Verifying Provider Profile

agent-safe.verifying-provider/1, version 0.2, status draft. Section 7, the effect receipt, is normative as of this version: the Decionis OpenAPI document carries it, the executor forwards it, and five implementations build one from the same vectors.

A system of record is the only party that can refuse an instruction rather than merely fail to receive it. Bypass resistance ranks the three chokepoints an execution boundary has, the provider refusing, the credential the agent never holds, and the network, and says why the first is the one worth insisting on. This profile is that first chokepoint written down as something a provider can implement and claim: the exact procedure by which a system of record, or the last hop in front of it that its owner controls, establishes that a request came from the executor holding a key it issued, that the authority claimed a single-use grant for this exact intent over these exact parameters, and that the grant has not been used before, and refuses, effecting nothing, otherwise.

Nothing here is new to the executor. The procedure is the one @decionis/agentsafe documents for its SIGNED_REQUEST credential and the one the offline proof's strict provider double runs. What is new is that it is stated once, normatively, with test vectors any implementation can run, so that native verification is a place a verifier is deployed rather than a product a vendor ships. A customer moves from an executor-only boundary, to a verifying hop, to a verifying system of record without changing agents, policies or evidence.

The key words MUST, MUST NOT, SHOULD, MAY are to be read as in RFC 2119.

1. Where a verifier runs

A hop at the second tier is a verifying provider in this profile's sense only when the system of record admits no other principal: the hop holds the system's sole credential, and the system is reachable by nothing else, whether by mutual TLS to a certificate only the hop has, or by a private link whose route exists only in the hop's namespace. Otherwise the hop is a network control, and bypass resistance says what those are worth. Passing this profile's vectors demonstrates the procedure; the tier's conditions are the operator's.

2. Terms

• Authority: Decionis, or an implementation of its protocol, that evaluates an intent, issues a grant on ALLOW, and attests to the claim of that grant. Its execution-grant keys are published at /.well-known/decionis-execution-grant-jwks.json on its API origin: https://api.decionis.com/.well-known/decionis-execution-grant-jwks.json for Decionis.
• Executor: the process that captured the intent, claimed the grant, and dispatches the request: @decionis/agentsafe, or an adopter's process built on it. It signs each dispatch with a key the provider knows by keyid.
• Provider: the party running this procedure: the system of record, or the owner-controlled hop in front of it.
• Intent hash: sha256: over the RFC 8785 canonical form of the agent-safe.intent/1 binding (execution binding). What every later record names.
• Grant: the single-use authorization the authority issued with an ALLOW. Claim: the executor's atomic consumption of it immediately before dispatch (claim and finalize). Lease: the interval after the claim within which the dispatch must happen; the attestation expires with it.
• Attestation: the compact JWS the authority returns with a live claim (claim_attestation, schema ClaimAttestationClaims, in the Decionis OpenAPI document), which the executor forwards under x-agent-safe-claim-attestation and signs over. It is issued only once the authority has atomically consumed the grant: it is the authority's proof that the claim happened, and it is not the grant.
• Effecting request: one that changes state at the system of record. A read that changes nothing may be verified at VP-1 alone.

3. Conformance levels

• VP-1, signed request. The provider verifies the executor's HTTP message signature (RFC 9421) with its content digest (RFC 9530) and requires the covered components section 5 names. A provider at VP-1 refuses anything the executor did not send. It does not know whether the authority claimed anything.
• VP-2, attested claim. VP-1, and the provider verifies the authority's attestation against the authority's published keys, checks that the request in hand is the one the attestation describes (grant, decision, intent hash, canonical parameter digest, expiry), and refuses a second presentation of the grant within the lease. A provider at VP-2 refuses what the authority never claimed. This is the level a system of record needs.
• VP-3, effect receipt. VP-2, and the provider signs what it effected, or refused, keyed by the grant and the claim, and returns it with its answer, so the effect plane becomes provider-attested rather than executor-reconciled. Section 7.

The invariant behind the levels, stated so that it cannot be misread: verification proves what the authority issued; the authority's claim is what consumes it; only the attestation of that claim, bound to this request, permits the provider to effect. A grant, a decision or a dossier that a provider verified by signature alone MUST NOT, by itself, authorize an effect. Offline verification, @decionis/verify included, is deliberately stateless and cannot know whether a valid grant was consumed; a provider that effects on verify(grant) alone is replayable by construction.

An implementation claims a level by passing every vector at that level in conformance/provider and stating the level and the profile version (section 8).

4. What the provider receives

The executor's own reference for what it sends is packages/agentsafe/README.md, "Downstream credentials". For a dispatch:

The eight components this profile knows, in the order the executor lists them: @method, @path, content-digest, idempotency-key, x-agent-safe-intent-hash, x-agent-safe-grant-id, x-agent-safe-decision-id, x-agent-safe-claim-attestation. The first five are the base. @path is the request path without its query. Any other header the executor sends, such as x-agent-safe-dossier-id, is not covered and MUST NOT influence whether the provider effects.

5. Procedure

Normative, in this order. The first failing step names the refusal, and a refusal effects nothing.

Step 0, parse. From signature-input, take the text after agentsafe= as the parameters. From signature, take the base64 between the colons after agentsafe=. Either header absent, or not of that form, is SIGNATURE_INVALID_OR_INCOMPLETE.

Step 1, content digest. Compute sha-256=:<base64(SHA-256(body))>: over exactly the bytes received, the empty body included, and compare it with content-digest byte for byte. A difference is SIGNATURE_INVALID_OR_INCOMPLETE.

Step 2, covered components. The parameters begin with a parenthesised, space-separated list of quoted component names. Every name MUST be one of the eight, none repeated. The base MUST be present. A provider that effects MUST require all eight; a provider verifying a read that effects nothing MAY require the base alone. Any requirement unmet is SIGNATURE_INVALID_OR_INCOMPLETE. A request may carry a grant header the signature does not cover; such a header proves nothing about the grant, which is why the requirement is on the covered list and not on the headers present.

Step 3, freshness. created MUST lie within a window of the provider's clock. The window is the provider's; it SHOULD be no more than 300 seconds each way. Outside it is SIGNATURE_INVALID_OR_INCOMPLETE.

Step 4, key. keyid MUST name a key the provider issued to, or registered for, the executor, and alg MUST be that key's algorithm: ed25519 for an Ed25519 public key, hmac-sha256 for a shared secret. An unknown key, or an algorithm the key is not for, is SIGNATURE_INVALID_OR_INCOMPLETE. Section 10 says what a shared secret costs.

Step 5, signature base and verification. Build the base as one line per covered component, in the order the list gives them, then the parameters line:

"@method": <the method, upper case>
"@path": <the request path, without its query>
"content-digest": <the content-digest value>
"idempotency-key": <the header value>
"x-agent-safe-intent-hash": <the header value>
"x-agent-safe-grant-id": <the header value>
"x-agent-safe-decision-id": <the header value>
"x-agent-safe-claim-attestation": <the header value>
"@signature-params": <the parameters, verbatim>

Lines are joined by a single line feed, with no trailing line feed. Each header value is the value received, exactly; a covered header that is absent, or present more than once, is SIGNATURE_INVALID_OR_INCOMPLETE. Verify the signature over the UTF-8 bytes of the base: Ed25519 against the key, or HMAC-SHA256 compared in constant time and only at its full length. A failure is SIGNATURE_INVALID_OR_INCOMPLETE. A read verified at VP-1 alone ends here.

Step 6, attestation form. Split x-agent-safe-claim-attestation on . into exactly three base64url parts. Decode the first as a JSON object: alg MUST be EdDSA, typ MUST be decionis-claim-attestation+jwt, and kid MUST name a key in the authority's execution-grant JWKS (section 9 says how to hold that document). Verify the Ed25519 signature, the third part, over the ASCII bytes of the first part, a dot, and the second part, with that key. Decode the second part as a JSON object, the claims. It MUST carry strings iss, sub, decision_id, dossier_id, claim_token_digest and jti, a number exp, and an object binding with strings intent_hash, execution_payload_digest and execution_payload_canonicalization_profile: the claims step 7 compares and the ones a receipt (section 7) is built from; an attestation without them is not one. iss MUST equal the issuer of the authority the provider trusts, https://decionis.com for Decionis. Any failure is ATTESTATION_INVALID.

Step 7, the attestation describes this request. All of the following MUST hold, else the refusal is ATTESTATION_DOES_NOT_DESCRIBE_THIS_REQUEST:

• sub equals x-agent-safe-grant-id;
• decision_id equals x-agent-safe-decision-id;
• binding.intent_hash equals x-agent-safe-intent-hash;
• binding.execution_payload_canonicalization_profile equals RFC8785/JCS, the one profile this version defines;
• binding.execution_payload_digest equals sha256: followed by the lower-case hex of SHA-256 over the RFC 8785 canonical form of the body parsed as JSON. The body MUST be a JSON object, since parameters are one, and it MUST be I-JSON (RFC 7493): no lone surrogates, no non-finite numbers, no duplicate names; anything else is refused under this same code, and so is a request with no body, which describes no parameters. The provider MUST canonicalise, never hash the raw bytes: step 1 bound the bytes the executor sent, this step binds the parameters the authority saw, and the two need not be the same bytes;
• exp, in seconds since the epoch, is later than now.

A provider that effects for more than one organisation SHOULD also require org_id to be the organisation this endpoint effects for. nbf MAY be checked, with the step 3 window.

Step 8, single presentation. The provider keeps sub until exp. If sub was recorded by an earlier acceptance, the refusal is GRANT_REPLAYED. Otherwise the provider records it before effecting. The record MUST be visible to every instance that could effect this grant within the lease: the executor never retries a side effect, so a second presentation is never the executor. This step is not a second single-use authority. The grant was consumed once, at the authority, when the attestation was issued; the step guards the one thing an attestation cannot, a second presentation of that one consumption inside its lease, which is why the record needs no life beyond exp.

Accept. Effect exactly once and answer 2xx. A provider at VP-3 answers with its receipt (section 7), on a 2xx and on a 4xx of its own alike.

Refuse. Effect nothing and answer 4xx, 409 in the reference implementations, with the body {"status":"REJECTED","reason_code":"<code>"}. A refusal MUST NOT be a 5xx: the executor reads 4xx as DEFINITELY_NOT_EXECUTED and finalizes FAILED, and 5xx as UNKNOWN_AFTER_DISPATCH (execution outcomes). The response MUST NOT echo the body or the attestation.

6. What each level guarantees

VP-1. The request was sent by the holder of the named key, for this intent hash, with this body. A copied set of headers, an altered body, or an altered covered header proves nothing.

VP-2. The authority claimed this grant, for this intent, over these canonical parameters, within a lease that has not ended, and this is the first use. A compromised executor can sign a request; it cannot attest to one, because the attestation key is not in the executor. A leaked attestation cannot be presented again inside the lease, and never carried the claim token, only its digest, so it finalizes nothing. Together: no instruction effects at the provider that the authority did not claim for exactly these parameters, which is the property the first row of the bypass-resistance table names.

What VP-2 does not give. That the effect matched the parameters. The provider is trusted for that; the executor's effect plane (BEAP conformance) reconciles its observation afterwards.

VP-3. The party that effected says what it effected, under its own signature, bound to the grant it effected it under and to the claim it answered, and the authority records that statement with the commit. A dossier at VP-3 carries the provider's signature over the effect, not only the executor's report of it, and when the grant named the effect it expected, a receipt whose digest agrees confirms the effect by the provider's key.

7. Effect receipt (VP-3)

The attestation lets the provider refuse what the authority never claimed. The receipt closes the other direction: after effecting, or refusing, a request it accepted at step 8, the provider signs what it did, bound to the grant it acted under and the claim it answered, and the authority records it with the commit. Until this existed, the exactly-once and the effect were the executor's word, checked by reconciliation; with it, the party that effected says so.

The contract's source of truth is the Decionis OpenAPI document: the schema EffectReceiptClaims, the effect_receipt field of ExecutionFinalizeRequest and ExecutionFinalizeResponse, and the operations under /v1/execution/provider-keys. This section states what a provider does.

Key. The provider signs receipts with an Ed25519 key of its own. The organisation registers the public half with the authority (POST /v1/execution/provider-keys: kid, issuer, algorithm EdDSA, the OKP JWK), and the private half never leaves the provider. Revocation is a timestamp at the authority, never a deletion, so a receipt recorded under a retired key stays explicable. Rotation is a new kid.

Receipt. A compact JWS whose protected header is exactly alg EdDSA, kid the registered key id, typ decionis-effect-receipt+jwt, and whose claims are:

The claims the receipt binds are the attestation's, which is the point: the provider copies sub, decision_id, dossier_id, claim_token_digest and jti from the attestation it verified at step 6 and cannot have obtained them any other way, since the claim token itself never reaches it. claim_token_digest is what the authority compares with the claim token the executor finalizes with, so a receipt answers one claim of one grant and no other.

Canonical form. The header and the claims MUST be serialised in RFC 8785 canonical form before base64url encoding, so that every implementation signs the same bytes for the same receipt and the vectors can hold them to it. The signature is Ed25519 over the ASCII bytes of the first part, a dot, and the second part.

Transport. The response header x-agent-safe-effect-receipt, on every response to a request the provider accepted at step 8: the 2xx of an effect and the 4xx of the provider's own refusal alike. A signed refusal is evidence too. A response to a request refused at steps 0 to 8 carries no receipt: nothing was claimed of the provider.

What the executor does. @decionis/agentsafe verifies nothing in the receipt. It forwards the header's value verbatim as effect_receipt in finalize-token, whatever the attempt's outcome, when the value has the shape of a compact JWS and is at most 20000 characters; otherwise it drops it, since the authority refuses a malformed body and the commit outcome would be lost with it. Its effect plane does read what the receipt states, the effect block's status and digest, and compares that statement with its own account: the outcome the provider answered with, the effect the grant authorised, and the effect the adapter observed. Agreement is recorded; a receipt that names no digest is recorded as silent; a receipt whose status contradicts the outcome, or whose digest differs from the authorised effect or from the observation, is a mismatch the executor reports as EFFECT_MISMATCH, confirms nothing from, and treats as the same exception as an observation that did not match. A statement is not a verification: the authority's verdict on the signature is the one that counts, and the executor's comparison is what lets two witnesses' disagreement be seen at all.

What the authority does. It verifies the signature under the key the organisation registered for kid, requires iss to be the issuer registered with that key and aud to be itself, and checks that the receipt describes the finalization in hand: sub is the grant's jti, decision_id and dossier_id are the grant's, claim_token_digest is the digest of the claim token being finalized, and intent_hash, when present, is the one the grant bound. It records the receipt in the commit evidence as presented, verified or not, with one of six verification codes (EFFECT_RECEIPT_VERIFIED, _MALFORMED, _KEY_UNKNOWN, _SIGNATURE_INVALID, _BINDING_MISMATCH, _KEYS_UNAVAILABLE), and reports the verdict in the finalize response. When the grant carried expected_effect_digest and the verified receipt carries effect.digest, the receipt is read as Protocol 1.1 SIGNED_RECEIPT effect evidence with the provider key as observer, CONFIRMED only when the digests agree, the status is EFFECTED and the outcome is COMMITTED. A receipt is never a reason to refuse a finalization: what it changes is the evidence, not the commit.

What a receipt is not. A receipt authorises nothing and consumes nothing. A receipt for a grant the authority never claimed is recorded as a binding mismatch, and a receipt cannot be presented in place of an attestation. The executor's effect plane keeps reconciling its own observation; the receipt is the provider's statement beside it, compared with it, not a replacement for it.

8. Test vectors and claiming conformance

conformance/provider holds one JSON file per case. Each is self-contained: the provider's settings (whether it effects, its clock window, the time to verify at, the issuer it trusts), the executor keys it knows, the authority JWKS, and a sequence of requests, each with the outcome the procedure MUST reach. Every vector is generated by the executor's own signer and an independent signer for the attestation, and is run, in this repository, by the reference verifier in @decionis/agentsafe (verifyProviderRequest), by the Go implementation in verifiers/envoy, by the Java implementation in verifiers/spring, by the Rust implementation in verifiers/rust, and by the .NET implementation in verifiers/dotnet, five implementations that must agree. The receipt vectors in conformance/provider/receipts pin the other half: for each, the claims, the canonical header.payload every implementation MUST produce before signing, and a token signed by a key made for that generation whose public half the vector carries. An implementation of VP-3 passes them by producing that exact signing input and a signature its own key verifies; each of the five does.

To claim conformance, an implementation states the profile identifier and version, the level, and that every vector at that level passes with the outcomes the vectors name. It SHOULD state the tier (section 1) at which it is deployed, since the vectors cannot.

9. Deployment notes

• Executor keys. The provider issues, or records, the executor's Ed25519 public key under a keyid of its choosing; the executor names it with DOWNSTREAM_SIGNING_KEY_ID. Rotation is a new keyid; the old one is withdrawn once no dispatch can still carry it.
• Authority keys. Fetch the JWKS over HTTPS from the authority's own API origin, never from a location the request names. Cache it; on an unknown kid, refresh at most once per bounded interval before refusing. The authority rotates with overlap, so a verifier keeps the previous key for the overlap.
• Clock. Keep the provider's clock disciplined. exp is authoritative and short, the length of the lease the authority named in claim_lease_expires_at; the created window is defence in depth.
• Replay store. Keyed by grant id, expiring at exp, shared by every instance that can effect. Since a lease is tens of seconds, the store is small.
• Body. Verification needs the whole body: a hop that streams bodies through cannot verify, and MUST buffer up to a bound it sets and refuse beyond it. In Envoy, ext_authz needs with_request_body with allow_partial_message: false; the reference in verifiers/envoy answers the check with the refusal status and body above, which Envoy returns to the executor. In Kong, the plugin in verifiers/kong reads the body itself and runs the same Go verifier.
• Paths. Verify with the path as received, before any rewrite the hop applies.
• Receipt keys. Keep the receipt key with the same care as the credential the system of record accepts: a receipt is the provider's signature. Register the public half with the authority before the first receipt is signed, since a receipt under an unregistered kid is recorded as EFFECT_RECEIPT_KEY_UNKNOWN and confirms nothing. An authorization hop that runs the procedure in front of the system of record answers before the effect, so its access phase cannot sign a receipt; the receipt is the effecting layer's, or the hop's response phase signs one from what the system of record reports about the effect in its answer, as the Kong plugin in verifiers/kong does with receipt_key_file. Envoy's ext_authz has no response phase and signs none.

10. Security considerations

• The query is not covered. An effecting endpoint MUST NOT let a query parameter change what is effected, or MUST refuse an effecting request that carries one.
• A shared secret can be forged by the provider. hmac-sha256 makes VP-1 a statement the provider could have made itself; it is acceptable within one trust domain, and the attestation at VP-2 remains the authority's either way. For a system of record, prefer ed25519.
• The attestation is public. It is verifiable by anyone and a bearer for nothing: it carries no claim token, the executor's signature binds it to one request, and the lease bounds it in time. What it reveals is identifiers and digests, not parameters.
• Replay. A store that is per instance lets a second instance effect the same grant; the store's visibility, not its durability beyond the lease, is the requirement.
• Two digests, on purpose. The content digest binds the bytes; the attestation's digest binds the canonical parameters. A body with the same parameters in another key order or with other whitespace passes step 7 and fails step 1 unless the executor signed exactly those bytes, which is the intended division: the executor vouches for the bytes, the authority for the parameters.
• Refusals are informative. The reason code is for the executor's record; the response carries nothing else from the request.
• A receipt is public too. It is verifiable by anyone who holds the registered public key and a bearer for nothing: it names identifiers and digests, never parameters or the claim token. What it commits the provider to is what it says it did.

11. Status, versioning and citation

The profile identifier agent-safe.verifying-provider/1 changes only on an incompatible change to the procedure or the vectors. The version in this document's first line changes with the text. Released versions of this repository, this page included, are archived under the Zenodo concept DOI 10.5281/zenodo.22312955; cite the version DOI of the release that carries the text you implemented (release metadata). The pages on the same procedure from the executor's side are execution binding, claim and finalize, evidence, and bypass resistance.