aimock Documentation
Complete mock infrastructure for AI application testing. One package, zero dependencies.
Quick Start
Mock LLM APIs
import { LLMock } from "@copilotkit/aimock";
const mock = new LLMock();
await mock.start();
mock.onMessage("hello", { content: "Hi there!" });Mock your entire stack
{
"llm": { "fixtures": "./fixtures/llm" },
"mcp": { "tools": [{ "name": "search", "result": "3 results" }] },
"a2a": { "agents": [{ "name": "planner" }] },
"vector": { "collections": [{ "name": "docs", "dimension": 1536 }] }
}What's New
Script source citations on OpenAI, Claude and Gemini replies, and generated images on the Responses API and Gemini, in each provider's own format
Docs →Send provider events or JSON exactly as written, for fields aimock does not model yet, with timing, chaos and disconnects still applied
Docs →Every LLM provider stops sending and journals the request when the client hangs up, and non-streaming replies on every provider can opt in to realistic timing
Docs →Gemini and Anthropic model lists, token counts, and opt-in provider-native 401s, so you can test model pickers and bad-key handling
Docs →Opt-in faults that real models produce: invalid tool JSON, unknown tools, schema violations, length stops, refusals, and empty replies
Docs →Record a live MCP server once, replay it offline, script tool answers per scenario, and see which fakes each test used
Docs →
Opt-in namespaced functions and custom tool calls, plus commentary /
final_answer message phases (new in 1.46.0)
Files, Batches, Fine-tuning jobs, and Vector Stores with deterministic search
Docs →The Suite
| Mock | What it does | Docs |
|---|---|---|
| LLM Providers | OpenAI, Claude, Gemini, Gemini Interactions, Bedrock, Azure, Vertex AI, Ollama, Cohere, OpenRouter | Docs → |
| Multimedia | Image generation, TTS, transcription, video | Docs → |
| MCP Protocol | Tools, resources, prompts, session management | Docs → |
| A2A Protocol | Agent cards, message routing, SSE streaming | Docs → |
| AG-UI Protocol | Event streams for CopilotKit frontends | Docs → |
| Vector DBs | Pinecone, Qdrant, ChromaDB | Docs → |
| Files | Upload, list, retrieve, download and delete, byte-exact | Docs → |
| Services | Search, rerank, moderation | Docs → |