Mock LLM provider for customer services scenarios. Always helpful, never useful.

Testing utilities for llmist - mock LLM responses and test agents

A configurable mock LLM API server for testing and development

A standalone mock LLM server for deterministic testing: OpenAI, Anthropic, and Responses API formats

Simple OpenAI compatible Mock API server. Useful for deterministic testing of AI applications.

Mock LLM inference service for Matrix Chat development and testing

**Note:** More details on user side API can be found in [Jest documentation](https://jestjs.io/docs/mock-function-api).

Mock infrastructure for AI application testing — LLM APIs, image generation, image editing, text-to-speech, transcription, audio translation, audio generation, video generation, embeddings, MCP tools, A2A agents, AG-UI event streams, vector databases, sea

Seamless REST/GraphQL API mocking library for browser and Node.js.

Testing utilities for OrkaJS agents — mock LLM, AgentTestBed, Vitest matchers

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Easy and powerful mocking of AWS SDK v3 Clients

Scripted mock LLM provider for deterministic testing and demos in the emerge harness.

Mock a canvas in your jest tests.

Axios adapter that allows to easily mock requests

Type safe mocking extensions for jest

fetch mock for jest

A Mock API for AWS Kinesis

Type safe mocking extensions for vitest, forked from jest-mock-extended

fetch mock for vitest