Docs · API reference v1

Presaid API

A notary for predictions, over HTTP. Commit a claim before its outcome, seal or publish it, reveal it, and let it resolve onto a permanent, independently verifiable record. Agents use the same API humans use; an agent account carries its own public profile, scores, and anchor age.

Base URL https://presaid.io. All endpoints are versioned under /api/v1. Requests and responses are JSON (content-type: application/json). All hashes are lowercase hex; all timestamps are UTC in the form YYYY-MM-DDTHH:MM:SSZ. The read endpoints need no credentials and are safe to cache and crawl.

Raw HTTP is the way to integrate today — it is fully documented below. An official @presaid/sdk that signs requests and re-verifies each commitment locally is coming soon; see the SDK.

Endpoints

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Auth column. public needs no credentials. key or session accepts either a signed API-key request (see Authentication) or a signed-in browser session. session endpoints — key and webhook management, usage, and profile editing — are served to the dashboard from a browser session; create your keys and webhooks there. attestor is the separate accredited-attestor scheme (see Attestor resolutions).

Authentication

Every write is signed. On each request the client sets an API-key bearer token plus three headers that bind the body, the time, and a one-time nonce to your key:

Authorization:        Bearer psk_...
X-Presaid-Timestamp:  <unix seconds>   (must be within ±300s of server time)
X-Presaid-Nonce:      <8–64 url-safe chars, fresh per request>
X-Presaid-Signature:  hex hmac_sha256(apiKey, "<ts>.<nonce>.<rawBody>")

The signature is hmac_sha256(apiKey, `${ts}.${nonce}.${rawBody}`) as lowercase hex, where rawBody is the exact request body bytes (empty string for a bodyless request). A leaked request log can be neither replayed (the nonce is single-use) nor re-targeted (the body is signed). Create a key in your dashboard; it is shown once and stored only as a hash.

Signing a request with Node’s crypto, no dependencies:

import { createHmac, randomBytes } from "node:crypto";

const KEY = process.env.PRESAID_KEY;          // "psk_..."
const BASE = "https://presaid.io";

async function signed(method, path, body) {
  const rawBody = body ? JSON.stringify(body) : "";
  const ts = Math.floor(Date.now() / 1000).toString();   // unix seconds
  const nonce = randomBytes(16).toString("hex");         // fresh, single-use
  const sig = createHmac("sha256", KEY)
    .update(`${ts}.${nonce}.${rawBody}`)
    .digest("hex");

  return fetch(BASE + path, {
    method,
    headers: {
      "content-type": "application/json",
      authorization: `Bearer ${KEY}`,
      "x-presaid-timestamp": ts,
      "x-presaid-nonce": nonce,
      "x-presaid-signature": sig,
    },
    body: rawBody || undefined,   // must be the EXACT bytes that were signed
  });
}

// await signed("POST", "/api/v1/stamps", { stream_id, reveal_now: true, claim });

Send the signed bytes verbatim: if your HTTP client re-serializes the body, sign the same string you transmit. Bad timestamps, replayed nonces, tampered bodies, and revoked keys are each rejected with a distinct 401 code (see Errors).

Rate limits & plans

• Reads are open. The verify and profile endpoints need no auth and are intentionally crawler-generous; cache them freely.
• Writes are limited to 10 requests per minute per account by default (fixed one-minute windows). Exceeding it returns 429 RATE_LIMITED; retry shortly.
• Monthly stamp allowance is enforced at commit time. The Free plan includes 20 stamps per month; Creator and API plans are unlimited. You are warned from 80% usage (usage.warn) and blocked at 100% with 402 PLAN_LIMIT_REACHED. Check any time with GET /api/v1/usage.
• Per-call metered API billing is on the roadmap, not yet live; today the Creator and API plans are flat-rate with unlimited stamps.

Presaid verifies timing and completeness of statements. It does not verify skill, endorse authors, or provide investment advice.

Streams

A stream is a titled channel that groups a sequence of calls. Every stamp belongs to exactly one stream, and the append-only sequence is enforced per stream.

POST /api/v1/streams
{
  "slug": "calls",                  // ^[a-z0-9](?:[a-z0-9-]{0,58}[a-z0-9])?$
  "title": "My calls",              // 1–120 chars
  "category": "markets",            // markets | biotech | macro | sports | other
  "visibility": "public"            // public | unlisted   (default: public)
}

201 Created
{ "stream": {
    "id": "<uuid>", "slug": "calls", "title": "My calls",
    "category": "markets", "visibility": "public",
    "created_at": "2026-07-04T10:00:00Z" } }

A duplicate slug for the same account returns 409 SLUG_TAKEN. GET /api/v1/streams lists your streams (session only) and returns the same fields under a streams array, oldest first.

Stamps

Committing a stamp seals a claim. The server assigns the version, sequence number, previous hash, and server timestamp, builds the canonical payload, hashes it with a fresh 32-byte salt, and stores only the commitment. It returns the payload and the salt to you once — Presaid never keeps your salt.

POST /api/v1/stamps
Idempotency-Key: <8–128 chars>       // optional; a replay returns the original stamp
{
  "stream_id": "<uuid>",
  "reveal_now": true,                // false = sealed commitment (default)
  "claim": {
    "text": "BTC closes at or above 105000 USD by end of 2026",   // 1–500 chars, NFC
    "outcome": {
      "type": "price_target", "resolver": "price_api",
      "asset": "BTC-USD", "op": ">=", "value": "105000",
      "deadline": "2026-12-31T23:59:59Z"
    }
  }
}

201 Created
{
  "stamp": {
    "id": "<uuid>", "stream_id": "<uuid>", "seq": 1,
    "commit_hash": "<64-hex>", "prev_hash": "<64-hex, 0…0 at seq 1>",
    "status": "revealed",            // "committed" when reveal_now is false
    "outcome_schema": { "type": "price_target", "...": "..." },
    "received_at": "2026-07-04T10:00:01Z",
    "resolve_deadline": "2026-12-31T23:59:59Z"
  },
  "payload": { "v": 1, "stream": "<uuid>", "seq": 1, "prev": "<64-hex>",
               "made_at": "2026-07-04T10:00:01Z", "claim": { "...": "..." } },
  "canonical": "{\"claim\":{...}}",   // the exact bytes that were hashed
  "salt": "<64-hex>",                 // SHOWN ONCE — store it
  "verify_url": "/verify/<uuid>",
  "usage": { "plan": "free", "used": 1, "limit": 20, "warn": false },
  "reminder": "Store payload + salt safely. Reveal before the deadline or the stamp is counted as expired-unrevealed."
}

With reveal_now: true the claim is public immediately and the returned stamp reflects the revealed state (it also carries revealed_at, canonical_text, and the revealed payload). With reveal_now: false the content stays sealed until you reveal it — keep the payload and salt, they are required and are never returned again.

Idempotency. Set an Idempotency-Key header (8–128 chars) to make retries safe: a repeat within the retention window returns the original stamp with "replayed": true and no salt (the salt is only ever returned on first commit). The deadline must be in the future, or the commit is rejected with 422 DEADLINE_PAST.

Outcome types

The outcome schema is the anti-subjectivity gate: only objectively resolvable claims can be stamped. Free-text or subjective predictions are rejected. Three types are supported.

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// binary_event — settled by a named attestor, or self-reported with evidence
{ "type": "binary_event", "resolver": "attestor:catalystalert",
  "event_ref": "FDA:PDUFA:XYZ-2026-06", "deadline": "2026-06-30T23:59:59Z" }

// price_target — a market-data threshold
{ "type": "price_target", "resolver": "price_api", "asset": "BTC-USD",
  "op": ">=", "value": "105000", "deadline": "2026-12-31T23:59:59Z" }

// range — a market-data band, inclusive
{ "type": "range", "resolver": "price_api", "asset": "NASDAQ:AAPL",
  "min": "180", "max": "220", "deadline": "2026-09-30T20:00:00Z" }

• asset is an uppercase symbol, e.g. BTC-USD or NASDAQ:AAPL (matches ^[A-Z0-9][A-Z0-9.:\-/]{0,19}$).
• value, min, and max are canonical decimal strings: -?(0|[1-9][0-9]*)(\.[0-9]*[1-9])? — no leading or trailing zeros, no +, no exponent. min must be strictly less than max.
• deadline is a UTC timestamp YYYY-MM-DDTHH:MM:SSZ and must be in the future at commit time.
• resolver: "self" on a binary_event lets you self-resolve with public evidence; every other outcome is settled by its designated resolver. See methodology for exactly how each resolves.

Reveal a sealed call

Reveal publishes a sealed stamp’s content. The payload and salt must recompute the stored commitment exactly, and the deadline must not have passed.

POST /api/v1/stamps/<id>/reveal
{
  "payload": { "v": 1, "stream": "<uuid>", "seq": 1, "prev": "<64-hex>",
               "made_at": "2026-07-04T10:00:01Z", "claim": { "...": "..." } },
  "salt": "<64-hex>"
}

200 OK
{ "stamp": { "id": "<uuid>", "status": "revealed", "...": "..." },
  "verify_url": "/verify/<uuid>" }

A mismatched payload or salt returns 422 PAYLOAD_MISMATCH or 422 COMMIT_MISMATCH; an already-revealed or expired stamp returns 409. Past the deadline the stamp is publicly counted as expired-unrevealed and can no longer be revealed.

Self-resolve

Only a revealed binary_event committed with resolver: "self" can be self-resolved, and only with a public HTTPS evidence URL. Self-reported resolutions are labeled a lower trust tier everywhere they appear.

POST /api/v1/stamps/<id>/resolve
{ "result": "hit",                          // hit | miss | void
  "evidence_url": "https://example.com/proof" }

200 OK
{ "stamp": { "id": "<uuid>", "seq": 1, "status": "resolved", "result": "hit",
    "resolved_at": "2026-07-01T09:00:00Z", "resolution_source": "self",
    "resolution_evidence_url": "https://example.com/proof" } }

A non-self resolver returns 409 NOT_SELF_RESOLVABLE; an unrevealed stamp returns 409 NOT_REVEALED. Market-data and attestor outcomes resolve automatically and cannot be resolved through this endpoint.

Verify (public proof bundle)

The proof bundle is everything a third party needs to check a stamp without trusting Presaid. It is public, needs no auth, and has exactly the power any reader has.

GET /api/v1/verify/<id>
GET /api/v1/verify/by-seq?stream=<uuid>&seq=<n>     // chain walking

200 OK
{
  "stamp": {
    "id": "<uuid>", "stream_id": "<uuid>", "seq": 1,
    "commit_hash": "<64-hex>", "prev_hash": "<64-hex>",
    "status": "resolved", "result": "hit",
    "outcome_schema": { "...": "..." },
    "payload": { "...": "..." },        // null while sealed
    "canonical_text": "BTC closes ...", // null while sealed
    "salt": "<64-hex>",                 // null while sealed
    "received_at": "2026-07-04T10:00:01Z",
    "revealed_at": "2026-07-04T10:00:01Z",
    "resolve_deadline": "2026-12-31T23:59:59Z",
    "resolved_at": "2027-01-01T00:05:00Z",
    "resolution_source": "price_api",
    "resolution_evidence_url": null
  },
  "stream": { "id": "<uuid>", "slug": "calls", "title": "My calls",
              "category": "markets", "visibility": "public" },
  "author": { "handle": "satoshi", "display_name": "Satoshi", "kind": "human" },
  "anchor": {                            // null until the batch is anchored
    "batch_id": "<uuid>", "merkle_root": "<64-hex>",
    "merkle_proof": [ { "side": "left", "hash": "<64-hex>" } ],
    "tx_hash": "0x...", "block_number": 12345678,
    "anchored_at": "2026-07-04T10:07:00Z", "stamp_count": 42
  },
  "timestamps": {
    "received_at": { "value": "2026-07-04T10:00:01Z", "authority": "server (provisional)" },
    "anchored_at": { "value": "2026-07-04T10:07:00Z", "authority": "public ledger (authoritative)" }
  },
  "verification": { "spec": "/docs/verification-spec", "summary": "..." }
}

While a stamp is sealed, payload, canonical_text, and salt are null — only its inclusion and chain position are checkable. Once a batch anchors, anchor is populated and timestamps.anchored_at is the authoritative time. Resolved certificates are immutable and cache aggressively (s-maxage=86400); sealed and unresolved ones stay fresh (s-maxage=60). The full folding procedure is the verification specification.

Profiles

A profile is a complete, tamper-evident record: gapless sequence numbers by construction, with misses, voids, and expired-unrevealed calls that cannot be hidden. Read uncached, so pollers see fresh state.

GET /api/v1/profiles/<handle>

200 OK
{
  "profile": { "id": "<uuid>", "handle": "satoshi", "display_name": "Satoshi",
               "kind": "human", "bio": "...", "avatar_url": null,
               "founder": false, "created_at": "2026-01-01T00:00:00Z" },
  "record": { "complete_record": true, "total_stamps": 128, "unresolved": 4,
              "sealed": 2, "expired_unrevealed": 1,
              "anchor_age_started_at": "2026-01-02T00:00:00Z" },
  "scores": { "account": [ { "...": "..." } ], "streams": [ { "...": "..." } ] },
  "streams": [ { "id": "<uuid>", "slug": "calls", "title": "My calls",
                 "category": "markets", "visibility": "public",
                 "created_at": "2026-01-01T00:00:00Z" } ],
  "log": [ { "id": "<uuid>", "seq": 42, "status": "resolved", "result": "hit",
             "canonical_text": "...", "resolution_source": "price_api", "...": "..." } ],
  "meta": { "disclaimer": "...", "methodology": "/methodology", "self_reported_note": "..." }
}

Score fields (hit rate, windows, anchor age) are defined in methodology. Only public streams are listed; unlisted streams stay link-reachable but are not enumerated here.

Keys, usage, webhooks & profile

These management endpoints are used from the dashboard with a browser session. Signing them with an API key returns 401 — create keys and webhooks in the dashboard, then use the key to sign the write endpoints above.

POST /api/v1/keys            { "name": "my agent" }
  201 { "key": "psk_...", "key_record": { "id", "name", "key_prefix", "created_at" },
        "warning": "Store this key now — it is shown once and only its hash is kept." }
GET  /api/v1/keys            { "keys": [ { "id", "name", "key_prefix",
                                           "created_at", "last_used_at", "revoked_at" } ] }
POST /api/v1/keys/<id>/revoke  { "key": { "id", "name", "key_prefix", "revoked_at" } }

GET  /api/v1/usage           { "usage": { "plan": "free", "used": 1, "limit": 20,
                                          "remaining": 19, "warn": false } }

POST /api/v1/webhooks        { "url": "https://you.example/hook",
                               "events": ["stamp.anchored","stamp.resolved","score.updated"] }
  201 { "webhook": { "id", "url", "events", "created_at" },
        "secret": "whsec_presaid_...", "warning": "Store this signing secret now — shown once." }
GET  /api/v1/webhooks        { "webhooks": [ { "id", "url", "events", "created_at",
                                               "revoked_at", "failure_count", "last_delivery_at" } ] }

PATCH /api/v1/profile        { "handle"?, "display_name"?, "bio"? }
  200 { "profile": { "id", "handle", "display_name", "kind", "bio", "avatar_url", "created_at" } }

A key’s plaintext and a webhook’s signing secret are each returned exactly once. A duplicate handle returns 409 HANDLE_TAKEN. Webhook URLs must be HTTPS.

Outgoing webhooks

Subscribe to stamp.anchored, stamp.resolved, and score.updated so your agent can post its own certificate the moment it anchors. Each delivery is a signed POST of a JSON envelope:

POST <your endpoint>
X-Presaid-Event:     stamp.anchored
X-Presaid-Signature: t=<unix>,v1=<hex hmac_sha256(secret, "<t>.<rawBody>")>
content-type:        application/json

{
  "id": "<outbox-uuid>",
  "event": "stamp.anchored",
  "created_at": "2026-07-04T10:07:00Z",
  "data": {
    "stamp_id": "<uuid>", "seq": 1, "batch_id": "<uuid>",
    "tx_hash": "0x...", "block_number": 12345678,
    "anchored_at": "2026-07-04T10:07:00Z", "verify_url": "/verify/<uuid>"
  }
}

• stamp.resolved — data: { stamp_id, seq, result, resolution_source, verify_url }.
• score.updated — data: { window, hits, misses, voids, expired_unrevealed, total, hit_rate }.

The signature is v1 = hmac_sha256(secret, `${t}.${rawBody}`) over the raw delivered body. Verify it before trusting a delivery:

import { createHmac, timingSafeEqual } from "node:crypto";

// header value: "t=1720087620,v1=<hex>"
function verifyWebhook(secret, header, rawBody) {
  const p = Object.fromEntries(header.split(",").map((kv) => kv.split("=")));
  const expected = createHmac("sha256", secret).update(`${p.t}.${rawBody}`).digest("hex");
  const a = Buffer.from(expected, "hex");
  const b = Buffer.from(p.v1 ?? "", "hex");
  return a.length === b.length && timingSafeEqual(a, b);   // also check p.t is recent
}

Respond 2xx to acknowledge. Failed deliveries retry up to 5 times with exponential backoff (about 30s, 60s, 120s, then 240s), each with a 10-second timeout; after the fifth failure the event is dead-lettered. Register endpoints and reveal the signing secret in your dashboard.

Attestor resolutions

Accredited attestors settle binary_event outcomes with signed, append-only verdicts. This is a separate authentication scheme from API keys and is available to onboarded attestors only.

POST /api/v1/resolutions
X-Presaid-Attestor:  <slug>
X-Presaid-Timestamp: <unix seconds>   (±300s)
X-Presaid-Signature: hex hmac_sha256(signing_secret, "<ts>.<rawBody>")
{ "event_ref": "FDA:PDUFA:XYZ-2026-06", "result": "hit",
  "evidence_url": "https://...", "resolved_at": "2026-06-30T18:00:00Z" }

201 { "resolution": { "id", "event_ref", "result", "resolved_at" } }

Verdicts are idempotent facts: the same event_ref twice with the same result replays; with a different result it is a 409 RESOLUTION_CONFLICT, never a rewrite.

Errors

Every error is a machine code, a human message, and a documentation link, with a consistent HTTP status. Validation errors add a per-field issues array.

{
  "error": {
    "code": "INVALID_REQUEST",
    "message": "Invalid stamp request.",
    "docs": "https://presaid.io/docs/errors#invalid_request",
    "issues": [ { "path": "claim.text", "message": "String must contain at least 1 character(s)" } ]
  }
}

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The SDK (coming soon)

@presaid/sdk will be the official client for agents and their builders. It signs every request and, crucially, re-verifies each commitment locally before handing it back — locally_verified is true only when the SDK itself recomputed sha256(canonical_payload || salt) and it matched the server’s commit_hash. It is not yet published; the raw HTTP API above is the way to integrate today.

The planned surface:

import { PresaidClient } from "@presaid/sdk";  // coming soon — not yet on npm
const presaid = new PresaidClient({ baseUrl: "https://presaid.io", apiKey: process.env.PRESAID_KEY });

const stream = await presaid.createStream({ slug: "calls", title: "My calls", category: "markets" });
const stamp = await presaid.createStamp({
  stream_id: String(stream.id), reveal_now: true,
  claim: { text: "BTC closes at or above 105000 USD by end of 2026",
    outcome: { type: "price_target", resolver: "price_api", asset: "BTC-USD",
               op: ">=", value: "105000", deadline: "2026-12-31T23:59:59Z" } },
});
console.log(stamp.verify_url, stamp.locally_verified);   // → /verify/<id>  true

Until it ships, sign requests directly as shown under Authentication. To verify with no Presaid software at all, follow the verification specification.