Mock HTTP, gRPC, GraphQL, WebSocket, MQTT, SSE, and SOAP from a single CLI tool.
Import OpenAPI specs. Build digital twins. Let AI agents create mocks for you.

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# Install
curl -sSL https://get.mockd.io | sh

# Start + create a stateful CRUD API in one command
mockd start
mockd add http --path /api/users --stateful users

# It works immediately
curl -X POST localhost:4280/api/users -d '{"name":"Alice","email":"alice@test.com"}'
# → {"id":"a1b2c3","name":"Alice","email":"alice@test.com"}

curl localhost:4280/api/users
# → {"data":[{"id":"a1b2c3","name":"Alice","email":"alice@test.com"}],"meta":{"total":1}}

brew install getmockd/tap/mockd                                          # Homebrew
docker run -p 4280:4280 -p 4290:4290 ghcr.io/getmockd/mockd:latest      # Docker
go install github.com/getmockd/mockd/cmd/mockd@latest                    # Go

Every other mock tool makes you choose: pick one protocol, install a runtime, bolt on extensions. mockd doesn't.

🔌 Ext = requires separate extension JAR • ⚠️ Cloud = only in paid/hosted tier

Import a real API spec, bind it to stateful tables, and get a mock that passes the real SDK:

# mockd.yaml — Stripe digital twin
version: "1.0"
imports:
  - path: stripe-openapi.yaml
    as: stripe
tables:
  - name: customers
    idStrategy: prefix
    idPrefix: "cus_"
    seedData:
      - { id: "cus_1", name: "Acme Corp", email: "billing@acme.com" }
extend:
  - { mock: stripe.GetCustomers, table: customers, action: list }
  - { mock: stripe.PostCustomers, table: customers, action: create }
  - { mock: stripe.GetCustomersCustomer, table: customers, action: get }
  - { mock: stripe.PostCustomersCustomer, table: customers, action: update }
  - { mock: stripe.DeleteCustomersCustomer, table: customers, action: delete }

mockd start -c mockd.yaml --no-auth
curl -X POST localhost:4280/v1/customers -d "name=Test&email=test@corp.com"
# → {"id":"cus_a1b2c3","object":"customer","name":"Test","email":"test@corp.com"}

Validated with real SDKs:

• Stripe: 49/49 stripe-go SDK tests pass
• Twilio: 13/13 twilio-go SDK tests pass
• OpenAI: openai Python SDK verified (models, assistants, chat completions)

See mockd-samples for complete digital twin configs.

mockd includes a built-in Model Context Protocol server with 18 tools. AI agents can create mocks, manage state, import specs, and verify contracts without touching the CLI:

{
  "mcpServers": {
    "mockd": { "command": "mockd", "args": ["mcp"] }
  }
}

Works in Claude Desktop, Cursor, Windsurf, and any MCP-compatible editor. Tools cover mock CRUD, stateful resources, chaos injection, request logs, verification, workspaces, and import/export.

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

mockd chaos apply flaky       # 30% error rate
mockd chaos apply slow-api    # 200-800ms latency
mockd chaos apply offline     # 100% 503 errors
mockd chaos disable

mockd tunnel
# → https://a1b2c3d4.tunnel.mockd.io → http://localhost:4280

mockd workspace create -n "Payment API" --use
mockd import stripe-openapi.yaml
mockd workspace create -n "Comms API" --use
mockd import twilio-openapi.yaml
# Mocks, state, and logs are fully isolated per workspace

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.json

mockd works fully offline with no account required. For teams that want shared environments:

• Persistent cloud mocks — deploy mock environments your whole team can hit
• Team management — shared workspaces with access controls
• Cloud tunnels — authenticated tunnels with custom domains

Coming soon. Join the waitlist.

Full guides, API reference, and config docs at docs.mockd.io.

Contributions welcome! See CONTRIBUTING.md for setup.

Apache License 2.0 — free for commercial use.