Handshake

Stop shipping
breaking changes.

Catch API drift before production. Upload your spec, spin up a mock server, and validate every PR automatically.

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Free forever for small teams · No credit card required

Features

Everything you need to shipwith confidence

Contract Versioning

Track every API change with automatic diff detection. Breaking changes are flagged instantly.

User API v2.1.0 → v2.2.0
-"role": { "type": "string" }
+"role": { "type": "string", "enum": ["admin", "user"] }
1 breaking change detected

Mock Servers

Generate realistic mock APIs from your contracts — hosted in the cloud or on your local machine with our CLI.

$ curl acme.mock.handshake.kumizhi-ai.com/users/1
{
"id": 1,
"name": "Jane Cooper",
"email": "jane@acme.co"
}
200 OK · 12ms · AI-enhanced data

CI Validation

Five lines of YAML. Every pull request validated against your contract. Breaking changes blocked before merge.

PR #142 — Update user endpoints
GET /users — 200 OK (45ms)
POST /users — 201 Created (89ms)
DELETE /users/:id — 404 Not Found
2 passed · 1 failed · blocked merge

Consumer Alerts & Approvals

Breaking changes trigger approval flows. Affected consumers review and approve before anything ships.

Breaking change detected

Field "role" removed from User schema

Review requested from @frontend-team

2 consumer apps affected

Approved

Safe to deploy

AI-Enhanced Mock Data

Claude generates realistic mock data for fields that faker.js can't handle — stock tickers, bios, dietary restrictions. Templates generated once per schema change, cached forever.

Before (faker.js)
"companyTicker": "a8xK2mP9qR"
After (AI-enhanced)
"companyTicker": "AAPL"

Local Mock Server

Run mock servers on your machine with a single command. No Docker, no cloud dependency. Your contracts, served locally with realistic data.

Offline supportCustom responsesWatch mode
# Install and start in seconds
npx @kumizhi/handshake-cli mock start
# Make requests against your mock
curl http://localhost:4010/api/users
{
"id": "a1b2c3",
"name": "John Smith",
"email": "john@example.com"
}

Pricing

Simple, transparent pricing

Start free. Scale when you're ready. Billed per Hub (your company workspace), not per seat.

Free

For individual developers exploring API contracts.

$0/mo

per Hub

  • 2 projects
  • 3 contracts
  • 100 CI runs/month
  • 1 team member
  • Mock servers
  • In-app & email alerts
Get Started

Pro

For small teams shipping APIs regularly.

$29/mo

per Hub

  • 10 projects
  • 25 contracts
  • 1,000 CI runs/month
  • 5 team members
  • Mock servers
  • AI inference
  • Slack & webhook alerts
Get Started

Recommended

Team

For engineering orgs that need full control.

$99/mo

per Hub

  • Everything in Pro, plus:
  • Unlimited projects & contracts
  • 10,000 CI runs/month
  • Unlimited members
  • Approval workflows
  • Consumer registry
  • All notification channels
Get Started

Enterprise

For organizations with specific requirements.

Custom
  • Everything in Team, plus:
  • Custom CI limits
  • SSO & SAML
  • Dedicated support
  • SLA guarantee
  • On-prem option
Contact Us

Stop breaking your APIs.

Be among the first engineering teams to ship without the fear of silent contract drift. Early access is open.

Get Started Free

Free forever for small teams · Setup in 5 minutes