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

---

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.

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

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

Deployment

Protocol support

Capabilities

Import / export

Free tier limits

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

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

</details>

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

</details>

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

</details>

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

</details>

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](https://docs.mockd.io).

Contributing

Contributions welcome! See CONTRIBUTING.md for setup.

License

Apache License 2.0 — free for commercial use.