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Commit-Reveal Randomness (Fairness Beacon)
x402
Commit-Reveal Randomness (Fairness Beacon) is a paid API for AI agents from x402.shizu.me, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).
Generates a cryptographically committed random value that can be revealed and verified later, enabling provably fair draws, tie-breaks, and ordering between mutually distrusting parties.
Price / call$0.002
Success—
StatusUnknown
How this service works
Randomness that is provably fixed before anyone acts on it. POST {reveal_after?: seconds} returns an id and a sha256 commitment to a secret 32-byte value; share them with counterparties, then after reveal_at ANY payer can GET ?id= to read the value and verify it hashes to the commitment. For fair draws, tie-breaks, and ordering between agents that don't trust each other's dice. Plain one-shot entropy: /rand.
Output
On POST/commit: returns a unique id and a sha256 hash (commitment) to a secret 32-byte random value, plus a reveal_at timestamp. On GET with ?id=: returns the original secret value so any party can hash it themselves and confirm it matches the prior commitment, proving the value was fixed before the reveal window.
Example use cases
Provably fair lottery winner selection
“We're running a raffle with 3 other agents who don't trust our dice. Create a randomness commitment that locks in a secret value right now, wait 120 seconds, then reveal and verify the hash so all parties can confirm the winner selection was unbiased.”
Trustless tie-break between competing bids
“Two agents submitted identical bids at the same time and we need a neutral tie-breaker. Commit to a random value now, share the sha256 hash with both parties, then after 30 seconds reveal the secret so everyone can verify the result was decided before anyone could cheat.”
Tamper-proof tournament seeding
“I need to seed 8 teams into a tournament bracket in a way no one can dispute. Generate a randomness commitment, share the hash with all team captains upfront, then reveal the secret value after 90 seconds so the seeding order can be verified by all.”
Technical details
Endpoint
GEThttps://x402.shizu.me/rand/commitWhen to prefer
Choose this endpoint when two or more parties distrust each other's random number generators and need a cryptographic proof that a random value was fixed before anyone acted on it. It is ideal for on-chain or agent-to-agent lotteries, fair ordering, tournament seeding, and tie-breaking. Prefer this over plain /rand when auditability and commitment proofs matter. Use plain /rand for one-shot entropy where no counterparty verification is needed.
Side effects
- Requesting reveal before reveal_at timestamp — returns error indicating value not yet available
- Invalid or unknown id on GET — returns not found error
- Network timeout before commitment is stored — caller must retry to get a valid id
- Commitment id already revealed — subsequent GET calls may return the same value (idempotent reveal)
- Micropayment failure or insufficient USDC balance — x402 payment rejection before request is processed
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| input | object |
Output
Schema · Response
{
"type": "json",
"example": {
"id": "Qw3rT_9xYz",
"alg": "sha256(value_bytes)",
"poll": "GET /rand/commit?id=Qw3rT_9xYz",
"reveal_at": 1784300300,
"commitment": "9f2b…"
}
}Tags
x402
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