mockd
One binary. Seven protocols. Zero dependencies.
Mock HTTP, gRPC, GraphQL, WebSocket, MQTT, SSE, and SOAP APIs from a single CLI tool. Import from OpenAPI, Postman, WireMock, HAR, or cURL. Share mocks instantly via built-in cloud tunneling.
Why mockd?
| mockd | WireMock | Mockoon | json-server | Prism | MockServer | |
|---|---|---|---|---|---|---|
| Single binary, no runtime | :white_check_mark: | :x: JVM | :x: Node | :x: Node | :x: Node | :x: JVM |
| HTTP mocking | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
| gRPC mocking | :white_check_mark: | 🔌 Ext | :x: | :x: | :x: | :white_check_mark: |
| GraphQL mocking | :white_check_mark: | 🔌 Ext | :x: | :x: | :x: | :x: |
| WebSocket mocking | :white_check_mark: | 🔌 Ext | :x: | :x: | :x: | :x: |
| MQTT broker | :white_check_mark: | :x: | :x: | :x: | :x: | :x: |
| SOAP mocking | :white_check_mark: | :x: | :x: | :x: | :x: | :white_check_mark: |
| SSE streaming | :white_check_mark: | :x: | :x: | :x: | :x: | :x: |
| OAuth/OIDC provider | :white_check_mark: | :x: | :x: | :x: | :x: | :x: |
| Chaos engineering | :white_check_mark: | :white_check_mark: | :x: | :x: | :x: | :x: |
| Stateful CRUD | :white_check_mark: | :x: | :white_check_mark: | :white_check_mark: | :x: | :x: |
| Cloud tunnel sharing | :white_check_mark: | :x: | :white_check_mark: | :x: | :x: | :x: |
| Proxy recording & replay | :white_check_mark: | :white_check_mark: | :white_check_mark: | :x: | :x: | :white_check_mark: |
| Import OpenAPI/Postman/HAR | :white_check_mark: | :white_check_mark: | :white_check_mark: | :x: | :white_check_mark: | :white_check_mark: |
| Built-in web dashboard | :white_check_mark: | :x: | :white_check_mark: | :x: | :x: | :x: |
| MCP server (AI-native) | :white_check_mark: | :x: | :x: | :x: | :x: | :x: |
🔌 Ext = available via separate extension JAR, not bundled with WireMock core. mockd includes all protocols natively in a single binary.
Install
# Quick install
curl -sSL https://get.mockd.io | sh
# Homebrew
brew install getmockd/tap/mockd
# Docker
docker run -p 4280:4280 -p 4290:4290 ghcr.io/getmockd/mockd:latest
# Go
go install github.com/getmockd/mockd/cmd/mockd@latest
Pre-built binaries for Linux, macOS, and Windows are available on the Releases page.
Quick Start
# Start the mock server
mockd start
# Mock an HTTP endpoint
mockd add http --path /api/users --body '[{"id": 1, "name": "Alice"}]'
# Test it
curl http://localhost:4280/api/users
# → [{"id": 1, "name": "Alice"}]
# Mock a GraphQL API
mockd add graphql --path /graphql --operation users \
--response '[{"id": 1, "name": "Alice"}]'
# Mock a gRPC service
mockd add grpc --proto ./service.proto \
--service myapp.UserService --rpc-method GetUser \
--response '{"id": 1, "name": "Alice"}'
# Mock a WebSocket endpoint
mockd add websocket --path /ws/chat --echo
# Import from OpenAPI, Postman, or cURL
mockd import openapi.yaml
mockd import collection.json
mockd import "curl -X GET https://api.example.com/users"
Features
Multi-Protocol Mocking
Mock seven protocols from a single tool with a unified CLI and Admin API:
| Protocol | Port | Example |
|---|---|---|
| HTTP/HTTPS | 4280 | mockd add http --path /api/hello --body '{"msg":"hi"}' |
| gRPC | 50051 | mockd add grpc --proto svc.proto --service Greeter --rpc-method Greet |
| GraphQL | 4280 | mockd add graphql --path /graphql --operation hello |
| WebSocket | 4280 | mockd add websocket --path /ws --echo |
| MQTT | 1883 | mockd add mqtt --topic sensors/temp --payload '{"temp":72}' |
| SSE | 4280 | mockd add http --path /events --sse --sse-event 'data: hello' |
| SOAP | 4280 | mockd add soap --path /soap --operation GetWeather --response '<OK/>' |
Import & Export
Bring your existing API definitions — no rewriting needed:
mockd import openapi.yaml # OpenAPI 3.x / Swagger 2.0
mockd import collection.json # Postman collections
mockd import recording.har # HAR files
mockd import wiremock-mapping.json # WireMock stubs
mockd import service.wsdl # WSDL → SOAP mocks
mockd import "curl -X GET https://api.example.com/users" # cURL commands
mockd export --format yaml > mocks.yaml
Cloud Tunnel
Share local mocks with your team instantly. All protocols routed through a single QUIC connection on port 443:
mockd tunnel enable
# → https://a1b2c3d4.tunnel.mockd.io → http://localhost:4280
Chaos Engineering
Test how your app handles failures:
# Apply a built-in chaos profile at startup
mockd serve --chaos-profile flaky --config mockd.yaml
# Or enable chaos at runtime
mockd chaos apply slow-api
Stateful Mocking
Simulate CRUD resources with automatic ID generation, pagination, and persistence. State is shared across protocols — REST and SOAP operate on the same data:
# mockd.yaml
statefulResources:
- name: users
basePath: /api/users
seedData:
- { id: "1", name: "Alice", email: "alice@example.com" }
mocks:
- type: soap
soap:
path: /soap/UserService
operations:
GetUser:
statefulResource: users # Same data as REST!
statefulAction: get
mockd serve --config mockd.yaml
# Create via REST
curl -X POST http://localhost:4280/api/users \
-d '{"name": "Bob"}' -H 'Content-Type: application/json'
# Retrieve via SOAP — same user!
curl -X POST http://localhost:4280/soap/UserService \
-H 'SOAPAction: GetUser' -H 'Content-Type: text/xml' \
-d '<soap:Envelope>...<GetUser><Id>...</Id></GetUser>...</soap:Envelope>'
Proxy Recording
Record real API traffic and replay it as mocks:
mockd proxy start --port 8888
# Configure your app to use http://localhost:8888 as proxy
# Traffic is recorded, then replay with:
mockd import recordings/session-name.json
Admin API
Full REST API for dynamic mock management at runtime:
# Create a mock
curl -X POST http://localhost:4290/mocks \
-H "Content-Type: application/json" \
-d '{"type":"http","http":{"matcher":{"method":"GET","path":"/health"},"response":{"statusCode":200,"body":"{\"status\":\"ok\"}"}}}'
# List mocks
curl http://localhost:4290/mocks
# Import OpenAPI spec
curl -X POST http://localhost:4290/import \
-H "Content-Type: application/x-yaml" \
--data-binary @openapi.yaml
Web Dashboard
Release builds include a built-in web UI served from the admin port:
mockd start
# Open http://localhost:4290 in your browser
Manage mocks for all 7 protocols visually with a VS Code-style tabbed editor, command palette (Ctrl+K), mock tree with search/sort/folders, request log viewer with near-miss debugging, and more. Docker images and all release packages include the dashboard automatically.
AI Mock Generation (MCP)
mockd includes a built-in Model Context Protocol server with 18 tools for full mock lifecycle management from AI-powered editors (Cursor, Windsurf, Claude Code):
mockd mcp # Start the MCP server (stdio transport)
Tools cover mock CRUD, import/export, chaos engineering (10 built-in profiles), mock verification, stateful resource management, custom operations, and multi-environment context switching.
Configuration
Configure via flags, environment variables, or config files:
# .mockdrc.yaml
port: 4280
adminPort: 4290
httpsPort: 5280
maxLogEntries: 1000
| Variable | Description | Default |
|---|---|---|
MOCKD_PORT | Mock server port | 4280 |
MOCKD_ADMIN_PORT | Admin API port | 4290 |
MOCKD_HTTPS_PORT | HTTPS port (0=disabled) | 0 |
MOCKD_CONFIG | Config file path |
Documentation
mockd.io — Full documentation, guides, and API reference.
Contributing
See CONTRIBUTING.md for development setup and guidelines.