Trust Layer is a proxy between your agents and the APIs they call. It fingerprints each request and response, signs the record, and anchors it with an independent timestamping authority and the Sigstore public log. An auditor can check those anchors without taking our word for it.
Free tier: 500 proofs a month, no credit card. Open source (MIT).
| Spec version | 3.1 |
|---|---|
| Issued | 2026-09-14T19:48:25Z |
| Upstream | corpus.arkforge.tech (HTTP 200) |
| Request hash | sha256:2058278a1e29e24e… |
| Response hash | sha256:387dcaed3079c39d… |
| Chain hash | sha256:842240b6d39d33b0… |
| Signature | ed25519:AVSK8y8_hafkhgLR… (ArkForge key) |
| Batch anchor | leaf 34 of 35, root sha256:1a575a9cde65… |
| RFC 3161 token | freetsa.org, on the batch root |
| Rekor log index | 2834496977, on the batch root |
Four steps. The first two happen while the call is in transit. The last two cover a batch of proofs and land within 10 minutes; each proof carries its path to the anchored batch root.
| Step | What happens | What it establishes | Checkable without ArkForge |
|---|---|---|---|
| 1. Fingerprint | SHA-256 of the request and the response. Each field gets its own commitment, and the chain hash is their Merkle root. | The record is internally consistent. | Yes, but on its own it proves little: a forged proof can be consistent too. |
| 2. Signature | Ed25519 signature over the chain hash, with ArkForge’s key published at /.well-known/did.json. |
ArkForge issued this proof. | No. It relies on ArkForge’s key. |
| 3. Timestamp | The batch root is sent to an RFC 3161 authority: FreeTSA, with DigiCert and Sectigo as fallbacks. | The proof existed at that time. | Yes, with the authority’s certificate. |
| 4. Public log | The batch root is recorded in Sigstore Rekor, an append-only log run under the Linux Foundation. | The record was published at that time and has not been rewritten since. | Yes, on rekor.sigstore.dev. |
Until its batch closes, a proof carries steps 1 and 2 only, so ArkForge alone vouches for it during that window.
A log proves you recorded something. It is written by the party whose conduct is in question, on a clock that party controls.
These limits are part of the specification. Read them before you rely on a proof.
Send the call to the proxy with the target URL and the payload. The upstream response comes back with the proof next to it.
curl -X POST https://trust.arkforge.tech/v1/proxy \
-H "X-Api-Key: $ARKFORGE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"target": "https://api.example.com/v1/run",
"payload": {"task": "analyze", "text": "hello"}
}'
{
"service_response": {
"status_code": 200,
"body": { … }
},
"proof": {
"proof_id": "prf_20260914_194825_a747d0",
"spec_version": "3.1",
"hashes": { "request": …, "response": …, "chain": … },
"arkforge_signature": "ed25519:…",
"batch_anchor": { "status": "pending" },
"verification_url": "https://trust.arkforge.tech/v1/proof/…"
}
}
To check a proof yourself, run the standalone verifier (Python standard library and openssl): python3 verify_proof.py prf_20260914_194825_a747d0. How verification works.
CISOs, DPOs and legal teams at EU-regulated companies who need records of AI system behaviour for internal audits, regulatory requests or contractual disputes.
Each anchored proof carries an RFC 3161 token and a Rekor log index that an auditor checks directly with those services. Keep the proof JSON with your records: those two anchors remain checkable even if ArkForge stops operating.
The free tier includes 500 proofs a month. Integration is one HTTP call per request: no SDK, no new dependency, no agent rewrite.
Trust Layer is not tied to a model or a provider. It certifies calls to OpenAI, Anthropic, Mistral, internal APIs and any HTTP endpoint in the same chain.
500 proofs a month, no credit card. Paid plans from €29 a month.