API-first domain registration

Base URLs & authentication

Sandbox     https://sandbox.api.fairverra.com/v1      (fv_test_ keys, simulated registrar, Mollie test mode)
Production  https://api.fairverra.com/v1   (fv_live_ keys, self-service)

Authorization: Bearer fv_test_...

Sandbox keys are free and self-service (see the quickstart). The sandbox runs the full product flow against a simulated registrar: no real registrations, no real money. Production is self-service too: signup → verify → billing details (PUT /me/billing) → accept the legal documents (terms, privacy, registration agreement) → first wallet deposit → POST /keys/upgrade issues the full key. The API contract is identical to the sandbox.

Endpoints

Paths below are relative to the base URL. The OpenAPI spec is the authoritative contract, including all request/response schemas and the stable error-code enum.

Rules every client can rely on

• No silent charges. Money only moves on an explicit confirm of a quote that shows the exact price — premium domains included.
• Dollar labels on request. Pass currency: "USD" on check (works keyless) or ?currency=USD on the catalog. prices stay EUR; presentment is the dollar amount. The wallet stays EUR. Never convert FX yourself.
• Stable error codes. Every error is { "error": "...", "code": "STABLE_CODE" }; texts may change, codes never do.
• Registrar-independent. The contract never leaks registrar internals; switching our upstream registrar does not change /v1.
• Idempotency. Quotes accept an idempotency_key; replays return the original result, conflicting replays get 409 IDEMPOTENCY_CONFLICT.
• Versioned. /v1 is frozen once complete; breaking changes only in /v2 with a generous overlap period.

MCP server (for AI agents)

The same API is available as a remote MCP server, so agents in Cursor, Claude and other MCP clients can use it directly — tools for checking, quoting, confirming, wallet, contacts, DNS, DNSSEC, legal accept and key upgrade. One-click install: fairverra.com/ai. check_domain and list_extension_pricing accept optional currency: "USD" for dollar labels. The wallet stays EUR.

Claude Code plugin

The Fairverra plugin wraps the remote MCP server with skills such as "register a domain and connect it to this project". It points at production https://api.fairverra.com/mcp and uses the same OAuth sign-in.

claude plugin marketplace add gerbenlive/fairverra-claude-plugin
claude plugin install fairverra@fairverra

From a checkout: claude --plugin-dir ./plugins/fairverra. Skills: /fairverra:register-and-connect-domain, /fairverra:transfer-domain, /fairverra:manage-dns.

Claude (claude.ai, Claude Desktop)

Use Add to Claude or paste https://api.fairverra.com/mcp as a custom connector. Claude discovers our OAuth flow automatically: you sign in with your email address and a one-time code — no API key needed. Sandbox (no real registrations): https://sandbox.api.fairverra.com/mcp.

Cursor and other MCP clients

One-click: Add to Cursor. Or the same OAuth URL, or an API key:

{
  "mcpServers": {
    "fairverra": {
      "type": "http",
      "url": "https://api.fairverra.com/mcp"
    }
  }
}

Paid actions keep the quote → confirm split as separate tools: create_quote shows the price, confirm_approval is documented to require explicit human approval first. Legal acceptances use accept_legal_documents the same way: show the three document URLs from whoami, then call only after an explicit yes. That records terms, privacy and the registration agreement. POST /me/accept-terms is terms-only and is not enough on production.