Pay-per-call eSignature + ID verification. $0.10 per call.
Send a contract for signature, or verify an ID, in one HTTPS call. $0.10 per call — for both. Pay per use; no subscriptions, no minimums. Built for developers and AI agents: x402 per-call payment, MCP discovery, OpenAPI 3.1, llms.txt.
curl -X POST https://api.verafirma.com/v1/envelopes \
-H "PAYMENT-SIGNATURE: $(cat payment.b64)" \
-F 'pdf=@contract.pdf' \
-F 'payload={"title":"NDA","recipients":[{"email":"x@example.com","name":"X","role":"SIGNER"}]}'
Pay per call
$0.10 per envelope. No minimum. No commitment. Use it once and never come back; never get billed for nothing.
ID verification too
Same $0.10 price. Same one-call API. Verify a customer's ID without the ID.me bundle — no AML scoring, no enterprise compliance overhead, just the part you actually wanted.
Learn more →Agent-native
OpenAPI 3.1, MCP discovery, llms.txt, .md doc twins, audience-tagged surfaces. Built for programs, not just for humans clicking dashboards.
Pricing in one line
$0.10 per envelope. Pay per call — no minimum, no commitment. Refunded automatically on terminal failure (rejected, expired, cancelled) up to a per-envelope cap.
See the per-mode breakdown →Discover the API
- Quickstart — five-line curl from PDF + recipient + payment to signing URL.
- The lodestone path — design rationale for the canonical agent use case.
- x402 wire format — EIP-3009 per-call payment authorization.
- MCP — point an MCP-compatible
client at
https://api.verafirma.com/mcp. - API reference — audience-augmented OpenAPI 3.1 surface.
- llms.txt + llms-full.txt — agent-friendly discovery surfaces.