mockd

io.mockdPublished by mockd.iov0.4.6Updated Oct 24, 2026

Multi-protocol API mock server: HTTP, GraphQL, gRPC, WebSocket, MQTT, SSE, SOAP.

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Server details

Identifier: io.mockd/mockd
Transport: STDIO
Runtime: Desktop only
Trust: Verified
Published: Sep 16, 2026

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Overview

AI-generated overview

mockd is a local multi-protocol API mock server whose built-in MCP server lets an assistant create mocks, manage stateful data, inject faults and verify request

What you can do: Create, update and delete mocks across HTTP, gRPC, GraphQL, WebSocket, MQTT, SSE and SOAP from a single local server. Manage stateful resources and multi-step flows so mocks behave like a real CRUD API. Import and export specs and recordings from OpenAPI, Postman, HAR, WSDL, WireMock and cURL. Apply chaos profiles, fault injection and circuit breakers, then inspect request logs and verify contracts. Organize mocks into isolated workspaces and share them through a cloud tunnel.
When to use it: Useful when you are building or testing a client against an API that does not exist yet, is unreliable, or costs money to call, and you want an assistant to stand up and adjust mocks directly. Also fits contract verification and fault-injection testing across several protocols.
Requirements: Runs as a local process on the user's machine, started with the mockd binary and the mcp argument; the binary is distributed as a container image, Homebrew formula, Go install or pre-built binary. No account, API key or environment variable is declared, and it works fully offline.

Before you install

The assistant can create, change and delete mocks, stateful data and workspaces, and can start servers that listen on local ports. Chaos profiles deliberately inject errors and latency. The optional cloud tunnel exposes local mocks through a public URL, so review what is shared before enabling it.

Installation

In SourceWeft

Open mockd in the dashboard and add it to a workspace.
Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

[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.

[CI] [Release] [Stars] [Go] [License]

Website · Docs · Samples · Contributing

[mockd demo]

Quick Start

bash

# Installcurl -sSL https://get.mockd.io | sh
# Start + create a stateful CRUD API in one commandmockd startmockd add http --path /api/users --stateful users
# It works immediatelycurl -X POST localhost:4280/api/users -d '{"name":"Alice","email":"[email protected]"}'# → {"id":"a1b2c3","name":"Alice","email":"[email protected]"}
curl localhost:4280/api/users# → {"data":[{"id":"a1b2c3","name":"Alice","email":"[email protected]"}],"meta":{"total":1}}

# Installcurl -sSL https://get.mockd.io | sh
# Start + create a stateful CRUD API in one commandmockd startmockd add http --path /api/users --stateful users
# It works immediatelycurl -X POST localhost:4280/api/users -d '{"name":"Alice","email":"[email protected]"}'# → {"id":"a1b2c3","name":"Alice","email":"[email protected]"}
curl localhost:4280/api/users# → {"data":[{"id":"a1b2c3","name":"Alice","email":"[email protected]"}],"meta":{"total":1}}

More install options

bash

brew install getmockd/tap/mockd                                          # Homebrewdocker run -p 4280:4280 -p 4290:4290 ghcr.io/getmockd/mockd:latest      # Dockergo install github.com/getmockd/mockd/cmd/mockd@latest                    # Go

brew install getmockd/tap/mockd                                          # Homebrewdocker run -p 4280:4280 -p 4290:4290 ghcr.io/getmockd/mockd:latest      # Dockergo 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:

yaml

# mockd.yaml — Stripe digital twinversion: "1.0"imports:  - path: stripe-openapi.yaml    as: stripetables:  - name: customers    idStrategy: prefix    idPrefix: "cus_"    seedData:      - { id: "cus_1", name: "Acme Corp", email: "[email protected]" }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.yaml — Stripe digital twinversion: "1.0"imports:  - path: stripe-openapi.yaml    as: stripetables:  - name: customers    idStrategy: prefix    idPrefix: "cus_"    seedData:      - { id: "cus_1", name: "Acme Corp", email: "[email protected]" }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 }

bash

mockd start -c mockd.yaml --no-authcurl -X POST localhost:4280/v1/customers -d "name=Test&[email protected]"# → {"id":"cus_a1b2c3","object":"customer","name":"Test","email":"[email protected]"}

mockd start -c mockd.yaml --no-authcurl -X POST localhost:4280/v1/customers -d "name=Test&[email protected]"# → {"id":"cus_a1b2c3","object":"customer","name":"Test","email":"[email protected]"}

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:

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 '<OK/>'`

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

bash

mockd import openapi.yaml           # OpenAPI 3.x / Swagger 2.0mockd import collection.json        # Postman collectionsmockd import recording.har          # HAR filesmockd import wiremock-mapping.json  # WireMock stubsmockd import service.wsdl           # WSDL → SOAP mocksmockd import "curl -X GET https://api.example.com/users"  # cURL commandsmockd export --format yaml > mocks.yaml

mockd import openapi.yaml           # OpenAPI 3.x / Swagger 2.0mockd import collection.json        # Postman collectionsmockd import recording.har          # HAR filesmockd import wiremock-mapping.json  # WireMock stubsmockd import service.wsdl           # WSDL → SOAP mocksmockd import "curl -X GET https://api.example.com/users"  # cURL commandsmockd export --format yaml > mocks.yaml

Chaos Engineering — latency, errors, circuit breakers

bash

mockd chaos apply flaky       # 30% error ratemockd chaos apply slow-api    # 200-800ms latencymockd chaos apply offline     # 100% 503 errorsmockd chaos disable

mockd chaos apply flaky       # 30% error ratemockd chaos apply slow-api    # 200-800ms latencymockd chaos apply offline     # 100% 503 errorsmockd chaos disable

Cloud Tunnel — share local mocks instantly

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

Workspaces — isolated mock environments

bash

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

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

Proxy Recording — record real traffic, replay as mocks

bash

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 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 for setup.

License

Apache License 2.0 — free for commercial use.

Source: README.md at commit 45c2906

Tools

SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

v0.4.6LatestSep 16, 2026

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