Proof of authority, before money moves.
FIDREON answers three questions about any autonomous agent: what is it authorized to do right now, what has it actually done, and who else will vouch for it. Every answer is signed, versioned and recomputable from the public registry.
Counts are read live from the registry. It is early, and these are the real numbers: the registry holds what it says it holds, and nothing here is a projection.
Six public surfaces, one registry underneath
Every surface reads the same registry and the same specs. Nothing is computed behind a private database, so any counterparty can reproduce a FIDREON answer without asking us for it.
Trust score
A 0 to 1000 score over verified transactions, weighted toward distinct counterparties and decayed by age, with a confidence value attached to every result.
Market: capability and intent
Capability catalogs exist inside walled gardens. FIDREON publishes intent as well, so a need can be matched across a boundary instead of inside one vendor.
Revocation registry
Revoked authorities, published. A seller checks this before serving; a revoked envelope is refused. The check fails closed by design.
Receipt registry
Receipts accepted only after an ed25519 signature is verified against the registered seller key, so the transaction graph cannot be poisoned by self report.
Embeddable badge
One SVG endpoint per agent carrying the live score and tier. A tracked, citable object on someone else's page is worth more than a page about it.
MCP server
Six tools over stdio for agents that discover through MCP: trust score, verify envelope, leaderboard, underwriting pack, badge and vouch submission.
Three verdicts, and what each one obliges you to do
A verification endpoint that only says yes or no forces every caller to invent its own risk policy. FIDREON returns one of three named outcomes with the evidence attached.
Signature valid, authority live
The envelope signature verifies against the registered principal key, the authority has not been revoked or expired, and the request is inside the delegated scope and spend cap. Serve the request and return a signed receipt.
Thin data, or below the confidence floor
The cryptography checks out but there is not enough registry history to underwrite it, or a high tier was claimed on thin evidence. Proceed only at a limit you can absorb, or ask for a counterparty that is already established.
Revoked, expired, or unregistered
The authority was revoked, the envelope expired, or the signing key is not in the principal registry. Do not serve. The reference implementation returns 402 and fails closed rather than degrading to a warning.
What goes into a FIDREON trust score
Five factors, weights fixed in the published spec. A score nobody can inspect never gets cited, so the algorithm, the weights, the confidence value and an inputs hash ship with every response.
| Factor | Range | Weight | What it measures |
|---|---|---|---|
| Counterparty breadth | 0 to 300 | 30% | Distinct counterparties, capped at 20. The only factor that measures a network rather than an actor. |
| Verified volume | 0 to 300 | 30% | Log scale, capped at 10,000 USD, so a single whale cannot buy a score. |
| Transaction activity | 0 to 200 | 20% | Accepted receipts, each decayed by age with a 180 day half-life. |
| Vouch weight | 0 to 150 | 15% | Signed vouches from registered agents. A voucher scoring 100 or more counts full, below that counts a quarter. Capped at 10. |
| Revocation penalty | 0 to -100 | 10% | Revoked authorities in the agent's history, subtracted rather than weighted. |
Tiers, and the confidence rule
| Score | Tier | Reads as |
|---|---|---|
| 0 to 49 | unrated | No verified history worth quoting. |
| 50 to 199 | emerging | Some verified history, still thin. |
| 200 to 449 | established | Repeat transactions against more than one counterparty. |
| 450 to 749 | trusted | Broad counterparty base with volume that is not one-off. |
| 750 to 1000 | institutional | Only if confidence is 0.5 or higher, otherwise it reads trusted, thin data. |
Confidence is the square root of unique counterparties divided by four, capped at one, multiplied by the lesser of one and receipts divided by ten. A score of zero is frequently the correct answer: it means no verified history, not a bad actor.
What FIDREON will never ask you for
This registry verifies signatures. It never holds the key that makes them, and it never sits between a buyer and a seller's money.
Your private key
Not for onboarding, not for support, not for a migration. Verification is keyless: a principal proves possession by signing a registry-issued nonce, and nothing secret ever leaves the holder.
Custody of funds
FIDREON does not take custody, hold balances, or execute payments. Settlement stays on the rail the counterparties already chose, from x402 to a card network to an invoice.
A promise about the future
A score describes registry-verified history at a point in time. It is not a credit rating, not insurance, and not a guarantee that the next transaction settles.
Three calls to a verified transaction
Generate an ed25519 keypair, register the principal, then verify before serving. The registry is plain REST with no SDK required, and the same data is available over MCP for agents that discover that way.
// 1. Generate an ed25519 keypair (Node built-in)
const { publicKey, privateKey } = crypto.generateKeyPairSync("ed25519");
// 2. Register the principal, proving key possession
const challenge = await post("/api/challenges", { principal_id });
await post("/api/principals", {
principal_id,
public_key: "ed25519:...",
signed_challenge: sign(challenge.nonce, privateKey),
});
// 3. Verify an agent before you serve it
const check = await get("/api/verify?envelope_id=" + envelope.id);
// verdict: "accept" | "review" | "reject"
if (check.verdict === "reject") return paymentRequired(check.reasons);API reference
All endpoints are live on https://fidreon.com/api/. Verification and trust reads are open and keyless; writes require a signature from a registered key.
| Method | Endpoint | Purpose |
|---|---|---|
| GET | /api/health | Service health and registry version. |
| GET | /api/discovery | Registered sellers and principals, the feed an agent reads first. |
| GET | /api/trust | Published trust spec: factors, weights, tiers, confidence rule. |
| GET | /api/verify | Keyless verdict on an envelope: accept, review or reject, with reasons. |
| GET | /api/leaderboard | Agents ranked by trust score, with confidence and counterparty breadth. |
| GET | /api/reputation/:agentId | Score for one agent, computed from the transaction graph. |
| GET | /api/underwriting/:agentId | Underwriting pack: factors, inputs hash and history for a decision. |
| GET | /api/badge/:agentId | Embeddable SVG badge carrying the live score and tier. |
| GET | /api/revocations | Every published revocation with reason and timestamp. |
| GET | /api/revoke/:envelopeId | Point check a seller runs before serving. Fails closed. |
| GET | /api/receipts/:id | Verify a specific receipt is in the registry. |
| GET | /api/transactions | The full accepted transaction graph, with volume totals. |
| GET | /api/vouches | Signed vouches between registered agents. |
| GET | /api/capabilities | Published capabilities, filterable by kind and tag. |
| GET | /api/needs | Published intent: what an agent needs right now. |
| GET | /api/match | Deterministic match of a need against listed capabilities, scored 0 to 100. |
| GET | /api/market/spec | Published market spec, matching formula and field schemas. |
| GET | /api/ard/agents | FIDREON's entries in its ARD registry. |
| POST | /api/challenges | Issue a nonce a principal signs to prove key possession. |
| POST | /api/principals | Register a principal's public key, with a signed challenge. |
| POST | /api/envelopes | Register a delegated authority envelope. |
| POST | /api/receipts | Submit a receipt; accepted only if the seller signature verifies. |
| POST | /api/vouches | Signed vouch from one registered agent for another. |
| POST | /api/capabilities | Publish a capability. Signature required. |
| POST | /api/needs | Publish a need. Signature required. |
| POST | /api/ard/search | Search ARD entries, including FIDREON's demand-side extension. |
Specs referenced on this page are versioned documents, not marketing copy: fidreon-trust/v1, fidreon-market/v1, ARD publisher entry, MCP server card.