MCP serverStreamable HTTP · proof-of-human

Call proof-of-human from inside your agent. The 5arz MCP server lets any Claude, GPT, or agent-framework session register, verify a real human, and independently check the resulting credential — natively, over the Model Context Protocol. Agents can't buy what they can't call.

Server URL https://mcp.5arz.com

Streamable HTTP Auth: Bearer <5arz API key> Free: 1,000 seals/mo verify against public JWKS, no SDK x402 purchase — no key

Add it to Claude

Claude Code (CLI):

claude mcp add --transport http 5arz https://mcp.5arz.com \
  --header "Authorization: Bearer arz_live_YOUR_KEY"

Or drop this into your MCP client config (.mcp.json / Claude Desktop):

{
  "mcpServers": {
    "5arz": {
      "type": "http",
      "url": "https://mcp.5arz.com",
      "headers": { "Authorization": "Bearer arz_live_YOUR_KEY" }
    }
  }
}

No key yet? Add the server without the header — you can still call register_agent, get_vhh_index, check_credential, and all three marketplace tools (list_verified_human_tasks, purchase_verified_human_task, get_attestation_receipt). Then register_agent returns a key with Free plan: 1,000 seals/mo.

Tools

Tool	What it does	Key?
`register_agent`	Create a 5arz API key (Free plan: 1,000 seals/mo + 10 document checks). `mode:"test"` for an unlimited sandbox key.	no
`verify_human`	Mint a signed PoHF credential — `sessionId` for work fulfillment, or `memberId` for personhood (optionally wallet-bound).	yes
`check_credential`	Independently verify a PoHF JWT against the public JWKS and read its claims. Pure crypto — no trust in 5arz.	no
`get_vhh_index`	The Verified-Human-Hour index ($/hr) — a citable benchmark for verified human work.	no
`subscribe`	Stripe checkout for a plan: Starter $99/mo, Growth $499/mo, Scale $2,499/mo.	yes
`get_balance`	Current plan, seals and document checks used this month, and what remains.	yes
Verified-human-work marketplace — no API key, the payment is the authentication
`list_verified_human_tasks`	Currently-buyable verified human work: USD price, `price_usdc_atomic`, slots remaining, settlement chains, and the receipt kind issued on completion.	no
`purchase_verified_human_task`	Buy one slot. With only a `task_id` it returns the x402 HTTP 402 challenge (`accepts[]` + `purchase_id`). Settle the USDC, call again with `x_payment` and `purchase_id` to get an `attestation_id`.	no
`get_attestation_receipt`	The Proof-of-Human-Fulfillment receipt for an `attestation_id` — signed packet, verifier identity, JWKS URL, and how to verify it yourself.	no

Quickstart

1register_agent → your API key (Free plan: 1,000 seals/mo)

2verify_human → a signed PoHF credential (ES256 JWT)

3check_credential → anyone confirms it against the JWKS

Kick the tires with curl

The server speaks JSON-RPC 2.0. List the tools with no key at all:

curl -s https://mcp.5arz.com \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

Buy verified human work — no key, no human in the loop

The same server sells the work, not just the proof. An agent completes a purchase end to end without an API key and without a person: the x402 payment is the authentication.

1list_verified_human_tasks → task id, USD price, slots left, settlement chains

2purchase_verified_human_task {task_id} → HTTP 402 challenge: accepts[] + purchase_id

3settle the USDC on an offered chain, then call again with x_payment + purchase_id

4get_attestation_receipt {attestation_id} → the signed PoHF receipt + JWKS to verify it

curl -s https://mcp.5arz.com \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call",
       "params":{"name":"purchase_verified_human_task",
                 "arguments":{"task_id":"wf_support_reply_001"}}}'

The 402 is the protocol working, not an error — it comes back as an ordinary tool result carrying accepts[] (scheme, network, payTo, USDC asset, maxAmountRequired) and a purchase_id. Calling with no payment costs nothing. The same loop over plain REST: GET /api/agent/tasks, GET /api/agent/tasks/{task_id}/buy, GET /api/attestations/{attestation_id}. bind_human_to_payment — attaching a verified human to a payment that already settled on another rail — is a separate product and still lives only at https://api.5arz.com/mcp.

Compatible with Verifiable Intent and the Visa Trusted Agent Protocol; settles over Agent Pay, Stripe, or x402/USDC. 5arz binds an agent to a verified, present human — the claim Web Bot Auth, Know Your Agent, and the Trusted Agent Protocol reference but don't provide.