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Home/Servers/Fairseal

Fairseal

by io.fairseal

Verifiable entropy, provably-fair games, and receipt verification for AI agents (FairSeal API).

Power your agent

Add this server

The publisher's own command. Not a PlugMCP endpoint.

Local command
npx -y @fairseal/[email protected]
Credentials from the publisher
  • FAIRSEAL_API_KEY β€” API key for gated tools (fairseal_entropy, fairseal_stats, fairseal_rng_generate, fairseal_notarize_decision, fairseal_anchor_submit). Key prefix: fsn_. Without a key these tools return 401; free tools (game reads, notarize_status, anchor_status) work without any key. x402 micropayment ($0.02 USDC on Base) is an alternative to the key for notarize/anchor.
  • FAIRSEAL_API_URL β€” Upstream API base URL (default https://api.fairseal.io).
  • FAIRSEAL_NOTARY_API_KEY β€” Key override for the notary service only (POST /v1/notarize). Falls back to FAIRSEAL_API_KEY if not set. Key prefix: fsn_.
  • FAIRSEAL_ANCHOR_API_KEY β€” Key override for Anchor API v2 only (POST /v2/anchor). Falls back to FAIRSEAL_API_KEY if not set. Key prefix: anck_.
Provider
Claude Code
FAIRSEAL_API_KEY=<secret> FAIRSEAL_API_URL=<value> FAIRSEAL_NOTARY_API_KEY=<secret> FAIRSEAL_ANCHOR_API_KEY=<secret> claude mcp add io.fairseal-mcp-server -- npx -y @fairseal/[email protected]

Run in a terminal.

Claude Desktop
{
  "mcpServers": {
    "io.fairseal-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@fairseal/[email protected]"
      ],
      "env": {
        "FAIRSEAL_API_KEY": "<secret>",
        "FAIRSEAL_API_URL": "<value>",
        "FAIRSEAL_NOTARY_API_KEY": "<secret>",
        "FAIRSEAL_ANCHOR_API_KEY": "<secret>"
      }
    }
  }
}

claude_desktop_config.json

Step-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

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Verifiable entropy, provably-fair games, and receipt verification for AI agents (FairSeal API).

Fairseal 🦭

Provably fair selections for games, loot boxes, and any randomized allocation.

Fairseal creates verifiable receipts (CSRs) proving that a selection was committed before the outcome was knowable. Every loot drop, gacha pull, and randomized selection β€” independently verifiable, trustlessly.

Try It Now

npx @fairseal/commit

One command. A verifiable gacha pull in your terminal. No setup.

Quick Start

npm install @fairseal/commit

import { createCommitment, resolveCommitment, createReceipt, verifyReceipt } from '@fairseal/commit';

// 1. Lock your loot table BEFORE the outcome is knowable
const commitment = createCommitment({
  rule: JSON.stringify(LOOT_TABLE),
  inputs: [playerId, pullNumber.toString()],
  revealAfter: 10,
});

// 2. Resolve with verifiable entropy from drand
const resolution = await resolveCommitment(commitment);

// 3. Your algorithm + verifiable entropy = provably fair drop
const drop = yourWeightedPull(LOOT_TABLE, resolution.beaconRandomness);

// 4. Package as a receipt anyone can verify
const receipt = createReceipt(commitment, resolution);
const proof = await verifyReceipt(receipt); // βœ… PARTIAL

How It Works

  1. Commit β€” Lock your drop table + player ID into a hash before the randomness exists
  2. Entropy β€” Wait for a public drand beacon round (Cloudflare + Protocol Labs)
  3. Resolve β€” Derive the selection from beacon entropy + your committed rule
  4. Verify β€” Anyone can re-run every step. drand beacon signatures are BLS12-381-verified; FairSeal receipt signatures use EIP-191 (secp256k1) / Ed25519 β€” receipts are never BLS-signed. No trust required.

Performance

OperationTime
Commitment creation0.006ms (170,000+/sec)
Beacon fetch~200ms
drand beacon verification (BLS12-381)~150ms
Receipt size0.9 KB

Client-side. No server. No account. No fees for PARTIAL verification.

Packages

PackageDescription
@fairseal/gameGame API for RGS studios. Slots, gacha, loot boxes. (v0.1 ALPHA)
@fairseal/commitCommitted selection receipts. Core library.
@fairseal/coreCryptographic primitives, signing, Merkle trees.
@fairseal/verifyIndependent receipt verification.
@fairseal/mcp-serverMCP server for AI agents. Verifiable entropy, provably-fair games, cryptographic receipt verification via Model Context Protocol.

Use Cases

ScenarioHow
Gacha / loot boxEvery pull has a receipt. Players verify drops match published rates.
Boss loot dropsDrop table committed per encounter. No ninja-nerfing.
MatchmakingPairing algorithm committed. Players verify no favoritism.
Tournament bracketsSeeding provably random, not rigged.
NFT mint orderQueue provably fair β€” no insider front-running.
Slot machinesSeed Commitment Model β€” verifiable spins, no nonce chain.

Result Notarization vs. Activity Receipts

Most "agent receipts" today are activity receipts: the platform logs what an agent did, and you trust whoever wrote the log. Fairseal receipts are result notarization β€” a different trust model:

Activity receipts (platform logs)Fairseal result notarization
Who do you trust?The operator writing the logNo one β€” receipts verify offline
What is proven?That an action was recordedThat a result was committed before the outcome was knowable
Time proofServer timestamp (operator-controlled)External anchor on Base (independently checkable)
Tamper evidenceDepends on log integrityHash-anchored; any modification breaks verification

Related standards: payment-authorization protocols like Google/Mastercard AP2 (mandates), Visa TAP, and OpenAI/Stripe ACP prove that an agent may act and who it is. Fairseal proves what happened β€” that a result was committed and hasn't been altered since. Fairseal settles micropayments over Coinbase's x402 and does not implement AP2/TAP/ACP; the layers are complementary.

Links

  • 🌐 fairseal.io β€” Landing page
  • πŸ“¦ npm @fairseal β€” All packages
  • πŸ” verify.fairseal.io β€” Receipt verifier
  • πŸ“– @fairseal/commit README β€” Full documentation

License

MIT β€” Fairseal

How do I install Fairseal?
Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.
Does Fairseal need an API key?
The publisher lists these environment variables: FAIRSEAL_API_KEY, FAIRSEAL_API_URL, FAIRSEAL_NOTARY_API_KEY, FAIRSEAL_ANCHOR_API_KEY.
What transport does Fairseal use?
Fairseal runs locally over stdio.
When was Fairseal last checked?
Last checked 2026-10-16. Verifiable entropy, provably-fair games, and receipt verification for AI agents (FairSeal API).

No tool list yet. Remote servers get one after the first health check.

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