Signed, offline-verifiable settled outcomes

01The problem

Agents and on-chain systems increasingly act on settled outcomes — to settle a bet or parlay, resolve a dispute, score a track record, feed a backtest, or keep an audit trail. The truth usually exists somewhere: Polymarket and Kalshi resolve their markets, a game finishes with a final score. But consuming that truth provably means running a node, trusting an oracle or an RPC/indexer, or scraping a scoreboard yourself — and an outcome passed around in a plain HTTP body or a tool-call is not portable proof: it can be edited, replayed, or misattributed.

There's no drop-in, offline-verifiable "this market resolved YES / this game ended 112–104, final — here's a signature anyone can check" record for the x402 / agent world. That portable record is what Predge Attest is — not a stronger truth anchor than the chain or an oracle, a far more portable one.

02What it is

Every attestation — across all four verticals — returns the same self-contained signed envelope:

{
  "payload":    { /* the settled facts for this outcome */ },
  "canonical":  "…",           // payload as JSON, keys sorted, no whitespace
  "signature":  "…",           // ed25519 over `canonical` (hex, 64 bytes)
  "public_key": "13fa3d18…52d9" // raw 32-byte ed25519 point
}

• Verify offline, no trust in Predge at call time. Re-canonicalise payload, check signature against the key published at data.predge.io/.well-known/predge-attest.json. If it verifies, the outcome is authentic and untampered — provable to a third party, a contract, or an auditor, years later, with no dependency on Predge or a chain connection.
• Settled, not modeled. Every payload is the final result from the outcome's own source of record — a resolved market, a finished game — never an estimate or a projection.
• One key, one verify recipe. The same ed25519 key 13fa3d18…52d9 signs all four verticals; write the verifier once and it checks every attestation Predge issues.

03The four attestations

One primitive, four settled-outcome sources. Each is $0.02 per call and returns the same signed envelope.

04Why it's defensible

• Portability is the wedge. The win is offline verification in one crypto.verify(), with nothing to run — no node, no oracle, no scraper, no RPC. Drop the signed record straight into an agent tool-call, a paid API response, a dispute file, a leaderboard, or a Web2 audit trail, and anyone can re-verify it forever.
• Signed settled outcomes across prediction markets, sports and Kalshi. Not a single feed but a signing layer that spans four settled-outcome classes under one key and one verify recipe — a breadth a single-vertical source can't match.
• Not a new trust anchor. If you already run an oracle or a node for on-chain settlement, keep it — this is for the many agents and tools that just need a verifiable result they didn't have to source or trust themselves. We don't claim to be more trustworthy than the chain or an oracle; we claim to be more portable.
• Published, stable key. 13fa3d18…52d9 lives on the canonical origin — verification never needs to hit Predge again.
• Proven end-to-end. Real paid calls have been independently verified (crypto.verify = true) and a tampered payload is correctly rejected. See it yourself on the free 2-minute proof page.

05Who it's for

06How to consume it & pricing

• Pay-per-call over x402 — $0.02 per attestation, USDC on Base or Solana mainnet (gasless via facilitator). No API keys, no accounts, no signup — a wallet just pays. Errors, unfinished games, and unknown IDs are never charged.
• As MCP tools — predge_attest, predge_sports_attest, predge_kalshi_attest, and predge_wallet_attest in @predge/whale-data-mcp (official MCP Registry), for MCP-native agents and hosts.
• Raw HTTP — GET the endpoint, 402 → PAYMENT-SIGNATURE → 200 + the signed envelope. Every 402 advertises both Base and Solana accepts; pick the network your wallet holds USDC on.
• Volume / integration tiers negotiated per partner — dedicated pricing, a test wallet, or a custom envelope/discovery format turned around same-day.

Verify every claim (2 min, free) → Full docs