HashProof
Verifiable credentials with IPFS backup, on-chain registry, and pay-per-call API via x402.
What it is
HashProof is a credential issuance API. Organizations and Individuals (entities) issue verifiable credentials to people. Each credential is:
- Stored as a JSON in the database and backed up on IPFS (Pinata)
- Registered on-chain in the
CredentialRegistrycontract on Celo - Verifiable via a public URL:
https://hashproof.dev/verify/:id
Two ways to pay: micropayment in USDC via x402 (Base or Celo) — no API keys, no subscriptions — or a prepaid API key for enterprise clients (no crypto needed). AI agents can call the API directly using a funded wallet.
Project structure
backend/ Express API — credential issuance, verification, payments
frontend/ React app — landing page, credential verification, entity pages
contracts/ CredentialRegistry smart contract (Celo)
mcp/ MCP server (hashproof-mcp on npm) — use HashProof from any AI agent
skills/ Agent skill (npx skills add csacanam/hashproof)
docs/ Architecture and flow documentation
Deployed contracts
| Network | Contract | Address |
|---|---|---|
| Celo mainnet | CredentialRegistry | 0x7a1B759A602Aba72a70f99Dffd0a386d7504ce9B |
Paid API endpoints
| Endpoint | Price | Description |
|---|---|---|
POST /issueCredential | $0.10 USDC | Issue one verifiable credential |
POST /entities/:id/verificationRequests | $49 USDC | Submit a verification request |
Payment is in USDC on Base or Celo via x402. The client signs an off-chain authorization — no gas required.
Free endpoints
| Endpoint | Description |
|---|---|
GET /verify/:id | Full 3-layer verification |
GET /templates/:ref/requirements | Get required fields for a template |
POST /templates/:ref/preview | Generate a preview PDF with watermark (no cost) |
GET /stats | On-chain credential counters |
For AI agents
HashProof is fully agent-usable — no account, no human onboarding. Three ways in:
-
MCP server (listed on the official MCP registry as
io.github.csacanam/hashproof):claude mcp add hashproof -- npx -y hashproof-mcpTools:
preview_template(free — iterate custom layouts, PDF saved locally),issue_credential($0.10 via x402 or API key),verify_credentialandget_template_requirements(free). Seemcp/README.md. -
Agent skill:
npx skills add csacanam/hashproof— or read it at hashproof.dev/skill.md. -
Plain HTTP + x402:
POST /issueCredentialreturns a 402 challenge any x402-v2 client can pay (USDC on Base or Celo). LLM index: hashproof.dev/llms.txt.
Agent identity metadata (ERC-8004 registration-v1): hashproof.dev/metadata.json.
Quick start
See backend/README.md and frontend/README.md for setup instructions.
See docs/README.md for the full documentation index.