AIMock: One Mock Server For Your Entire AI Stack

TL;DR Our CI was flaky, our tests hit live APIs, and every run burned tokens unnecessarily. So the CopilotKit team built AIMock - a mock server that covers your entire agentic stack so your tests are fast, free, and actually reliable. Let's dive in! Why we built AIMock It started with LLM mocking. We built LLMock, open-sourced it, and thought we were done. But a single agent request in 2026 can touch six or seven services before it returns a response: the LLM, an MCP tool server, a vector database, a reranker, a web search API, a moderation layer, and a sub-agent over A2A. Most teams mock one of them. The other six are live, non-deterministic, and quietly making your test suite a lie. That is why LLMock became AIMock . npm install @copilotkit/aimock Table of Contents AI apps in 2026 call a lot more than just an LLM Introducing AIMock: mock your entire agentic stack LLMock: full streaming, tool calls, reasoning across every major provider MCPMock: a mock MCP server for testing tool inte