# imgauth — API di attestazione opere digitali

> Digital-work attestation and proof-of-existence service operated by Spazio Genesi ETS, an Italian
> non-profit. The client computes a SHA-256 fingerprint locally and sends only the 64-hex hash — file
> bytes never leave the device. The service binds the fingerprint to a server-side timestamp, signs it
> (HMAC), issues a PAdES B-LT signed PDF certificate carrying an RFC 3161 timestamp, and anchors the
> fingerprint in Bitcoin through OpenTimestamps across four calendars. Verification is free and unlimited
> for anyone, and the proof of existence never expires. The service positions itself explicitly as a
> NON-QUALIFIED attestation under eIDAS 2.0. The API contract is in Italian by design — do not translate
> the field names. Generated by API Evangelist from the provider's published contract and docs; the
> provider does not serve an llms.txt of its own (2026-08-11).

## APIs

- [imgauth REST API](https://imgauth.spaziogenesi.org): 18 operations, OpenAPI 3.0.3, engine 1.34.1. Attestation, verification, certificate retrieval, OpenTimestamps proofs, embeddable badges, public status telemetry and the agent device flow.
- [imgauth Remote MCP Server](https://attest-mcp-remote.it-e3f.workers.dev/mcp): hosted Streamable HTTP MCP server, protocol 2025-06-18, 8 tools. Four are public (service_status, check_anchor, verify_attestation, lookup_certificate); four need a credential (authorize, complete_authorization, attest_hash, create_certificate_pdf).

## Specs

- [OpenAPI 3.0.3](https://imgauth.spaziogenesi.org/openapi.json): the live contract, served from the API host root.
- [security.txt](https://imgauth.spaziogenesi.org/.well-known/security.txt): RFC 9116, served on the API and docs hosts.

## Docs

- [Developer documentation](https://attestazione.spaziogenesi.org/en/developer/): auth, tiers, MCP, CLI, GitHub Action.
- [Interactive API reference](https://attestazione.spaziogenesi.org/docs/): Swagger UI with try-it-out.
- [CLI](https://attestazione.spaziogenesi.org/en/developer/cli/): sg-attest, npx or standalone binaries for six platforms.
- [API keys](https://attestazione.spaziogenesi.org/en/developer/keys/): self-service issuance after email verification.
- [Changelog](https://attestazione.spaziogenesi.org/changelog/): dated, Italian and English.
- [Status](https://attestazione.spaziogenesi.org/status/): 90-day history, backed by three public JSON endpoints.
- [Security policy and responsible disclosure](https://attestazione.spaziogenesi.org/sicurezza/)
- [Trust Center](https://trust.spaziogenesi.org/): compliance map, ADRs, subprocessors, open Trust Score.
- [Terms and tiers](https://attestazione.spaziogenesi.org/en/condizioni/): retention guarantees per tier.
- [Integrations showcase](https://attestazione.spaziogenesi.org/integrazioni/)

## How an agent should use this

- Compute the SHA-256 locally (`sha256sum <file>`). NEVER pass file bytes or base64 as tool arguments — the server does not accept them on the agent path.
- Verification needs no credential. Attestation does: run the device flow (`authorize`, then `complete_authorization`) or send `Authorization: Bearer sg_k_...`.
- A credential only bypasses the anti-bot challenge and applies your tier quota. Per-IP rate limits (60/60s, and 10/60s on certificate PDF generation) apply either way.
- There is no idempotency key. Re-posting the same fingerprint issues a NEW attestation; retrieval resolves the oldest. Do not blind-retry a timed-out attestation.
- Errors return `{"error": "<string>"}` — branch on the HTTP status, not on the message.
- Declared metadata (titolo, autore, anno, note) is bound into the signature. To verify later, resupply all fields exactly as printed.

## Source

- [GitHub — imgauth engine (AGPL-3.0)](https://github.com/SPAZIO-GENESI/imgauth)
- [GitHub — remote MCP server (MIT)](https://github.com/SPAZIO-GENESI/attest-mcp-remote)
- [npm — @spazio-genesi/attest-mcp](https://www.npmjs.com/package/@spazio-genesi/attest-mcp): MCP server + sg-attest CLI, v0.4.1 (2026-07-24).
- [GitHub Action — attest-action](https://github.com/SPAZIO-GENESI/attest-action)