Now Live · API v0.1.0

Tamper-Proof Receipts
for AI Agents

Cryptographically signed, GPS-tagged, server-timestamped proof of action. Built for AI agents, apps, and platforms that need trust.

Get Started Free → View Live API ↗
// POST /receipt — create a tamper-proof receipt   {   "success": true,   "receipt_id": "9f3a1c2d-...",   "hash": "sha256:a8f3c...",   "server_timestamp": "2026-03-27T20:00:00Z",   "gps": { "lat": 37.77, "lng": -122.41 },   "verify_url": "https://proofagent.pro/receipt/..." }   ✓ Authentic and unmodified.
SHA-256
Hash Algorithm
<100ms
Receipt Creation
0
Trust Required
100%
Tamper-Evident
How it works

Proof of action,
in three steps.

Any AI agent or app can generate a cryptographic receipt in milliseconds. No trust required — the math does the work.

01

Submit an Action

Your agent or app sends a POST request with the action data, optional GPS, and an optional photo. Camera captures are enforced server-side.

02

We Timestamp & Sign

Server sets the timestamp — clients cannot fake timing. An HMAC-SHA256 hash is built over all fields. Any edit breaks the hash.

03

Verify Anytime

Share the verify URL or receipt ID. Anyone can check authenticity instantly with a POST to /verify. No login needed to verify.

Features

Built for trust
at every layer.

Every detail is designed to prevent spoofing, backdating, and tampering.

⏱️

Server-Side Timestamps

Timestamps are always set by the server. Clients cannot submit a receipt with a fake time.

🔐

HMAC-SHA256 Hashing

Every receipt field is included in the hash. Change one byte — the verification fails.

📸

Image Integrity

Photo bytes are hashed before compression. Swapping an image after the fact is detected instantly.

📍

GPS Verification

Attach GPS coordinates to any receipt. Accuracy radius included — no fake location claims.

🔒

Immutable Records

Receipts have no PUT or PATCH endpoints. Once created, they cannot be modified.

Simple REST API

POST to create, GET to retrieve, POST /verify to authenticate. Works with any stack in minutes.

Pricing

Start free.
Scale when ready.

No credit card required to get started. Upgrade when your usage grows.

Free
$0 /month
Perfect for building and testing your integration.
  • 500 receipts / month
  • GPS + timestamp verification
  • Image integrity checks
  • Public verify URLs
  • REST API access
Get Started →
Enterprise
Custom
For platforms needing volume, compliance, or white-labeling.
  • Unlimited receipts
  • Self-hosted option
  • SOC2 / compliance docs
  • Dedicated support
  • Custom integrations
  • White-label API
Contact Us →

Ready to add trust
to your AI stack?

One API. Tamper-proof receipts. No trust required.

Get Your API Key →