.params.providerId,
+          maintenance: maintenanceForRequest(request.params.providerOptions),
           command: profile?.agentCommand.command ?? null,
         }),
       );
@@ -2509,7 +2504,7 @@ async function handleRequest(
       sendResult(
         request.id,
         await getAcpProviderInstallationStatus({
-          providerId: request.params.providerId,
+          maintenance: maintenanceForRequest(request.params.providerOptions),
           command: profile?.agentCommand.command ?? null,
         }),
       );
@@ -2521,7 +2516,7 @@ async function handleRequest(
       sendResult(
         request.id,
         await getAcpProviderInstallationRun({
-          providerId: request.params.providerId,
+          maintenance: maintenanceForRequest(request.params.providerOptions),
           command: profile?.agentCommand.command ?? null,
           action: request.params.action,
         }),
diff --git a/plugins/provider-acp/src/bridge/cursor-mcp-approval.test.ts b/packages/provider-bridge-acp/src/bridge/cursor-mcp-approval.test.ts
similarity index 100%
rename from plugins/provider-acp/src/bridge/cursor-mcp-approval.test.ts
rename to packages/provider-bridge-acp/src/bridge/cursor-mcp-approval.test.ts
diff --git a/plugins/provider-acp/src/bridge/cursor-mcp-approval.ts b/packages/provider-bridge-acp/src/bridge/cursor-mcp-approval.ts
similarity index 100%
rename from plugins/provider-acp/src/bridge/cursor-mcp-approval.ts
rename to packages/provider-bridge-acp/src/bridge/cursor-mcp-approval.ts
diff --git a/plugins/provider-acp/src/bridge/fake-acp-agent.mjs b/packages/provider-bridge-acp/src/bridge/fake-acp-agent.mjs
similarity index 100%
rename from plugins/provider-acp/src/bridge/fake-acp-agent.mjs
rename to packages/provider-bridge-acp/src/bridge/fake-acp-agent.mjs
diff --git a/plugins/provider-acp/src/bridge/mcp-server-entry.test.ts b/packages/provider-bridge-acp/src/bridge/mcp-server-entry.test.ts
similarity index 100%
rename from plugins/provider-acp/src/bridge/mcp-server-entry.test.ts
rename to packages/provider-bridge-acp/src/bridge/mcp-server-entry.test.ts
diff --git a/plugins/provider-acp/src/bridge/model-catalog.test.ts b/packages/provider-bridge-acp/src/bridge/model-catalog.test.ts
similarity index 100%
rename from plugins/provider-acp/src/bridge/model-catalog.test.ts
rename to packages/provider-bridge-acp/src/bridge/model-catalog.test.ts
diff --git a/plugins/provider-acp/src/bridge/model-catalog.ts b/packages/provider-bridge-acp/src/bridge/model-catalog.ts
similarity index 99%
rename from plugins/provider-acp/src/bridge/model-catalog.ts
rename to packages/provider-bridge-acp/src/bridge/model-catalog.ts
index 8f3a11ce65..a3a1de8f1f 100644
--- a/plugins/provider-acp/src/bridge/model-catalog.ts
+++ b/packages/provider-bridge-acp/src/bridge/model-catalog.ts
@@ -31,12 +31,8 @@
  * marker, and Cursor's own `(default)`/`(current)` annotations.
  */
 
-import {
-  reasoningLevelValues,
-  type AvailableModel,
-  type ReasoningLevel,
-  type ServiceTier,
-} from "@get-bb/plugin-sdk/provider-bridge";
+import { reasoningLevelValues } from "@bb/domain";
+import type { AvailableModel, ReasoningLevel, ServiceTier } from "@bb/domain";
 import type { AcpConfigOption, AcpSessionModels } from "../wire.js";
 
 interface RawAgentModel {
diff --git a/plugins/provider-acp/src/bridge/provider-maintenance.test.ts b/packages/provider-bridge-acp/src/bridge/provider-maintenance.test.ts
similarity index 66%
rename from plugins/provider-acp/src/bridge/provider-maintenance.test.ts
rename to packages/provider-bridge-acp/src/bridge/provider-maintenance.test.ts
index 5140caf153..c7d9c0dc29 100644
--- a/plugins/provider-acp/src/bridge/provider-maintenance.test.ts
+++ b/packages/provider-bridge-acp/src/bridge/provider-maintenance.test.ts
@@ -1,5 +1,8 @@
 import { describe, expect, it } from "vitest";
-import { __testing } from "./provider-maintenance.js";
+import {
+  CURSOR_ACP_MAINTENANCE,
+  __testing,
+} from "./provider-maintenance.js";
 
 function cursorMissingInstallationStatus() {
   return {
@@ -57,11 +60,18 @@ describe("ACP provider maintenance", () => {
     });
   });
 
-  it("offers the Cursor installer only through a fresh matching action", () => {
+  // The installer belongs to the agent's dialect, not to a bb provider id:
+  // an agent whose dialect has no maintenance surface offers none, whatever
+  // it is registered as.
+  it("offers the installer only through a fresh matching action", () => {
     expect(
       __testing.buildProviderInstallationRun(
         cursorMissingInstallationStatus(),
-        { providerId: "acp-cursor", action: "install" },
+        {
+          maintenance: CURSOR_ACP_MAINTENANCE,
+          command: "cursor-agent",
+          action: "install",
+        },
       ),
     ).toMatchObject({
       available: true,
@@ -71,11 +81,22 @@ describe("ACP provider maintenance", () => {
     expect(
       __testing.buildProviderInstallationRun(
         { ...cursorMissingInstallationStatus(), installAction: null },
-        { providerId: "acp-opencode", action: "install" },
+        { maintenance: undefined, command: "opencode", action: "install" },
       ),
     ).toEqual({
       available: false,
-      message: "acp-opencode install is not available on this host.",
+      message: "opencode install is not available on this host.",
+    });
+    // A matching action with no maintenance surface still declines.
+    expect(
+      __testing.buildProviderInstallationRun(cursorMissingInstallationStatus(), {
+        maintenance: undefined,
+        command: "opencode",
+        action: "install",
+      }),
+    ).toEqual({
+      available: false,
+      message: "opencode install is not available on this host.",
     });
   });
 });
diff --git a/plugins/provider-acp/src/bridge/provider-maintenance.ts b/packages/provider-bridge-acp/src/bridge/provider-maintenance.ts
similarity index 80%
rename from plugins/provider-acp/src/bridge/provider-maintenance.ts
rename to packages/provider-bridge-acp/src/bridge/provider-maintenance.ts
index afcc3e2d20..ef2119a783 100644
--- a/plugins/provider-acp/src/bridge/provider-maintenance.ts
+++ b/packages/provider-bridge-acp/src/bridge/provider-maintenance.ts
@@ -5,20 +5,12 @@ import os from "node:os";
 import path from "node:path";
 import { DatabaseSync } from "node:sqlite";
 import { promisify } from "node:util";
-import type {
-  ExperimentalProviderHealthResult,
-  ExperimentalProviderInstallationRunResult,
-  ExperimentalProviderInstallationStatus,
-  ExperimentalProviderUsage,
-  ExperimentalProviderUsageResult,
-  ExperimentalProviderUsageWindow,
-} from "@get-bb/plugin-sdk/provider-bridge";
+import type { ExperimentalProviderHealthResult, ExperimentalProviderInstallationRunResult, ExperimentalProviderInstallationStatus, ExperimentalProviderUsage, ExperimentalProviderUsageResult, ExperimentalProviderUsageWindow } from "@bb/provider-bridge-protocol";
 import { z } from "zod";
 
 const execFileAsync = promisify(execFile);
 const COMMAND_TIMEOUT_MS = 5_000;
 const USAGE_FETCH_TIMEOUT_MS = 15_000;
-const CURSOR_PROVIDER_ID = "acp-cursor";
 const CURSOR_DASHBOARD_URL =
   "https://api2.cursor.sh/aiserver.v1.DashboardService";
 const CURSOR_KEYCHAIN_ACCOUNT = "cursor-user";
@@ -155,14 +147,32 @@ function readAccountEmail(): string | null {
   }
 }
 
+/**
+ * What an agent's own dialect knows about keeping it healthy: how a user
+ * signs in, whether bb can install it, and where its account and usage live.
+ * ACP standardizes none of it, so a generic bridge can only report whether
+ * the executable exists — everything richer belongs to the agent, and is
+ * therefore the dialect's (see `dialect.ts`), never a bb provider id's.
+ */
+export interface AcpMaintenanceDialect {
+  /** The shell command that signs the user in. */
+  loginCommand: string;
+  /** How bb installs or updates the agent, when it can. */
+  installer(): { command: string; args: string[]; displayCommand: string };
+  /** The signed-in account, or null when the agent is not signed in. */
+  readAccount(): Promise<{ email: string | null } | null>;
+  /** The agent's usage windows, for the usage surfaces. */
+  readUsage(): Promise<ExperimentalProviderUsageResult>;
+}
+
 function healthResult(args: {
-  providerId: string;
+  maintenance: AcpMaintenanceDialect | undefined;
   status: "ready" | "not_installed" | "unauthenticated" | "unknown";
   accountEmail?: string | null;
   installedVersion?: string | null;
   statusMessage?: string | null;
 }): ExperimentalProviderHealthResult {
-  const cursor = args.providerId === CURSOR_PROVIDER_ID;
+  const maintained = args.maintenance !== undefined;
   return {
     supported: true,
     health: {
@@ -172,49 +182,47 @@ function healthResult(args: {
       planLabel: null,
       installedVersion: args.installedVersion ?? null,
       minimumSupportedVersion: null,
-      canInstall: cursor,
-      canUpdate: cursor && args.status !== "not_installed",
-      loginCommand: cursor ? "cursor-agent login" : null,
+      canInstall: maintained,
+      canUpdate: maintained && args.status !== "not_installed",
+      loginCommand: args.maintenance?.loginCommand ?? null,
     },
   };
 }
 
 export async function getAcpProviderHealth(args: {
-  providerId: string;
+  maintenance: AcpMaintenanceDialect | undefined;
   command: string | null;
 }): Promise<ExperimentalProviderHealthResult> {
+  const maintenance = args.maintenance;
   if (args.command === null) {
     return healthResult({
-      providerId: args.providerId,
+      maintenance,
       status: "unknown",
       statusMessage: "The ACP provider has no launch command.",
     });
   }
   if ((await executablePath(args.command)) === null) {
-    return healthResult({
-      providerId: args.providerId,
-      status: "not_installed",
-    });
+    return healthResult({ maintenance, status: "not_installed" });
   }
   const version = await installedVersion(args.command);
-  if (args.providerId !== CURSOR_PROVIDER_ID) {
+  if (maintenance === undefined) {
     return healthResult({
-      providerId: args.providerId,
+      maintenance,
       status: "ready",
       installedVersion: version,
     });
   }
   try {
-    const accessToken = await readAccessToken();
+    const account = await maintenance.readAccount();
     return healthResult({
-      providerId: args.providerId,
-      status: accessToken === null ? "unauthenticated" : "ready",
-      accountEmail: accessToken === null ? null : readAccountEmail(),
+      maintenance,
+      status: account === null ? "unauthenticated" : "ready",
+      accountEmail: account?.email ?? null,
       installedVersion: version,
     });
   } catch (error) {
     return healthResult({
-      providerId: args.providerId,
+      maintenance,
       status: "unknown",
       installedVersion: version,
       statusMessage: error instanceof Error ? error.message : String(error),
@@ -237,10 +245,10 @@ function cursorInstallerCommand(): {
 }
 
 export async function getAcpProviderInstallationStatus(args: {
-  providerId: string;
+  maintenance: AcpMaintenanceDialect | undefined;
   command: string | null;
 }): Promise<ExperimentalProviderInstallationStatus> {
-  const executableName = args.command ?? "cursor-agent";
+  const executableName = args.command ?? "";
   const resolvedExecutable =
     args.command === null ? null : await executablePath(args.command);
   const installed = resolvedExecutable !== null;
@@ -249,11 +257,11 @@ export async function getAcpProviderInstallationStatus(args: {
       ? await installedVersion(args.command)
       : null;
   const installAction =
-    args.providerId === CURSOR_PROVIDER_ID && !installed
+    args.maintenance !== undefined && !installed
       ? {
           kind: "install" as const,
           label: "Install" as const,
-          command: cursorInstallerCommand().displayCommand,
+          command: args.maintenance.installer().displayCommand,
         }
       : null;
   return {
@@ -273,7 +281,7 @@ export async function getAcpProviderInstallationStatus(args: {
 }
 
 export async function getAcpProviderInstallationRun(args: {
-  providerId: string;
+  maintenance: AcpMaintenanceDialect | undefined;
   command: string | null;
   action: "install" | "update";
 }): Promise<ExperimentalProviderInstallationRunResult> {
@@ -283,17 +291,21 @@ export async function getAcpProviderInstallationRun(args: {
 
 function buildAcpProviderInstallationRun(
   status: ExperimentalProviderInstallationStatus,
-  args: { providerId: string; action: "install" | "update" },
+  args: {
+    maintenance: AcpMaintenanceDialect | undefined;
+    command: string | null;
+    action: "install" | "update";
+  },
 ): ExperimentalProviderInstallationRunResult {
-  if (status.installAction?.kind !== args.action) {
+  if (status.installAction?.kind !== args.action || args.maintenance === undefined) {
     return {
       available: false,
-      message: `${args.providerId} ${args.action} is not available on this host.`,
+      message: `${args.command ?? "This ACP agent"} ${args.action} is not available on this host.`,
     };
   }
   return {
     available: true,
-    command: cursorInstallerCommand(),
+    command: args.maintenance.installer(),
     verification: { kind: "installed" },
   };
 }
@@ -409,13 +421,28 @@ function fetchDashboard(
 }
 
 export async function getAcpProviderUsage(args: {
-  providerId: string;
+  maintenance: AcpMaintenanceDialect | undefined;
   command: string | null;
 }): Promise<ExperimentalProviderUsageResult> {
-  if (args.providerId !== CURSOR_PROVIDER_ID) return { supported: false };
+  if (args.maintenance === undefined) return { supported: false };
   if (args.command === null || (await executablePath(args.command)) === null) {
     return { supported: true, usage: { status: "not_installed" } };
   }
+  return args.maintenance.readUsage();
+}
+
+/** Cursor's own maintenance surface; the cursor dialect carries it. */
+export const CURSOR_ACP_MAINTENANCE: AcpMaintenanceDialect = {
+  loginCommand: "cursor-agent login",
+  installer: cursorInstallerCommand,
+  readAccount: async () => {
+    const accessToken = await readAccessToken();
+    return accessToken === null ? null : { email: readAccountEmail() };
+  },
+  readUsage: readCursorUsage,
+};
+
+async function readCursorUsage(): Promise<ExperimentalProviderUsageResult> {
   const accessToken = await readAccessToken();
   if (!accessToken) {
     return { supported: true, usage: { status: "unauthenticated" } };
diff --git a/plugins/provider-acp/src/bridge/tool-proxy-mcp.test.ts b/packages/provider-bridge-acp/src/bridge/tool-proxy-mcp.test.ts
similarity index 100%
rename from plugins/provider-acp/src/bridge/tool-proxy-mcp.test.ts
rename to packages/provider-bridge-acp/src/bridge/tool-proxy-mcp.test.ts
diff --git a/plugins/provider-acp/src/bridge/tool-proxy-mcp.ts b/packages/provider-bridge-acp/src/bridge/tool-proxy-mcp.ts
similarity index 97%
rename from plugins/provider-acp/src/bridge/tool-proxy-mcp.ts
rename to packages/provider-bridge-acp/src/bridge/tool-proxy-mcp.ts
index d95fdcd8a6..dea0615c5a 100644
--- a/plugins/provider-acp/src/bridge/tool-proxy-mcp.ts
+++ b/packages/provider-bridge-acp/src/bridge/tool-proxy-mcp.ts
@@ -1,8 +1,6 @@
-import {
-  dynamicToolSchema,
-  experimental_buildBridgeToolCallContent,
-  type DynamicTool,
-} from "@get-bb/plugin-sdk/provider-bridge";
+import { dynamicToolSchema } from "@bb/domain";
+import type { DynamicTool } from "@bb/domain";
+import { buildBridgeToolCallContent as experimental_buildBridgeToolCallContent } from "@bb/provider-bridge-protocol/bridge-kit";
 import { createConnection } from "node:net";
 import { createInterface } from "node:readline";
 import { z } from "zod";
diff --git a/plugins/provider-acp/src/delta-translation.test.ts b/packages/provider-bridge-acp/src/delta-translation.test.ts
similarity index 99%
rename from plugins/provider-acp/src/delta-translation.test.ts
rename to packages/provider-bridge-acp/src/delta-translation.test.ts
index 4052baf951..a49eaf924b 100644
--- a/plugins/provider-acp/src/delta-translation.test.ts
+++ b/packages/provider-bridge-acp/src/delta-translation.test.ts
@@ -1,8 +1,8 @@
 import { describe, expect, it } from "vitest";
 import { threadScope, turnScope, type ThreadEvent } from "@bb/domain";
 import type { ProviderRuntimeEvent } from "@bb/provider-bridge-protocol/bridge-kit";
-import { experimental_createDeltaAssembler as createDeltaAssembler } from "@get-bb/plugin-sdk/provider-bridge/testing";
-import type { DeltaAssembler } from "@get-bb/plugin-sdk/provider-bridge/testing";
+import { createDeltaAssembler } from "@bb/provider-bridge-protocol/assembler";
+import type { DeltaAssembler } from "@bb/provider-bridge-protocol/assembler";
 import {
   ACP_COMPACTION_COMPLETED_METHOD,
   ACP_COMPACTION_STARTED_METHOD,
diff --git a/plugins/provider-acp/src/delta-translation.ts b/packages/provider-bridge-acp/src/delta-translation.ts
similarity index 98%
rename from plugins/provider-acp/src/delta-translation.ts
rename to packages/provider-bridge-acp/src/delta-translation.ts
index b53425d8aa..f11035be54 100644
--- a/plugins/provider-acp/src/delta-translation.ts
+++ b/packages/provider-bridge-acp/src/delta-translation.ts
@@ -15,22 +15,12 @@
  * in the assembler.
  */
 
-import {
-  errorEnvelopeSchema,
-  jsonRpcEnvelopeSchema,
-  providerRawEventSchema,
-  type JsonRpcMessage,
-  type ProviderRawEvent,
-  type ProviderRuntimeEvent,
-} from "@get-bb/plugin-sdk/provider-bridge";
-import type {
-  DeltaItemShape,
-  DeltaNoTurnFallback,
-  ThreadDelta,
-  ThreadEventItemStatus,
-  ThreadEventPlanStep,
-  ThreadEventTurnStatus,
-} from "@get-bb/plugin-sdk/provider-bridge";
+import { providerRawEventSchema } from "@bb/domain";
+import type { ProviderRawEvent } from "@bb/domain";
+import { errorEnvelopeSchema, jsonRpcEnvelopeSchema } from "@bb/provider-bridge-protocol/bridge-kit";
+import type { JsonRpcMessage, ProviderRuntimeEvent } from "@bb/provider-bridge-protocol/bridge-kit";
+import type { ThreadEventItemStatus, ThreadEventPlanStep, ThreadEventTurnStatus } from "@bb/domain";
+import type { DeltaItemShape, DeltaNoTurnFallback, ThreadDelta } from "@bb/provider-bridge-protocol";
 import {
   ACP_COMPACTION_COMPLETED_METHOD,
   ACP_COMPACTION_STARTED_METHOD,
diff --git a/plugins/provider-acp/src/dialect.test.ts b/packages/provider-bridge-acp/src/dialect.test.ts
similarity index 100%
rename from plugins/provider-acp/src/dialect.test.ts
rename to packages/provider-bridge-acp/src/dialect.test.ts
diff --git a/plugins/provider-acp/src/dialect.ts b/packages/provider-bridge-acp/src/dialect.ts
similarity index 86%
rename from plugins/provider-acp/src/dialect.ts
rename to packages/provider-bridge-acp/src/dialect.ts
index e082da02da..2dff929e83 100644
--- a/plugins/provider-acp/src/dialect.ts
+++ b/packages/provider-bridge-acp/src/dialect.ts
@@ -18,9 +18,13 @@
  * nothing and leaves every decision to the protocol fields.
  */
 
-import type { DeltaItemShape } from "@get-bb/plugin-sdk/provider-bridge";
+import type { DeltaItemShape } from "@bb/provider-bridge-protocol";
 import { basename } from "node:path";
 import { z } from "zod";
+import {
+  CURSOR_ACP_MAINTENANCE,
+  type AcpMaintenanceDialect,
+} from "./bridge/provider-maintenance.js";
 import { delegationPresentation } from "./presentation.js";
 import type { AcpClassifiedToolCall } from "./tool-classification.js";
 import {
@@ -80,6 +84,12 @@ export interface AcpDialect {
     method: string,
     params: unknown,
   ): AcpClientRequestOutcome | undefined;
+  /**
+   * How bb keeps this agent healthy: sign-in, installation, account and
+   * usage. ACP standardizes none of it, so an agent without one reports only
+   * whether its executable exists.
+   */
+  maintenance?: AcpMaintenanceDialect;
 }
 
 export interface AcpClientRequestOutcome {
@@ -266,17 +276,34 @@ export const CURSOR_ACP_DIALECT: AcpDialect = {
   id: "cursor",
   classifyToolCall: cursorClassifyToolCall,
   handleClientRequest: cursorHandleClientRequest,
+  maintenance: CURSOR_ACP_MAINTENANCE,
 };
 
 // ---------------------------------------------------------------------------
 // Selection
 // ---------------------------------------------------------------------------
 
-/** Every dialect this kit ships, by id. */
-const DIALECTS_BY_ID: Readonly<Record<string, AcpDialect>> = {
-  [CURSOR_ACP_DIALECT.id]: CURSOR_ACP_DIALECT,
-  [GROK_ACP_DIALECT.id]: GROK_ACP_DIALECT,
-};
+/**
+ * Every dialect the bridge can select, by id: the ones this kit ships plus
+ * any a plugin registered. A plugin registers its own from the module scope
+ * of its `bb.host` artifact, which the bridge shares, before any session
+ * starts.
+ */
+const DIALECTS_BY_ID = new Map<string, AcpDialect>([
+  [CURSOR_ACP_DIALECT.id, CURSOR_ACP_DIALECT],
+  [GROK_ACP_DIALECT.id, GROK_ACP_DIALECT],
+]);
+
+/**
+ * Teach the bridge one agent's side channels. A plugin that registers an ACP
+ * agent bb has never seen — Amp, or an in-house agent — ships a dialect for
+ * it and names the id in its provider registration's bridge options
+ * (`acpDialect`). Registering an id twice replaces the earlier dialect, so a
+ * plugin can override a built-in for its own registration.
+ */
+export function registerAcpDialect(dialect: AcpDialect): void {
+  DIALECTS_BY_ID.set(dialect.id, dialect);
+}
 
 /** The executable name each dialect's agent is normally launched as. */
 const DIALECT_IDS_BY_COMMAND: Readonly<Record<string, string>> = {
@@ -284,8 +311,10 @@ const DIALECT_IDS_BY_COMMAND: Readonly<Record<string, string>> = {
   grok: GROK_ACP_DIALECT.id,
 };
 
-/** Every dialect id a profile may name. */
-export const ACP_DIALECT_IDS = Object.keys(DIALECTS_BY_ID);
+/** Every dialect id a profile may name, registered ones included. */
+export function acpDialectIds(): string[] {
+  return [...DIALECTS_BY_ID.keys()];
+}
 
 /**
  * The dialect for an agent launch. The profile names it (the ACP plugin puts
@@ -304,10 +333,10 @@ export function resolveAcpDialect(launch: {
   command: string;
 }): AcpDialect {
   if (launch.dialectId !== undefined) {
-    return DIALECTS_BY_ID[launch.dialectId] ?? GENERIC_ACP_DIALECT;
+    return DIALECTS_BY_ID.get(launch.dialectId) ?? GENERIC_ACP_DIALECT;
   }
   const byCommand = DIALECT_IDS_BY_COMMAND[basename(launch.command)];
   return byCommand === undefined
     ? GENERIC_ACP_DIALECT
-    : (DIALECTS_BY_ID[byCommand] ?? GENERIC_ACP_DIALECT);
+    : (DIALECTS_BY_ID.get(byCommand) ?? GENERIC_ACP_DIALECT);
 }
diff --git a/packages/provider-bridge-acp/src/index.ts b/packages/provider-bridge-acp/src/index.ts
new file mode 100644
index 0000000000..02251658c4
--- /dev/null
+++ b/packages/provider-bridge-acp/src/index.ts
@@ -0,0 +1,60 @@
+/**
+ * The ACP provider-bridge kit.
+ *
+ * bb runs Cursor, grok and every other Agent Client Protocol agent through
+ * one generic bridge: it speaks bb's runtime JSON-RPC on stdio, acts as the
+ * ACP *client* for the agent it launches, and translates the agent's session
+ * updates into bb's thread-delta grammar. Nothing in it is bb-first-party —
+ * the agent to launch arrives per command in the provider options — so the
+ * same bridge serves a plugin bb has never heard of.
+ *
+ * This barrel is what `@get-bb/plugin-sdk/provider-bridge/acp` publishes.
+ * The plugin that owns an ACP agent needs three things from it: the bridge
+ * to re-export from its `bb.host` artifact, the dialect hooks to describe
+ * its agent's vendor side channels, and the profile type its registration
+ * fills in.
+ */
+
+export {
+  experimental_providerBridge as acpProviderBridge,
+  handleLine as handleAcpBridgeLine,
+} from "./bridge/bridge.js";
+
+export {
+  CURSOR_ACP_DIALECT,
+  GENERIC_ACP_DIALECT,
+  GROK_ACP_DIALECT,
+  acpDialectIds,
+  registerAcpDialect,
+  resolveAcpDialect,
+} from "./dialect.js";
+export type {
+  AcpClientRequestOutcome,
+  AcpDelegationReport,
+  AcpDialect,
+  AcpToolIdentity,
+} from "./dialect.js";
+
+export type { AcpAgentProfile } from "./profiles.js";
+export { acpProfileFromLaunchSpec } from "./profiles.js";
+
+export type { AcpClassifiedToolCall } from "./tool-classification.js";
+
+export {
+  ACP_PROTOCOL_VERSION,
+  ACP_TOOL_CALL_STATUSES,
+  ACP_TOOL_KINDS,
+} from "./wire.js";
+export type {
+  AcpToolCallContent,
+  AcpToolCallStatus,
+  AcpToolCallUpdateEvent,
+  AcpToolKind,
+} from "./wire.js";
+
+export {
+  buildAgentModelCatalog,
+  parseAgentModelLines,
+  splitPrimaryModels,
+} from "./bridge/model-catalog.js";
+export type { AgentModelCatalog } from "./bridge/model-catalog.js";
diff --git a/plugins/provider-acp/src/interactions.test.ts b/packages/provider-bridge-acp/src/interactions.test.ts
similarity index 100%
rename from plugins/provider-acp/src/interactions.test.ts
rename to packages/provider-bridge-acp/src/interactions.test.ts
diff --git a/plugins/provider-acp/src/interactions.ts b/packages/provider-bridge-acp/src/interactions.ts
similarity index 96%
rename from plugins/provider-acp/src/interactions.ts
rename to packages/provider-bridge-acp/src/interactions.ts
index 448e016fe5..db612add8b 100644
--- a/plugins/provider-acp/src/interactions.ts
+++ b/packages/provider-bridge-acp/src/interactions.ts
@@ -9,14 +9,8 @@
  * subject carrying the same presentation its timeline row does.
  */
 
-import {
-  type PendingInteractionApprovalDecision,
-  type PendingInteractionApprovalSubject,
-  type PendingInteractionPayload,
-  type PendingInteractionResolution,
-  isApprovalPendingInteractionPayload,
-  isApprovalPendingInteractionResolution,
-} from "@get-bb/plugin-sdk/provider-bridge";
+import { isApprovalPendingInteractionPayload, isApprovalPendingInteractionResolution } from "@bb/domain";
+import type { PendingInteractionApprovalDecision, PendingInteractionApprovalSubject, PendingInteractionPayload, PendingInteractionResolution } from "@bb/domain";
 import { toolKindPresentation } from "./presentation.js";
 import {
   type AcpToolCallOperation,
diff --git a/plugins/provider-acp/src/presentation.ts b/packages/provider-bridge-acp/src/presentation.ts
similarity index 99%
rename from plugins/provider-acp/src/presentation.ts
rename to packages/provider-bridge-acp/src/presentation.ts
index 23f85b4d6e..f766118be5 100644
--- a/plugins/provider-acp/src/presentation.ts
+++ b/packages/provider-bridge-acp/src/presentation.ts
@@ -13,7 +13,7 @@
  * Icons are host glyph names from the shared icon registry
  * (`@bb/shared-ui/icon`); the persisted form is glyph-only by design.
  */
-import type { DeltaPresentation } from "@get-bb/plugin-sdk/provider-bridge";
+import type { DeltaPresentation } from "@bb/provider-bridge-protocol";
 import type { AcpToolKind } from "./wire.js";
 
 /** Row headlines stay one line and short; the item carries the full text. */
diff --git a/plugins/provider-acp/src/profiles.ts b/packages/provider-bridge-acp/src/profiles.ts
similarity index 90%
rename from plugins/provider-acp/src/profiles.ts
rename to packages/provider-bridge-acp/src/profiles.ts
index 2b61a1e853..61f5e218fe 100644
--- a/plugins/provider-acp/src/profiles.ts
+++ b/packages/provider-bridge-acp/src/profiles.ts
@@ -1,7 +1,5 @@
-import {
-  normalizeHostDaemonAcpLaunchSpec,
-  type HostDaemonAcpLaunchSpec,
-} from "@get-bb/plugin-sdk/provider-bridge";
+import { normalizeHostDaemonAcpLaunchSpec } from "@bb/host-daemon-contract";
+import type { HostDaemonAcpLaunchSpec } from "@bb/host-daemon-contract";
 
 /**
  * CLI model surface of the agent's launch binary: how to discover models and
diff --git a/plugins/provider-acp/src/session-params.test.ts b/packages/provider-bridge-acp/src/session-params.test.ts
similarity index 100%
rename from plugins/provider-acp/src/session-params.test.ts
rename to packages/provider-bridge-acp/src/session-params.test.ts
diff --git a/plugins/provider-acp/src/session-params.ts b/packages/provider-bridge-acp/src/session-params.ts
similarity index 98%
rename from plugins/provider-acp/src/session-params.ts
rename to packages/provider-bridge-acp/src/session-params.ts
index 59e6eaa319..57669812cf 100644
--- a/plugins/provider-acp/src/session-params.ts
+++ b/packages/provider-bridge-acp/src/session-params.ts
@@ -4,12 +4,7 @@
  * model-list params out.
  */
 
-import {
-  type DynamicTool,
-  type PermissionMode,
-  type ReasoningLevel,
-  type ServiceTier,
-} from "@get-bb/plugin-sdk/provider-bridge";
+import type { DynamicTool, PermissionMode, ReasoningLevel, ServiceTier } from "@bb/domain";
 import path from "node:path";
 
 import { ACP_DEFAULT_MODEL_ID } from "./bridge-protocol.js";
diff --git a/plugins/provider-acp/src/tool-call-operation.test.ts b/packages/provider-bridge-acp/src/tool-call-operation.test.ts
similarity index 100%
rename from plugins/provider-acp/src/tool-call-operation.test.ts
rename to packages/provider-bridge-acp/src/tool-call-operation.test.ts
diff --git a/plugins/provider-acp/src/tool-call-operation.ts b/packages/provider-bridge-acp/src/tool-call-operation.ts
similarity index 98%
rename from plugins/provider-acp/src/tool-call-operation.ts
rename to packages/provider-bridge-acp/src/tool-call-operation.ts
index 0457018d45..be83148908 100644
--- a/plugins/provider-acp/src/tool-call-operation.ts
+++ b/packages/provider-bridge-acp/src/tool-call-operation.ts
@@ -9,7 +9,7 @@
  */
 
 import path from "node:path";
-import { toOptionalString } from "@get-bb/plugin-sdk/provider-bridge";
+import { toOptionalString } from "@bb/provider-bridge-protocol/bridge-kit";
 import { z } from "zod";
 import type { AcpToolCallContent } from "./wire.js";
 
diff --git a/plugins/provider-acp/src/tool-classification.ts b/packages/provider-bridge-acp/src/tool-classification.ts
similarity index 98%
rename from plugins/provider-acp/src/tool-classification.ts
rename to packages/provider-bridge-acp/src/tool-classification.ts
index 7c868ce59e..6be81732cf 100644
--- a/plugins/provider-acp/src/tool-classification.ts
+++ b/packages/provider-bridge-acp/src/tool-classification.ts
@@ -20,13 +20,8 @@
  * disagree (#1803).
  */
 
-import {
-  extractResultText,
-  toOptionalString,
-  type DeltaFileChange,
-  type DeltaItemShape,
-  type DeltaPresentation,
-} from "@get-bb/plugin-sdk/provider-bridge";
+import type { DeltaFileChange, DeltaItemShape, DeltaPresentation } from "@bb/provider-bridge-protocol";
+import { extractResultText, toOptionalString } from "@bb/provider-bridge-protocol/bridge-kit";
 import { z } from "zod";
 import {
   bbToolPresentation,
diff --git a/plugins/provider-acp/src/visibility.ts b/packages/provider-bridge-acp/src/visibility.ts
similarity index 91%
rename from plugins/provider-acp/src/visibility.ts
rename to packages/provider-bridge-acp/src/visibility.ts
index d6903766cc..1fedd5171e 100644
--- a/plugins/provider-acp/src/visibility.ts
+++ b/packages/provider-bridge-acp/src/visibility.ts
@@ -1,11 +1,5 @@
-import {
-  createProviderVisibilityMetadata,
-  getStringProperty,
-  isRecord,
-  type JsonRpcMessage,
-  type ProviderRawEventDescription,
-  type ProviderVisibilityMetadata,
-} from "@get-bb/plugin-sdk/provider-bridge";
+import { createProviderVisibilityMetadata, getStringProperty, isRecord } from "@bb/provider-bridge-protocol/bridge-kit";
+import type { JsonRpcMessage, ProviderRawEventDescription, ProviderVisibilityMetadata } from "@bb/provider-bridge-protocol/bridge-kit";
 import {
   ACP_FS_WRITE_METHOD,
   ACP_TURN_COMPLETED_METHOD,
diff --git a/plugins/provider-acp/src/wire.test.ts b/packages/provider-bridge-acp/src/wire.test.ts
similarity index 100%
rename from plugins/provider-acp/src/wire.test.ts
rename to packages/provider-bridge-acp/src/wire.test.ts
diff --git a/plugins/provider-acp/src/wire.ts b/packages/provider-bridge-acp/src/wire.ts
similarity index 100%
rename from plugins/provider-acp/src/wire.ts
rename to packages/provider-bridge-acp/src/wire.ts
diff --git a/packages/provider-bridge-acp/tsconfig.json b/packages/provider-bridge-acp/tsconfig.json
new file mode 100644
index 0000000000..945db56508
--- /dev/null
+++ b/packages/provider-bridge-acp/tsconfig.json
@@ -0,0 +1,11 @@
+{
+  "extends": [
+    "@bb/tsconfig/base.json",
+    "@bb/tsconfig/typecheck-overrides.json"
+  ],
+  "compilerOptions": {
+    "rootDir": ".",
+    "types": ["node"]
+  },
+  "include": ["src"]
+}
diff --git a/packages/provider-bridge-acp/vitest.config.ts b/packages/provider-bridge-acp/vitest.config.ts
new file mode 100644
index 0000000000..eae740f21e
--- /dev/null
+++ b/packages/provider-bridge-acp/vitest.config.ts
@@ -0,0 +1,10 @@
+import { defineWorkspaceTestConfig } from "../../vitest.shared.js";
+
+export default defineWorkspaceTestConfig({
+  test: {
+    silent: "passed-only",
+    name: "@bb/provider-bridge-acp",
+    include: ["src/**/*.test.ts"],
+    exclude: ["dist/**", "node_modules/**"],
+  },
+});
diff --git a/packages/provider-bridge-protocol/src/testing/parity.ts b/packages/provider-bridge-protocol/src/testing/parity.ts
index 643677b3ae..254edd2b42 100644
--- a/packages/provider-bridge-protocol/src/testing/parity.ts
+++ b/packages/provider-bridge-protocol/src/testing/parity.ts
@@ -75,7 +75,7 @@ export const FIRST_PARTY_BRIDGE_MODULES: Readonly<
     pluginId: "provider-claude-code",
   },
   acp: {
-    modulePath: "plugins/provider-acp/src/bridge/bridge.ts",
+    modulePath: "plugins/provider-acp/src/host.ts",
     pluginId: "provider-acp",
   },
   pi: {
diff --git a/packages/scripts/test/provider-literal-ratchet.test.mjs b/packages/scripts/test/provider-literal-ratchet.test.mjs
index 5efa908523..19a174c876 100644
--- a/packages/scripts/test/provider-literal-ratchet.test.mjs
+++ b/packages/scripts/test/provider-literal-ratchet.test.mjs
@@ -93,6 +93,19 @@ describe("scanTree (pure)", () => {
     expect(scanTree(dir).total).toBe(0);
   });
 
+  // The published ACP bridge kit is a provider implementation that lives
+  // under packages/ so the plugin SDK can re-export it; it gets the same
+  // carve-out a provider plugin does. Its neighbours do not.
+  it("excludes the published provider bridge kit but not its neighbours", () => {
+    write(
+      "packages/provider-bridge-acp/src/dialect.ts",
+      'const dialects = { "cursor-agent": "cursor" };\n',
+    );
+    expect(scanTree(dir).total).toBe(0);
+    write("packages/provider-bridge-protocol/src/a.ts", 'const id = "cursor";\n');
+    expect(scanTree(dir).total).toBe(1);
+  });
+
   it('providerLiteralRegex does not double-count `providerId === "codex"`', () => {
     const line = 'if (providerId === "codex") {}';
     expect(line.match(providerLiteralRegex())).toHaveLength(1);
diff --git a/plugins/provider-acp/README.md b/plugins/provider-acp/README.md
index ae1f58c7cf..e7e5d997b0 100644
--- a/plugins/provider-acp/README.md
+++ b/plugins/provider-acp/README.md
@@ -1,12 +1,26 @@
 # ACP providers
 
-First-party plugin for ACP (Agent Client Protocol) agent providers.
-
-Today this plugin registers only the `acp-cursor` (Cursor) provider
-declaration. The rest of BB's ACP surface — the known-agents list (opencode,
-Grok, Hermes Agent, OMP, ...) and the `customAcpAgents` server config — stays
-composed server-side transitionally. This plugin is destined to own the
-Cursor profile, the known-agents list, and the `customAcpAgents` config
-(which then finally gets a settings UI); until that migration lands, only the
-Cursor declaration lives here and the server keeps composing the other ACP
-providers into listings itself.
+First-party plugin for ACP (Agent Client Protocol) agent providers: Cursor,
+opencode, omp, Grok Build and Hermes Agent.
+
+The plugin has no bridge of its own. Every agent it registers runs on the
+published ACP kit, `@get-bb/plugin-sdk/provider-bridge/acp`, which its
+`bb.host` entry re-exports in one line (`src/host.ts`). That is the whole
+point of the kit: a third-party plugin adds an ACP agent exactly the way this
+one does, with no bb-side code, and `public-sdk-only.test.ts` proves this
+plugin takes no shortcut — no file here may import a private `@bb/*` package.
+
+What lives here:
+
+- `server.ts` — the provider registrations: ids, display names, icons,
+  capabilities, and the bridge options each agent launches with
+  (`acpLaunchSpec`, and `acpDialect` for the agents whose vendor side
+  channels the kit reads).
+- `src/host.ts` — the `bb.host` artifact: one re-export of the kit's bridge.
+- `icons/` — the provider logos.
+
+The kit itself, including the ACP wire schema, the delta translation, the
+per-agent dialects and the bridge process, is `packages/provider-bridge-acp`.
+
+Still composed server-side, transitionally: the `customAcpAgents` server
+config for user-configured agents.
diff --git a/plugins/provider-acp/package.json b/plugins/provider-acp/package.json
index 2966376bf2..e265436a9d 100644
--- a/plugins/provider-acp/package.json
+++ b/plugins/provider-acp/package.json
@@ -14,7 +14,7 @@
       "icon": "./icons/acp.svg"
     },
     "server": "./server.ts",
-    "host": "./src/bridge/bridge.ts"
+    "host": "./src/host.ts"
   },
   "keywords": [
     "bb-plugin"
@@ -24,10 +24,6 @@
     "typecheck": "tsc --noEmit"
   },
   "devDependencies": {
-    "@bb/agent-runtime": "workspace:*",
-    "@bb/domain": "workspace:*",
-    "@bb/host-daemon-contract": "workspace:*",
-    "@bb/provider-bridge-protocol": "workspace:*",
     "@modelcontextprotocol/sdk": "^1.29.0",
     "@types/node": "^22.0.0",
     "typescript": "npm:@typescript/typescript6@^6.0.2",
diff --git a/plugins/provider-acp/public-sdk-only.test.ts b/plugins/provider-acp/public-sdk-only.test.ts
new file mode 100644
index 0000000000..7e54b6299c
--- /dev/null
+++ b/plugins/provider-acp/public-sdk-only.test.ts
@@ -0,0 +1,111 @@
+/**
+ * The first-party ACP plugin has no privilege: it reaches every capability
+ * through the public SDK alone, exactly as a third-party ACP plugin (Amp)
+ * would. No file in this package may import a private `@bb/*` workspace
+ * package — not the plugin code, not the tests. Plugin code may import only
+ * `@get-bb/plugin-sdk` (and its published subpaths), `zod`, node built-ins,
+ * and its own files; tests may add the published testing kit and the test
+ * runner.
+ *
+ * A `@bb/*` import would still typecheck and run inside this monorepo, which
+ * is exactly why it needs a test: the workspace hides the privilege. This is
+ * the same guard the echo-provider canary carries (#2189).
+ */
+import { readdirSync, readFileSync } from "node:fs";
+import { dirname, join, relative } from "node:path";
+import { fileURLToPath } from "node:url";
+import { describe, expect, it } from "vitest";
+
+const packageRoot = dirname(fileURLToPath(import.meta.url));
+
+const SKIPPED_DIRECTORIES = new Set(["node_modules", "dist"]);
+const SOURCE_EXTENSIONS = /\.(?:[cm]?[jt]s|tsx)$/u;
+
+/** Specifiers plugin code (server, host) may import. */
+const PLUGIN_IMPORT_ALLOWLIST = [
+  /^@get-bb\/plugin-sdk$/u,
+  /^@get-bb\/plugin-sdk\/(?:provider-bridge|host|app)$/u,
+  /^@get-bb\/plugin-sdk\/provider-bridge\/acp$/u,
+  /^zod$/u,
+  /^node:/u,
+  /^\.\.?\//u,
+];
+
+/** What a test file may import beyond the plugin allowlist. */
+const TEST_IMPORT_ALLOWLIST = [
+  /^@get-bb\/plugin-sdk\/provider-bridge\/testing$/u,
+  /^vitest$/u,
+];
+
+const IMPORT_SPECIFIER_PATTERN =
+  /(?:\bfrom\s*|\bimport\s*\(?\s*|\brequire\s*\(\s*)["']([^"']+)["']/gu;
+
+function listSourceFiles(directory: string): string[] {
+  const files: string[] = [];
+  for (const entry of readdirSync(directory, { withFileTypes: true })) {
+    if (entry.isDirectory()) {
+      if (!SKIPPED_DIRECTORIES.has(entry.name)) {
+        files.push(...listSourceFiles(join(directory, entry.name)));
+      }
+      continue;
+    }
+    if (SOURCE_EXTENSIONS.test(entry.name)) {
+      files.push(join(directory, entry.name));
+    }
+  }
+  return files;
+}
+
+function importSpecifiers(source: string): string[] {
+  return [...source.matchAll(IMPORT_SPECIFIER_PATTERN)].map(
+    (match) => match[1] ?? "",
+  );
+}
+
+function isTestFile(path: string): boolean {
+  return /\.test\.[cm]?[jt]sx?$/u.test(path);
+}
+
+describe("provider-acp imports only the public SDK", () => {
+  const files = listSourceFiles(packageRoot);
+
+  it("scans the plugin's source files", () => {
+    const names = files.map((file) => relative(packageRoot, file));
+    expect(names).toContain("server.ts");
+    expect(names).toContain(join("src", "host.ts"));
+  });
+
+  for (const file of files) {
+    const name = relative(packageRoot, file);
+    it(`${name} has no @bb/* import and stays inside the allowlist`, () => {
+      const source = readFileSync(file, "utf8");
+      const specifiers = importSpecifiers(source);
+      const privateImports = specifiers.filter((specifier) =>
+        specifier.startsWith("@bb/"),
+      );
+      expect(privateImports, `${name} imports private packages`).toEqual([]);
+
+      const allowlist = isTestFile(file)
+        ? [...PLUGIN_IMPORT_ALLOWLIST, ...TEST_IMPORT_ALLOWLIST]
+        : PLUGIN_IMPORT_ALLOWLIST;
+      const disallowed = specifiers.filter(
+        (specifier) => !allowlist.some((pattern) => pattern.test(specifier)),
+      );
+      expect(disallowed, `${name} imports outside the allowlist`).toEqual([]);
+    });
+  }
+
+  it("declares no @bb/* dependency in package.json", () => {
+    const manifest = JSON.parse(
+      readFileSync(join(packageRoot, "package.json"), "utf8"),
+    ) as {
+      dependencies?: Record<string, string>;
+      devDependencies?: Record<string, string>;
+    };
+    const declared = [
+      ...Object.keys(manifest.dependencies ?? {}),
+      ...Object.keys(manifest.devDependencies ?? {}),
+    ];
+    expect(declared.filter((name) => name.startsWith("@bb/"))).toEqual([]);
+  });
+});
diff --git a/plugins/provider-acp/server.ts b/plugins/provider-acp/server.ts
index 4eebbc5f50..35c535d862 100644
--- a/plugins/provider-acp/server.ts
+++ b/plugins/provider-acp/server.ts
@@ -69,7 +69,7 @@ const ACP_PROVIDERS: readonly PluginProviderDeclaration[] = [
     experimental_serviceTiers: [...ACP_SERVICE_TIERS],
     experimental_bridgeOptions: {
       // Which vendor side channels the bridge reads for this agent
-      // (plugins/provider-acp/src/dialect.ts). Declared per registration so
+      // (packages/provider-bridge-acp/src/dialect.ts). Declared per registration so
       // a third-party plugin that registers a known agent gets the same
       // reporting fidelity a first-party registration does.
       acpDialect: "cursor",
diff --git a/plugins/provider-acp/src/host.ts b/plugins/provider-acp/src/host.ts
new file mode 100644
index 0000000000..5b9573cc38
--- /dev/null
+++ b/plugins/provider-acp/src/host.ts
@@ -0,0 +1,9 @@
+/**
+ * The plugin's `bb.host` artifact.
+ *
+ * Every ACP agent bb ships runs on the published ACP kit — the same module a
+ * third-party plugin uses — so this plugin's host side is one re-export. The
+ * daemon's bridge bootstrap imports the artifact and looks for the named
+ * `experimental_providerBridge` export.
+ */
+export { experimental_acpProviderBridge as experimental_providerBridge } from "@get-bb/plugin-sdk/provider-bridge/acp";
diff --git a/plugins/provider-acp/src/bridge/issue-1688-cursor-list-models.txt b/plugins/provider-acp/src/issue-1688-cursor-list-models.txt
similarity index 100%
rename from plugins/provider-acp/src/bridge/issue-1688-cursor-list-models.txt
rename to plugins/provider-acp/src/issue-1688-cursor-list-models.txt
diff --git a/plugins/provider-acp/src/bridge/issue-1688-grok-4.6-primary.test.ts b/plugins/provider-acp/src/issue-1688-grok-4.6-primary.test.ts
similarity index 86%
rename from plugins/provider-acp/src/bridge/issue-1688-grok-4.6-primary.test.ts
rename to plugins/provider-acp/src/issue-1688-grok-4.6-primary.test.ts
index a945e248b6..0bff528605 100644
--- a/plugins/provider-acp/src/bridge/issue-1688-grok-4.6-primary.test.ts
+++ b/plugins/provider-acp/src/issue-1688-grok-4.6-primary.test.ts
@@ -11,12 +11,12 @@
  */
 import { readFileSync } from "node:fs";
 import { describe, expect, it } from "vitest";
-import { CURSOR_PRIMARY_MODELS } from "../../server.js";
 import {
-  buildAgentModelCatalog,
-  parseAgentModelLines,
-  splitPrimaryModels,
-} from "./model-catalog.js";
+  experimental_buildAcpAgentModelCatalog as buildAgentModelCatalog,
+  experimental_parseAcpAgentModelLines as parseAgentModelLines,
+  experimental_splitAcpPrimaryModels as splitPrimaryModels,
+} from "@get-bb/plugin-sdk/provider-bridge/acp";
+import { CURSOR_PRIMARY_MODELS } from "../server.js";
 
 // Captured with `cursor-agent --list-models` (2026.08.11-e8db854).
 const CURSOR_LIST_MODELS = readFileSync(
diff --git a/plugins/provider-acp/tsconfig.json b/plugins/provider-acp/tsconfig.json
index 6acac8aade..e76b240e49 100644
--- a/plugins/provider-acp/tsconfig.json
+++ b/plugins/provider-acp/tsconfig.json
@@ -4,7 +4,10 @@
     "target": "ES2022",
     "module": "ESNext",
     "moduleResolution": "bundler",
-    "lib": ["ES2022", "DOM"],
+    "lib": [
+      "ES2022",
+      "DOM"
+    ],
     "noEmit": true,
     "skipLibCheck": true,
     "paths": {
@@ -13,9 +16,19 @@
       ],
       "@get-bb/plugin-sdk/app": [
         "../../packages/plugin-sdk/bundled-types/bb-plugin-sdk-app.d.ts"
+      ],
+      "@get-bb/plugin-sdk/provider-bridge/acp": [
+        "../../packages/plugin-sdk/bundled-types/bb-plugin-sdk-provider-bridge-acp.d.ts"
       ]
     },
-    "types": ["node"]
+    "types": [
+      "node"
+    ]
   },
-  "include": ["server.ts", "src", "vitest.config.ts"]
+  "include": [
+    "server.ts",
+    "src",
+    "public-sdk-only.test.ts",
+    "vitest.config.ts"
+  ]
 }
diff --git a/plugins/provider-acp/vitest.config.ts b/plugins/provider-acp/vitest.config.ts
index 59659ca205..142f591353 100644
--- a/plugins/provider-acp/vitest.config.ts
+++ b/plugins/provider-acp/vitest.config.ts
@@ -4,7 +4,7 @@ export default defineWorkspaceTestConfig({
   test: {
     silent: "passed-only",
     name: "bb-plugin-provider-acp",
-    include: ["src/**/*.test.ts"],
+    include: ["*.test.ts", "src/**/*.test.ts"],
     exclude: ["node_modules/**", "dist/**"],
   },
 });
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 01ce3f67e0..6adf7f9aee 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2179,6 +2179,9 @@ importers:
       '@bb/process-utils':
         specifier: workspace:*
         version: link:../process-utils
+      '@bb/provider-bridge-acp':
+        specifier: workspace:*
+        version: link:../provider-bridge-acp
       '@bb/provider-bridge-protocol':
         specifier: workspace:*
         version: link:../provider-bridge-protocol
@@ -2268,6 +2271,43 @@ importers:
         specifier: ^4.1.1
         version: 4.1.1(@opentelemetry/api@1.9.1)(@types/node@22.19.10)(jsdom@29.0.1(@noble/hashes@2.0.1))(msw@2.12.14(@types/node@22.19.10)(@typescript/typescript6@6.0.2))(vite@8.0.12(@types/node@22.19.10)(esbuild@0.28.1)(jiti@2.7.0)(terser@5.50.0)(tsx@4.23.1)(yaml@2.9.0))
 
+  packages/provider-bridge-acp:
+    dependencies:
+      '@bb/domain':
+        specifier: workspace:*
+        version: link:../domain
+      '@bb/host-daemon-contract':
+        specifier: workspace:*
+        version: link:../host-daemon-contract
+      '@bb/process-utils':
+        specifier: workspace:*
+        version: link:../process-utils
+      '@bb/provider-bridge-protocol':
+        specifier: workspace:*
+        version: link:../provider-bridge-protocol
+      zod:
+        specifier: 4.3.6
+        version: 4.3.6
+    devDependencies:
+      '@bb/tsconfig':
+        specifier: workspace:*
+        version: link:../tsconfig
+      '@modelcontextprotocol/sdk':
+        specifier: ^1.29.0
+        version: 1.29.0(zod@4.3.6)
+      '@types/node':
+        specifier: ^22.0.0
+        version: 22.19.10
+      typescript:
+        specifier: npm:@typescript/typescript6@^6.0.2
+        version: '@typescript/typescript6@6.0.2'
+      typescript-7:
+        specifier: npm:typescript@^7.0.2
+        version: typescript@7.0.2
+      vitest:
+        specifier: ^4.1.1
+        version: 4.1.1(@opentelemetry/api@1.9.1)(@types/node@22.19.10)(jsdom@29.0.1(@noble/hashes@2.0.1))(msw@2.12.14(@types/node@22.19.10)(@typescript/typescript6@6.0.2))(vite@8.0.12(@types/node@22.19.10)(esbuild@0.28.1)(jiti@2.7.0)(terser@5.50.0)(tsx@4.23.1)(yaml@2.9.0))
+
   packages/provider-bridge-protocol:
     dependencies:
       '@bb/domain':
@@ -3292,18 +3332,6 @@ importers:
         specifier: 4.3.6
         version: 4.3.6
     devDependencies:
-      '@bb/agent-runtime':
-        specifier: workspace:*
-        version: link:../../packages/agent-runtime
-      '@bb/domain':
-        specifier: workspace:*
-        version: link:../../packages/domain
-      '@bb/host-daemon-contract':
-        specifier: workspace:*
-        version: link:../../packages/host-daemon-contract
-      '@bb/provider-bridge-protocol':
-        specifier: workspace:*
-        version: link:../../packages/provider-bridge-protocol
       '@modelcontextprotocol/sdk':
         specifier: ^1.29.0
         version: 1.29.0(zod@4.3.6)
@@ -19273,9 +19301,7 @@ snapshots:
       metro-runtime: 0.84.5
     transitivePeerDependencies:
       - '@babel/core'
-      - bufferutil
       - supports-color
-      - utf-8-validate
 
   '@react-native/normalize-colors@0.79.6': {}
 
diff --git a/scripts/check-provider-literal-ratchet.mjs b/scripts/check-provider-literal-ratchet.mjs
index a8bf45f207..ce1318ef88 100755
--- a/scripts/check-provider-literal-ratchet.mjs
+++ b/scripts/check-provider-literal-ratchet.mjs
@@ -54,7 +54,19 @@ const EXCLUDED_SEGMENTS = new Set([
   "stories",
   "dev", // dev-only fixture screens (apps/mobile/src/screens/dev)
 ]);
-const EXCLUDED_PREFIXES = [join("plugins", "provider-"), join("examples", "")];
+/**
+ * Provider implementations are allowed to name their own provider; the
+ * ratchet exists to keep provider ids out of CORE. `plugins/provider-*` is
+ * one such implementation, and so is the published ACP bridge kit — the same
+ * code, moved into `packages/` so the plugin SDK can re-export it
+ * (`@get-bb/plugin-sdk/provider-bridge/acp`). It carries no bb provider id
+ * today: it selects behavior by the agent's dialect, never by a provider id.
+ */
+const EXCLUDED_PREFIXES = [
+  join("plugins", "provider-"),
+  join("packages", "provider-bridge-acp"),
+  join("examples", ""),
+];
 const EXCLUDED_FILE_RE =
   /\.(test|spec|stories)\.[cm]?[jt]sx?$|\.snap$|\.d\.ts$/;
 const INCLUDED_FILE_RE = /\.[cm]?[jt]sx?$/; // ts tsx js jsx mjs cjs mts cts