Mockd

Mockd is an open source, Apache 2.0 multi-protocol API mocking server. It is built for mocking HTTP, GraphQL, gRPC, WebSocket, MQTT, SSE, and SOAP APIs, with a focus on recording real traffic, matching requests, and returning dynamic responses.

The product describes itself as a high-performance mock server and highlights a local-first design that runs on the user’s machine and works offline. Its feature set includes record and replay through a MITM proxy, smart request matching with 15+ criteria such as path patterns, headers, JSONPath, regex, and mTLS identity, and dynamic responses using 35 built-in faker types, template variables, JSONPath extraction, UUIDs, timestamps, and sequences. Mockd also includes in-memory CRUD simulation, multi-protocol state sharing, mock verification, and 10 built-in chaos profiles for resilience testing.

Mockd exposes a CLI, an admin API, and an MCP server. The site shows a terminal workflow with commands such as mockd start and mockd add, and says the MCP server includes 18 MCP tools, a zero-setup auto-start daemon, pre-built agent configuration templates, and publication on the MCP Registry. It also names Cursor, Windsurf, and Claude Code as supported AI tools for the MCP server. The interface and examples are presented around HTTP/REST, GraphQL, gRPC, WebSocket, and MQTT, while the feature list also includes SSE and SOAP.

Pricing and licensing are presented as open source, with “Start Free” and “Contact Enterprise Sales” calls to action. The page also describes free observability features, including Prometheus metrics, OpenTelemetry tracing, Loki log aggregation, audit logging, rate limiting simulation, and Grafana dashboards. Performance claims shown on the page include 50K+ HTTP requests per second and 50K+ MQTT messages per second.