xProof — Prove Before Act

Any agent. No account required. $0.01/proof flat.

Hash reasoning locally → anchor on MultiversX → get immutable proof_id → execute. Full 4W audit trail. Public verification. Violations layer. Trust score.

openclaw skills install @jasonxkensei/xproof

The Core Pattern

Hash (WHY) → Anchor → proof_id → Execute (WHAT) → Hash (result) → Anchor

Pre-execution commitment + post-execution result = tamper-proof 4W audit trail (Who / What / When / Why).

Pricing

$0.01 per proof — flat. No tiers, no volume discounts.

Payment: USDC on Base (x402, no account) · EGLD on MultiversX (ACP/wallet) · prepaid credits.

Quick Start

# Option A — Free trial (10 proofs, no wallet)
curl -X POST https://xproof.app/api/agent/register \
  -H "Content-Type: application/json" \
  -d '{"agent_name": "my-agent-001"}'
# → returns pm_ key — store it securely, never log or echo it

# Option B — x402 (USDC on Base, no account)
# WARNING: autonomous payments. Set a spending cap before enabling in production.

# Option C — Prepaid credits (wallet)
# Dashboard: https://xproof.app/dashboard

# Reference files (load once at install time, not at runtime)
mkdir -p .agent/skills/xproof/references
for f in certification x402 mcp; do
  curl -sL "https://raw.githubusercontent.com/jasonxkensei/xproof-openclaw-skill/main/xproof/references/${f}.md" \
    > ".agent/skills/xproof/references/${f}.md"
done

⚠️ Security & Privacy

Read this section in full before enabling this skill in any agent.

What leaves your environment

xproof receives only the fields you explicitly send: file_hash (SHA-256 hex), filename (a label you choose), and optional metadata fields. No raw content, no documents, no binary data are ever transmitted. Hash computation must happen locally using hashlib.sha256, crypto.subtle.digest, sha256sum, or equivalent before any API call.

The metadata fields (why, what, model_hash, etc.) are under your control. You decide what goes in them. Choose carefully:

• Safe to include: opaque IDs, hashed summaries, strategy labels, model version strings, decision category codes.
• Never include: raw prompts, chain-of-thought text, user PII, secrets, API keys, proprietary strategy details, confidential filenames, or regulated data. Even when only a hash is anchored on-chain, metadata submitted alongside it is stored and may be returned in public API responses.

Proof visibility and public records

• Trial users (register_trial / POST /api/agent/register): proofs are public by default (is_public: true). Anyone can look up your proof by hash or proof_id. Pass "is_public": false in the request body to create a private proof even during trial.
• Authenticated users (prepaid credits, wallet): proofs default to is_public: false. Set "is_public": true only when public verifiability is intentional.
• Once a proof is anchored on-chain, its blockchain record is permanent and cannot be deleted. Only the off-chain metadata visibility can be toggled.

API key (pm_) security

A pm_ key is a bearer credential — treat it exactly like a database password:

• Store it in a secret manager (env var, vault, secret store) — never hardcode it in source code.
• Never log it, echo it in chat output, persist it in agent memory files, or include it in trace exports.
• When register_trial returns a key in its response, redact or discard that value from any transcript or log immediately after storing it securely.
• Rotate the key immediately if you suspect it was exposed.

audit_agent_session — external persistent transmission

This tool transmits complete session content (input, reasoning steps, output) to a durable, external record at xproof.app.

Key implications:

• The record is designed to be immutable. Submitted session data cannot be deleted or amended after anchoring.
• Do not use this tool if your session contains user PII, secrets, regulated data (HIPAA, GDPR-sensitive), proprietary strategy, or confidential instructions.
• Prefer submitting a SHA-256 hash of the session + a high-level label rather than raw session content.
• Operator opt-in required: only call this tool when your deployment operator has explicitly configured session-level audit logging for compliance purposes.

x402 autonomous payments

x402 enables your agent to initiate USDC payments on Base without per-transaction human confirmation. This is intentional by design for autonomous agents, but requires explicit safeguards:

• Set a per-session spending cap in your agent framework before enabling x402. Without a cap, a looping agent can trigger repeated payments.
• Require human approval above your threshold (e.g. >$1 per session) before enabling x402 in production.
• x402 is opt-in: if your agent uses Authorization: Bearer pm_..., it will not trigger x402 payments. x402 only activates on unauthenticated calls that receive a 402 response and proceed to sign a payment payload.
• Isolate the wallet used for x402 from your main treasury. Use a dedicated wallet with a limited USDC balance.

Tool invocation scope

This skill's tools should be invoked only when your operator configuration explicitly requires proof anchoring for a given action type. Do not invoke certify_file or audit_agent_session by default on every action. Define a policy in your operator config specifying which action categories require anchoring (e.g. financial operations, data writes, external API calls) and gate invocation on that policy check.

Other security rules

• NEVER commit API keys to a public repository. ALWAYS add .env to your .gitignore.
• x402 and MCP endpoints perform real network calls to xproof.app. In air-gapped or restricted environments, verify that outbound HTTPS to xproof.app is permitted.
• llms.txt and llms-full.txt are static documentation references — load them once at install time, not at runtime on every call. Dynamic fetching creates a prompt-injection surface if the file is ever compromised upstream.

Core Tools

certify_file — Anchor a hash on-chain

Invoke only when your operator policy requires proof anchoring for this action type.

import hashlib, json

# Step 1: compute hash LOCALLY — never send raw content
content = json.dumps({"decision": "execute_trade", "rationale_id": "r_abc123"},
                     sort_keys=True).encode()
file_hash = hashlib.sha256(content).hexdigest()

# Step 2: anchor hash + opaque metadata (no raw reasoning text)
proof = client.certify(
    file_hash=file_hash,
    filename="decision_2026_001.json",
    metadata={
        "role": "WHY",
        "action_type": "trade_execution",
        "model": "gpt-4o-mini",
        # DO NOT put raw prompt, strategy text, or PII here
    },
    is_public=False   # default to private unless public verifiability is required
)
proof_id = proof["proof_id"]

audit_agent_session — Log a complete session

⚠️ Transmits complete session data to a durable external record. Operator opt-in required. Prefer hashing session content and submitting the hash via certify_file.

# Safer alternative: hash the session, anchor the hash
session_hash = hashlib.sha256(json.dumps(session_data, sort_keys=True).encode()).hexdigest()
proof = client.certify(file_hash=session_hash, filename="session_audit.json",
                       metadata={"session_id": "s_xyz", "agent": "my-agent"})

investigate_proof — Look up an existing proof

Read-only. No records created, no payments triggered.

curl https://xproof.app/api/proof/<proof_id>

register_trial — Get a free pm_ key (10 proofs, no wallet)

curl -X POST https://xproof.app/api/agent/register \
  -H "Content-Type: application/json" \
  -d '{"agent_name": "my-agent"}'
# { "api_key": "pm_...", "trial": { "quota": 10, "remaining": 10 } }
# ↑ treat this value as a secret — do not echo, log, or persist in plaintext

4W Audit Trail

Trust Score & Violations

GET https://xproof.app/api/agents/{wallet}               # trust profile (public)
GET https://xproof.app/api/agents/{wallet}/violations    # violation audit
GET https://xproof.app/api/agents/{wallet}/incident-report?proof_id={id}  # 4W reconstruction

Trust score is computed from certification count, streak, and violation history. Violations are recorded automatically when structural anomalies are detected (time-ordering gaps, missing pre-execution anchors, burst patterns).

Command Cheatsheet

# Hash locally — original content must never leave your environment
sha256sum myfile.pdf | awk '{print $1}'

# Anchor via REST (is_public: false recommended for non-trial)
curl -X POST https://xproof.app/api/proof \
  -H "Authorization: Bearer pm_..." \
  -H "Content-Type: application/json" \
  -d '{"file_hash":"<sha256hex>","filename":"action_001.json","is_public":false}'

# Anchor via MCP
curl -X POST https://xproof.app/mcp \
  -H "Authorization: Bearer pm_..." \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"certify_file","arguments":{"file_hash":"...","filename":"action.json","is_public":false}}}'

# Verify
curl https://xproof.app/api/proof/<proof_id>

# Badge (embed in README)
![xProof](https://xproof.app/badge/<proof_id>)

# Batch (max 100 per call)
curl -X POST https://xproof.app/api/batch \
  -H "Authorization: Bearer pm_..." \
  -d '{"files":[{"file_hash":"...","filename":"a.json"},{"file_hash":"...","filename":"b.json"}]}'

# Health
curl https://xproof.app/api/acp/health

Discovery Endpoints

Full specification: AGENT_PROOF_STANDARD.md