API Development MCP Servers for Claude Desktop

Register an event callback address.

Find and call verified APIs from any AI assistant, with free trial calls and previewed writes.

Validate emails, phones, IBAN, VAT; look up IPs and companies; rates, holidays, time via Abstract.

Verified, reproduced behavior of public HTTP APIs: spec gaps, errors, pagination, auth.

Webhook, email and DNS inboxes for AI agents to capture callbacks and test integrations.

Evidence-cited machine-readable contracts for how agent platform APIs really behave