feat: custom answers

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.0.4]
+
+### Added
+
+- `CustomAnswersStrategy`: new strategy that returns preconfigured answers for exact-match questions.
+
 ## [0.0.3]
 
 ### Added

README.md

@@ -13,6 +13,7 @@ OpenAI-compatible mock server for testing LLM integrations.
 - Default mirror strategy (echoes input as output)
 - **Tool calling support** — trigger phrase–driven tool call responses when `tools` are present in the request using `call tool '<name>' with '<json>'`
 - **Error simulation** — trigger phrase–driven error responses using `raise error <json>` in the last user message
+- **Custom answers** — return preconfigured answers for exact-match questions via `customReplies` in `config.yaml`
 - Streaming support for both Chat Completions and Responses APIs (including `stream_options.include_usage`)
 
 ## Quick Start
@@ -99,12 +100,20 @@ cors:
     - "http://localhost:8000"
 
 # Ordered list of strategies to try (first non-empty result wins)
-# Available: ErrorStrategy, ToolCallStrategy, MirrorStrategy
+# Available: ErrorStrategy, CustomAnswersStrategy, ToolCallStrategy, MirrorStrategy
 strategies:
   - ErrorStrategy
+  - CustomAnswersStrategy
   - ToolCallStrategy
   - MirrorStrategy
 
+# Inline question→answer pairs for CustomAnswersStrategy (exact-match, case-sensitive)
+customReplies:
+  - question: How are you today?
+    answer: I'm fine. how are you?
+  - question: What is 1+1?
+    answer: 2
+
 models:
   - id: "gpt-4o"
     created: 1715367049
@@ -218,6 +227,28 @@ client.chat.completions.create(
 Only the last user message is checked. System/assistant/tool messages are ignored.
 Works on both `/chat/completions` and `/responses` endpoints.
 
+### Custom Answers
+
+When `CustomAnswersStrategy` is included in the `strategies` list, llmock checks the last user message against a list of preconfigured question/answer pairs (exact match, case-sensitive, whitespace trimmed). Configure the pairs inline in `config.yaml`:
+
+```yaml
+strategies:
+  - ErrorStrategy
+  - CustomAnswersStrategy
+  - ToolCallStrategy
+  - MirrorStrategy
+
+customReplies:
+  - question: How are you today?
+    answer: I'm fine. how are you?
+  - question: What is 1+1?
+    answer: 2
+```
+
+If the message matches a `question`, the corresponding `answer` is returned. If no match is found, the strategy falls through to the next one (e.g. `MirrorStrategy`).
+
+Works on both `/chat/completions` and `/responses` endpoints.
+
 ## Development
 
 ### Run Tests

config.yaml

@@ -30,5 +30,13 @@ models:
 # Ordered list of strategies (first non-empty result wins)
 strategies:
   - ErrorStrategy
+  - CustomAnswersStrategy
   - ToolCallStrategy
   - MirrorStrategy
+
+# Inline question→answer pairs for CustomAnswersStrategy (exact-match, case-sensitive)
+# customReplies:
+#   - question: How are you today?
+#     answer: I'm fine. how are you?
+#   - question: What is 1+1?
+#     answer: 2

docs/llmock-skill/references/config.yaml

@@ -30,5 +30,13 @@ models:
 # Ordered list of strategies (first non-empty result wins)
 strategies:
   - ErrorStrategy
+  - CustomAnswersStrategy
   - ToolCallStrategy
   - MirrorStrategy
+
+# Inline question→answer pairs for CustomAnswersStrategy (exact-match, case-sensitive)
+# customReplies:
+#   - question: How are you today?
+#     answer: I'm fine. how are you?
+#   - question: What is 1+1?
+#     answer: 2

src/llmock/strategies/factory.py

@@ -16,13 +16,21 @@
     ChatErrorStrategy,
     ResponseErrorStrategy,
 )
+from llmock.strategies.strategy_custom_answers import (
+    ChatCustomAnswersStrategy,
+    ResponseCustomAnswersStrategy,
+)
 from llmock.strategies.strategy_tool_call import (
     ChatToolCallStrategy,
     ResponseToolCallStrategy,
 )
 
 # Short strategy names used in config → (ChatClass, ResponseClass)
 _STRATEGIES: dict[str, tuple[type, type]] = {
+    "CustomAnswersStrategy": (
+        ChatCustomAnswersStrategy,
+        ResponseCustomAnswersStrategy,
+    ),
     "ErrorStrategy": (ChatErrorStrategy, ResponseErrorStrategy),
     "MirrorStrategy": (ChatMirrorStrategy, ResponseMirrorStrategy),
     "ToolCallStrategy": (ChatToolCallStrategy, ResponseToolCallStrategy),

src/llmock/strategies/strategy_composition.py

@@ -22,7 +22,12 @@
 
 logger = logging.getLogger(__name__)
 
-_DEFAULT_STRATEGIES = ["ErrorStrategy", "ToolCallStrategy", "MirrorStrategy"]
+_DEFAULT_STRATEGIES = [
+    "ErrorStrategy",
+    "CustomAnswersStrategy",
+    "ToolCallStrategy",
+    "MirrorStrategy",
+]
 
 
 class ChatCompositionStrategy:

src/llmock/strategies/strategy_custom_answers.py

@@ -0,0 +1,81 @@
+"""Custom answers strategy - return preconfigured answers for exact-match questions.
+
+Reads the ``customReplies`` list directly from config.  The list must have
+the following structure in ``config.yaml``::
+
+    customReplies:
+      - question: How are you today?
+        answer: I'm fine. how are you?
+      - question: What is 1+1?
+        answer: 2
+
+When the last user message exactly matches a ``question`` (case-sensitive,
+stripped of leading/trailing whitespace), the corresponding ``answer`` is
+returned as a text response.  If no match is found, an empty list is
+returned so the next strategy in the composition chain runs.
+
+If ``customReplies`` is not present in config the strategy passes through
+silently (empty list).
+"""
+
+import logging
+from typing import Any
+
+from llmock.schemas.chat import ChatCompletionRequest
+from llmock.schemas.responses import ResponseCreateRequest
+from llmock.strategies.base import StrategyResponse, text_response
+from llmock.utils.chat import (
+    extract_last_user_text_chat,
+    extract_last_user_text_response,
+)
+
+logger = logging.getLogger(__name__)
+
+CONFIG_KEY = "customReplies"
+
+
+def _build_replies(entries: list[Any]) -> dict[str, str]:
+    """Build a question→answer mapping from a list of config entries."""
+    return {
+        str(entry["question"]).strip(): str(entry["answer"])
+        for entry in entries
+        if isinstance(entry, dict) and "question" in entry and "answer" in entry
+    }
+
+
+def _match(content: str | None, replies: dict[str, str]) -> list[StrategyResponse]:
+    """Return a response if *content* exactly matches a question, else []."""
+    if content is None:
+        return []
+    answer = replies.get(content.strip())
+    if answer is None:
+        return []
+    return [text_response(answer)]
+
+
+class ChatCustomAnswersStrategy:
+    """Exact-match custom answers strategy for the Chat Completions API."""
+
+    def __init__(self, config: dict[str, Any]) -> None:
+        entries = config.get(CONFIG_KEY, [])
+        self._replies: dict[str, str] = _build_replies(entries)
+
+    def generate_response(
+        self, request: ChatCompletionRequest
+    ) -> list[StrategyResponse]:
+        content = extract_last_user_text_chat(request)
+        return _match(content, self._replies)
+
+
+class ResponseCustomAnswersStrategy:
+    """Exact-match custom answers strategy for the Responses API."""
+
+    def __init__(self, config: dict[str, Any]) -> None:
+        entries = config.get(CONFIG_KEY, [])
+        self._replies: dict[str, str] = _build_replies(entries)
+
+    def generate_response(
+        self, request: ResponseCreateRequest
+    ) -> list[StrategyResponse]:
+        content = extract_last_user_text_response(request)
+        return _match(content, self._replies)