PostalForm A2A Agent
Agent2Agent (A2A) surface: an agent card served from https://postalform.com/.well-known/agent-card.json (protocolVersion 1.0, JSONRPC binding, version 0.1.0, a2a-version: 1.0 response header) advertising three guidance skills — connect an agent to PostalForm MCP, plan a reviewable mail draft, plan an authorized machine-paid order — with x402 and UCP discovery documents declared as capability extensions. The declared JSON-RPC endpoint https://postalform.com/a2a returns the card on GET and answers tasks/get with -32601 Method not found; the provider calls it a discovery bridge, and the executable surface is the MCP server the card points at.