Comprehensive API Mocking

Everything You Need for API Mocking

From simple stubs to complex enterprise scenarios. One tool that handles HTTP, GraphQL, gRPC, WebSocket, MQTT, SSE, and SOAP.

7 Protocols, One Tool

Stop juggling multiple mock servers. Mockd provides unified configuration across all major API protocols.

HTTP/REST

REST APIs, webhooks, and HTTP services

GraphQL

Queries, mutations, and subscriptions

gRPC

Protocol Buffers and microservices

WebSocket

Real-time bidirectional communication

MQTT

IoT messaging and pub/sub

SSE

Server-Sent Events for streaming

SOAP

Enterprise XML web services

Core Features

Powerful mocking capabilities that go beyond simple request/response matching.

Smart Request Matching

Scoring algorithm with 15+ matching criteria: path patterns, query params, headers, body content, JSONPath expressions, regex patterns, mTLS client identity, and more.

Dynamic Response Templating

35 built-in faker types (names, emails, credit cards, IBANs, IPs, and more), plus request variables, JSONPath extraction, regex captures, UUIDs, timestamps, sequences, seeded reproducible responses, and random data generation.

Record & Replay

MITM proxy captures real API traffic. Save as recordings, organize into sessions, and replay responses locally for deterministic testing.

Stateful Tables & Digital Twins

Config-defined tables with seed data, extend bindings for auto-wired CRUD, custom operations for business logic, and response transforms. Build digital twins of real APIs like Stripe and Twilio.

OAuth/OIDC Mock Provider

Built-in mock authorization server with token endpoints, JWKS, and user info. Test OAuth flows without a real identity provider.

OpenAI SSE Streaming

Mock OpenAI chat completion API with streaming responses. Build and test AI-powered apps without burning API credits.

mTLS Authentication

Client certificate verification with matching rules based on certificate fields. Secure mock endpoints with mutual TLS.

Prometheus Metrics

Built-in /metrics endpoint exposing request counts, latencies, and error rates. Ready for your existing monitoring stack.

OpenTelemetry Tracing

Distributed tracing support with span propagation. Trace requests through your mock server in complex microservice architectures.

Audit Logging

Comprehensive request/response logging to file or stdout. Built-in structured logging for debugging and compliance.

Chaos Engineering

10 built-in chaos profiles (slow-api, flaky, offline, mobile-3g, and more) plus custom latency, error rates, and bandwidth throttling. One command to simulate real-world failures.

OpenAPI Validation

Contract testing against OpenAPI/Swagger specs. Validate requests and responses match your API specification.

Loki Log Aggregation

Ship structured logs to Grafana Loki with the --loki-endpoint flag. Built-in batching and async flush for production-grade log collection.

Workspace Isolation

Organize mocks into isolated workspaces with independent state, request logs, and configuration. Run multiple API environments from a single mockd instance.

Rate Limiting Simulation

Simulate rate-limited APIs with token bucket and per-IP rate limiting for realistic API behavior testing.

Grafana Dashboards

Pre-built Grafana dashboards included for monitoring mock server performance and request patterns.

Enterprise Features

Enterprise-grade audit outputs, compliance tools, and premium support for organizations with advanced requirements.

Splunk HEC Audit Integration

Stream audit logs to Splunk via HTTP Event Collector for centralized enterprise log management and compliance.

Webhook Audit Output

Send audit events to custom webhook endpoints with configurable retry and exponential backoff.

Data Redaction

Automatically redact sensitive fields in logs and audit trails. Meet data privacy and compliance requirements.

Coming Soon

SSO/SAML Integration

Integrate with your existing identity provider. Support for Okta, Azure AD, OneLogin, and custom SAML providers.

Coming Soon

Role-Based Access Control

Granular permissions for teams. Control who can create, modify, and delete mock configurations across your organization.

Coming Soon

Custom SLA & Priority Support

Contractual response times, dedicated support engineer, and priority bug fixes for your organization.

Cloud Tunnel

Expose local mocks to the internet with one command. Share with teammates, test webhooks, demo APIs — all 7 protocols tunneled through a single secure connection.

Zero Config

No signup required. Run one command and get a public HTTPS URL instantly.

All Protocols

HTTP, GraphQL, gRPC, WebSocket, MQTT, SSE, and SOAP — all tunneled through a single connection.

Firewall Friendly

Multiplexed streams over a single secure connection on port 443. Works through firewalls and NAT without any configuration.

Tunnel Auth

Restrict access to your tunnel with authentication tokens. Control who can reach your mocks.

Single Port 443

Everything goes through port 443. Works behind corporate firewalls and restrictive networks.

Developer Experience

Use Mockd the way you want. CLI for scripting and automation, MCP server for AI-powered editors, or the API for full programmatic control.

CLI Interface

Full-featured command-line interface for scripting and automation

MCP Server

18-tool Model Context Protocol server with chaos engineering, circuit breaker control, mock verification, and stateful resource management. Works with Cursor, Windsurf, Claude Code, or any MCP-compatible editor.

Single Go Binary

No dependencies, no runtime. Just download and run (<30MB)

<10ms Startup

Start mocking instantly. No JVM warmup, no container spin-up

Works Offline

Fully local-first. No internet required, data stays private

Cloud Tunnel

Expose local mocks to the internet with one command. Share with teammates, test webhooks, demo APIs — all 7 protocols tunneled through a single secure connection.

AI-Native Mocking

The first API mocking tool with a built-in MCP server. Create, manage, and debug mocks directly from your AI-powered editor.

MCP Server — 18 Tools

Works with Cursor, Windsurf, Claude Code, and any MCP-compatible editor. Auto-starts a background daemon with zero setup — just add mockd mcp to your editor config. Pre-built agent config templates included.

Mock CRUD

  • Create, update, delete mocks
  • Toggle mocks on/off
  • Import & export configs

Chaos Engineering

  • 10 built-in chaos profiles
  • Latency, errors, bandwidth
  • Injection statistics

Verification

  • Assert call counts
  • Inspect invocation history
  • Reset between tests

Observability

  • Server health & stats
  • Request log inspection
  • Clear logs for test isolation

Stateful Tables & Digital Twins

  • Config-defined tables with seed data
  • Extend bindings auto-wire CRUD
  • Custom operations & response transforms
  • ID strategies: uuid, prefix, ulid, sequence, short
  • Delete resource & overview

Session Management

  • Context switching
  • Workspace isolation
  • Multi-environment workflows

AI Mock Generation

Describe your API in plain English and get production-quality mocks. Supports 4 AI providers with automatic prompt engineering.

# Generate mocks from a description
mockd generate --ai "e-commerce API with products, cart, and checkout"
# Enhance existing mocks with AI
mockd enhance --ai mockd.yaml
OpenAI
Anthropic
OpenRouter
Ollama (local)

Ready to Start Mocking?

Get started in under a minute. Single binary, no dependencies.

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