Mockd

One binary. Seven protocols. Zero dependencies.

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.

Website · Docs · Samples · Contributing

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Quick Start

# 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}}

More install options

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

Pre-built binaries for Linux, macOS, and Windows on the Releases page.

Why mockd?

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

| | mockd | WireMock | Mockoon | Prism | MockServer | Beeceptor | json-server | |---|:---:|:---:|:---:|:---:|:---:|:---:|:---:| | Single binary, no runtime | ✅ | ❌ JVM | ❌ Electron | ✅ | ❌ JVM | ❌ SaaS | ❌ Node | | All 9 protocols built-in | ✅ | 🔌 Ext | Partial | HTTP only | HTTP only | Partial | REST only | | Chaos profiles + circuit breakers | ✅ | ⚠️ Cloud | ❌ | ❌ | ❌ | ❌ | ❌ | | MCP server | ✅ local | ⚠️ Cloud | ❌ | ❌ | ❌ | ⚠️ Cloud, Team+ | ❌ | | Free + self-hostable, unlimited | ✅ | ✅ | ✅ | ✅ | ✅ | 50 req/day | ✅ |

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

Full capability matrix (deployment, protocols, capabilities, imports/exports, pricing)

Deployment

| | mockd | WireMock | Mockoon | Prism | MockServer | Beeceptor | json-server | |---|:---:|:---:|:---:|:---:|:---:|:---:|:---:| | Native single binary | ✅ Go | ❌ | ❌ | ✅ | ❌ | ❌ | ❌ | | Runtime required | none | JVM | Electron/Node | optional Node | JVM | n/a (SaaS) | Node | | Docker image | ✅ | ✅ | ✅ CLI | ✅ | ✅ | ⚠️ Enterprise | ❌ | | Managed SaaS offering | roadmap | WireMock Cloud | Mockoon Cloud | Stoplight | ❌ | ✅ | ❌ |

Protocol support

| | mockd | WireMock OSS | Mockoon | Prism | MockServer | Beeceptor | json-server | |---|:---:|:---:|:---:|:---:|:---:|:---:|:---:| | REST / HTTP | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | | gRPC | ✅ | 🔌 Ext | ❌ | ❌ | ❌ | ✅ | ❌ | | GraphQL | ✅ | 🔌 Ext | ❌ | ❌ | ❌ | ✅ | ❌ | | WebSocket | ✅ | 🔌 Ext (beta) | ✅ | ❌ | ❌ | ❌ | ❌ | | MQTT | ✅ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | | SSE | ✅ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | | SOAP (WSDL) | ✅ | ❌ | Partial | ❌ | Partial | ✅ | ❌ | | mTLS | ✅ | ✅ | Partial | ❌ | ✅ | ✅ | ❌ | | OAuth flows | ✅ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |

Capabilities

| | mockd | WireMock OSS | Mockoon | Prism | MockServer | Beeceptor | json-server | |---|:---:|:---:|:---:|:---:|:---:|:---:|:---:| | Stateful CRUD | ✅ | ❌ | ✅ | Partial | ❌ | ✅ | ✅ | | Multi-step stateful flows | ✅ | ✅ Scenarios | Partial | ❌ | Partial | ✅ | ❌ | | Fault injection (delay, errors) | ✅ | ✅ | ✅ | ❌ | ✅ | ✅ | ❌ | | Chaos profiles | ✅ | ⚠️ Cloud | ❌ | ❌ | ❌ | ❌ | ❌ | | Circuit breakers | ✅ | ⚠️ Cloud | ❌ | ❌ | ❌ | ❌ | ❌ | | Bandwidth throttling | ✅ | ❌ | ❌ | ❌ | ❌ | roadmap | ❌ | | Admin REST API | ✅ | ✅ | CLI only | ❌ | ✅ | ✅ | Partial | | Built-in web dashboard | ✅ | ⚠️ Cloud | ⚠️ Cloud | ❌ | ✅ read-only | ✅ | ❌ | | Native desktop GUI | ❌ | ❌ | ✅ Electron | ❌ | ❌ | ❌ | ❌ | | MCP server | ✅ local | ⚠️ Cloud | ❌ | ❌ | ❌ | ⚠️ Cloud Team+ | ❌ | | Cloud tunnel sharing | ✅ | ❌ | ⚠️ Cloud | ❌ | ❌ | ✅ | ❌ |

Import / export

| | mockd | WireMock OSS | Mockoon | Prism | MockServer | Beeceptor | json-server | |---|:---:|:---:|:---:|:---:|:---:|:---:|:---:| | OpenAPI import | ✅ | ⚠️ Cloud | ✅ | ✅ | ✅ | ✅ | ❌ | | Postman import | ✅ | ⚠️ Cloud | ❌ | ✅ | ❌ | ❌ | ❌ | | HAR import | ✅ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | | WSDL import | ✅ | ❌ | ❌ | ❌ | ❌ | ✅ | ❌ | | cURL import | ✅ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | | WireMock format import | ✅ | native | ❌ | ❌ | ❌ | ❌ | ❌ | | Mockoon format import | ✅ | ❌ | native | ❌ | ❌ | ❌ | ❌ | | HAR export | ✅ | ✅ | ❌ | ❌ | ✅ | ✅ | ❌ |

Free tier limits

| | Requests | Mock rules | Cost | |---|---|---|---| | mockd | unlimited | unlimited | free (Apache 2.0) | | WireMock OSS | unlimited | unlimited | free (Apache 2.0) | | Mockoon desktop / CLI | unlimited | unlimited | free (MIT) | | Prism | unlimited | unlimited | free (Apache 2.0) | | MockServer | unlimited | unlimited | free (Apache 2.0) | | Beeceptor free tier | 50 / day / endpoint | 3 | $10/mo+ for more | | json-server | unlimited | unlimited | free (MIT) |

Legend: ✅ built-in • 🔌 Ext = separate OSS extension • ⚠️ Cloud = only in paid / hosted tier • Partial = limited implementation • roadmap = on the project's stated roadmap, not yet shipped

> Note on WireMock imports. The ⚠️ Cloud marks on OpenAPI and Postman import reflect first-party WireMock features. Community converters exist (e.g. openapi-to-wiremock, OpenAPI Generator targets) but are not bundled with the OSS standalone JAR.

Digital Twins

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.

AI-Native (MCP)

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.

Features

Multi-Protocol Mocking — 7 protocols, unified CLI

| 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 '' |

Import & Export — OpenAPI, Postman, HAR, WireMock, cURL, WSDL

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

Chaos Engineering — latency, errors, circuit breakers

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

Cloud Tunnel — share local mocks instantly

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

All 7 protocols multiplexed through a single secure connection on port 443. Works behind NAT and firewalls.

Workspaces — isolated mock environments

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

Proxy Recording — record real traffic, replay 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.json

Web Dashboard — manage mocks visually

Release builds serve a web UI from the admin port (http://localhost:4290). VS Code-style editor, command palette, mock tree with folders, request log viewer, and near-miss debugging.

Mockd Cloud

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.

Documentation

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

Contributing

Contributions welcome! See [CONTRIBUTING.md](CONTRIBUTING.md) for setup.

License

[Apache License 2.0](LICENSE) — free for commercial use.

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: getmockd
• Source: getmockd/mockd
• License: Apache-2.0
• Homepage: https://mockd.io

Install and usage instructions live in the source repository linked above.