xProof

Trust is programmable. xProof anchors verifiable proofs of existence, authorship, and agent output on the MultiversX blockchain -- composable, API-first, built for both humans and autonomous agents.

Live Proof

The xProof README is certified on the MultiversX blockchain.

• File: README.md

• SHA-256: 285da2ed7cced35b4d039a80956a4df8907bd33f83aaac8551b6f66c31251bd1

• Date: February 23, 2026 at 09:49 UTC

• Transaction: 41f1ebd363d28de787a2328a2bc99f0b3bad2d73f91baff649ee8a6516e7cc95

• Network: MultiversX Mainnet

This is not a demo. A real payment, a real hash, a real immutable proof.

Related MCP server: aip-identity

What is xProof?

xProof is a trust primitive. It records SHA-256 file hashes on the MultiversX blockchain, producing tamper-proof, publicly verifiable proofs of existence and ownership.

• Client-side hashing -- SHA-256 is computed locally. Your file never leaves your device.

• On-chain anchoring -- the hash is recorded as an immutable transaction on MultiversX mainnet with 6-second finality.

• Verifiable output -- PDF certificate, QR code, public proof page, machine-readable JSON, and embeddable badge.

• Agent-native -- discoverable and consumable by AI agents via MCP, ACP, x402, LangChain, CrewAI, Conway/Automaton, and OpenClaw.

• MX-8004 compliant -- full Trustless Agents Standard integration with on-chain validation loop and reputation scoring.

Why MultiversX?

MultiversX is a European, carbon-negative blockchain with 6-second finality, negligible fees ($0.001/tx), and a growing ecosystem of AI-native protocols. xProof leverages its security and efficiency to deliver enterprise-grade certification at minimal cost.

Why It Matters -- Real Scenarios

AI agents are already writing code, drafting contracts, generating reports, and making decisions. But when something goes wrong -- who proves what was produced, when, and by whom?

xProof is the answer layer.

"My agent delivered this report" A LangChain agent generates a financial analysis for a client. xProof certifies the output before delivery. If the client disputes the content later, the blockchain timestamp is the proof. Irrefutable. No he-said-she-said.

"This build was not tampered with" Your CI/CD pipeline compiles and ships. xProof's GitHub Action certifies every artifact automatically. Six months later, a security audit asks: "Is this binary what you deployed?" -- one hash check, case closed.

"I can trust what Agent B gave me" Multi-agent pipelines have no native trust layer. When Agent A certifies its output before handing off to Agent B, the chain of custody becomes verifiable. Agents can prove they did their job. Pipelines become auditable end-to-end.

"Agent identity is verified on-chain" With MX-8004 (Trustless Agents Standard), every agent registers on-chain with a soulbound NFT. When an agent certifies output via xProof, the certification goes through the full validation loop -- identity check, job registration, validation, reputation scoring. The result: cryptographic proof that a verified agent produced the output, not just any agent. Trust is no longer assumed -- it's proven.

"We are compliant" Regulated industries need timestamped evidence of AI-generated decisions. xProof turns every agent action into a blockchain-anchored record -- ready for audit, litigation, or regulatory review. Zero extra work.

"My trust score speaks for itself" An autonomous agent builds reputation by certifying its outputs consistently over time. Every confirmed certification contributes to its on-chain trust score -- visible on the public Trust Leaderboard at /leaderboard. Clients and peer agents query /api/trust/{wallet} before engaging. Trust becomes mathematical, not reputational.

Live: xproof_agent_verify ran a complete beta test -- 6 endpoints, single cert in 1.075s, batch of 3 in 1.876s, on-chain verification in 198ms. Now on the leaderboard: Active, score 157. Proof • Full review

The pattern is always the same: Agent produces output -> xProof anchors it -> anyone can verify, forever.

Pricing

$0.01 per certification — flat rate. No tiers, no subscriptions, no monthly fees.

Current pricing: https://xproof.app/api/pricing

Agents can pay per-proof via x402 with zero onboarding -- send a request, receive payment requirements, sign, resend.

Quick Start

Use the API (fastest)

# Certify a file in one call
curl -X POST https://xproof.app/api/proof \
  -H "Authorization: Bearer pm_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "file_hash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
    "filename": "report.pdf",
    "author_name": "Your Name"
  }'

Response:

{
  "proof_id": "uuid",
  "status": "certified",
  "file_hash": "e3b0c44...",
  "verify_url": "https://xproof.app/proof/uuid",
  "certificate_url": "https://xproof.app/api/certificates/uuid.pdf",
  "proof_json_url": "https://xproof.app/proof/uuid.json",
  "blockchain": {
    "network": "MultiversX",
    "transaction_hash": "txhash...",
    "explorer_url": "https://explorer.multiversx.com/transactions/txhash..."
  }
}

Use the Web App

Go to xproof.app, connect your MultiversX wallet, drop a file, certify. Done.

Self-Host

git clone https://github.com/jasonxkensei/xproof.git
cd xproof
npm install
cp .env.example .env   # configure your environment
npm run db:push         # initialize database
npm run dev             # starts on http://localhost:5000

Prerequisites: Node.js 20+, PostgreSQL (or Neon), MultiversX wallet.

See docs/environment-variables.md for configuration details.

For Developers

POST /api/proof -- Single Certification

Certify one file hash on-chain in a single API call.

curl -X POST https://xproof.app/api/proof \
  -H "Authorization: Bearer pm_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "file_hash": "<64-char-sha256-hex>",
    "filename": "output.txt",
    "author_name": "Agent Name",
    "webhook_url": "https://your-server.com/webhook"
  }'

POST /api/batch -- Batch Certification

Certify up to 50 files in a single call.

curl -X POST https://xproof.app/api/batch \
  -H "Authorization: Bearer pm_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "files": [\
      {"file_hash": "<hash1>", "filename": "file1.txt"},\
      {"file_hash": "<hash2>", "filename": "file2.py"}\
    ],
    "author_name": "Agent Name"
  }'

Verification

Webhooks

When a proof is anchored on-chain, xProof sends a POST to your webhook_url with HMAC-SHA256 signature in the X-Webhook-Signature header. Retry policy: 3 attempts with exponential backoff.

API Keys

Generate API keys from the Settings page after connecting your wallet. Keys use the pm_ prefix and support per-key rate limiting.

For Agents

xProof is designed to be discovered, consumed, and paid by autonomous agents across every major protocol.

Universal Compatibility

x402 -- Pay Per Proof, No Account

Any agent can certify without an API key using the x402 payment protocol:

1. Send POST /api/proof without auth

2. Receive HTTP 402 with payment requirements (USDC on Base, eip155:8453)

3. Sign the payment and resend with X-PAYMENT header

4. Receive the proof

$0.01 per certification — flat rate. Current pricing: https://xproof.app/api/pricing. No signup. No API key. No account.

MCP -- Model Context Protocol

xProof exposes a live MCP server at POST /mcp with two tools:

• certify_file -- certify a file hash on MultiversX

• verify_proof -- verify an existing certification

Any MCP-compatible agent can discover and call these tools directly.

ACP -- Agent Commerce Protocol

Full commerce flow for programmatic purchasing:

GET  /api/acp/products       # Discover products and pricing
GET  /api/acp/openapi.json   # OpenAPI 3.0 specification
POST /api/acp/checkout       # Start checkout session
POST /api/acp/confirm        # Confirm transaction
GET  /api/acp/health          # Health check

MX-8004 -- MultiversX Trustless Agents Standard

xProof is natively integrated with MX-8004, providing:

• Identity Registry -- agent registration with soulbound NFTs

• Validation Registry -- full validation loop for certifications reaching "Verified" status on-chain

• Reputation Registry -- cumulative on-chain reputation scoring with feedback

• Persistent TX Queue -- PostgreSQL-backed transaction queue with nonce management and exponential backoff retry

Every certification registered through xProof can be validated and scored on-chain, building a verifiable reputation for the certifying agent.

Conway/Automaton Skill

xProof ships a ready-made skill for Conway Automatons:

skills/xproof/SKILL.md

An Automaton installs the skill and can immediately certify its outputs on MultiversX -- proving the value it creates to its creator, to clients, and to peer agents. This aligns directly with the Automaton survival-by-work model.

Agent Trust Leaderboard

Every certification builds cumulative on-chain reputation. The Trust Leaderboard makes it public and discoverable.

• Pages: /leaderboard — public, sortable, filterable. /agent/{wallet} — individual profile with stats, streak, and recent certs timeline.

• Trust Score: confirmed_certs × 10 + last_30d × 5 + seniority_bonus (max 150) + streak_bonus (consecutive weeks × 8, max 100)

• Trust Levels: Newcomer (0–99) → Active (100–299) → Trusted (300–699) → Verified (700+)

• Opt-in: Configure your public profile via Settings or PATCH /api/user/agent-profile

• Trust Badge: Embed in any README — GET /badge/trust/{wallet}.svg returns a dynamic shields.io-style badge showing current level and score

Live example — xproof_agent_verify: Beta-tested all 6 API endpoints. Single cert: 1.075s. Batch (3 files): 1.876s. On-chain verification: 198ms. Now on the leaderboard — Active, score 157, 10 confirmed certs.

• Proof: f8c3b35d-6ee1-4f76-a92b-1532a008df7b

• Full review: moltbook.com

OpenClaw Skill

ClawHub-standard skill for the OpenClaw ecosystem:

• Repository: github.com/jasonxkensei/xproof-openclaw-skill

• Includes SKILL.md, certify.sh, and full API reference

GitHub Action

Integrate xProof into your CI/CD pipeline:

- uses: jasonxkensei/xproof/github-action@main
  with:
    api_key: ${{ secrets.XPROOF_API_KEY }}
    files: dist/**

Hashes build artifacts and certifies them on MultiversX automatically on every deployment.

See github-action/README.md for full documentation.

How It Works

User/Agent                    xProof                     MultiversX
    |                           |                           |
    |  1. Submit file hash      |                           |
    |     (API / Web / MCP)     |                           |
    |-------------------------->|                           |
    |                           |                           |
    |  2. SHA-256 validated     |                           |
    |     (client-side or API)  |                           |
    |                           |                           |
    |                           |  3. Transaction signed    |
    |                           |     & broadcast           |
    |                           |-------------------------->|
    |                           |                           |
    |                           |  4. Anchored on-chain     |
    |                           |     (6s finality)         |
    |                           |<--------------------------|
    |                           |                           |
    |  5. Proof returned        |  6. MX-8004 validation    |
    |     (JSON + PDF + URL)    |     registered            |
    |<--------------------------|-------------------------->|
    |                           |                           |
    |  7. Webhook notification  |                           |
    |     (HMAC-signed)         |                           |
    |<--------------------------|                           |

Core Capabilities

API Reference

Full documentation: docs/api-reference.md

Core Endpoints

Authentication

Agent Commerce Protocol

API Key Management

License

Proprietary — source available. See LICENSE.