AI agent verification — Know Your Agent (KYA)

Why agents need it

Why AI agents need a verified human.

Agents act for people

They book, buy and post on someone’s behalf. That someone should be real.

Services need to know who’s accountable

Before you act on a request, confirm a verified person stands behind it.

A seal anyone can check offline

One public key, ES256. No call to 5arz is needed to check it.

How KYA works

From agent to proof in four steps.

Step 1
Your agent
Asks to prove a person stands behind it.
tools/call
Step 2
mcp.5arz.com
Checks the agent’s owner is a verified person.
verify_human
Step 3
pop_jwt
A signed token comes back to the agent.
ES256 · 5arz-oracle-2
Step 4
The service
Checks it offline with our public key.
valid ✓

Press Play to watch a request go through.

Get started

Two ways to register an agent.

Option AOver MCP

Let your agent register itself

Add our MCP server. Your agent calls register_agent and gets a free-plan key.

mcp config · JSON

{
  "mcpServers": {
    "5arz": {
      "url": "https://mcp.5arz.com"
    }
  }
}

Listing tools needs no key. 10 tools in total.

Option BIn the browser

Register it yourself

Name your agent and get a key in a minute. Free plan, no card.

Your keysStatus

arz_test_••••••••Test key · free sandboxIssued right away

arz_live_••••••••Live key · Free plan to startIssued right away

Register in the browser

Model Context Protocol + REST

Works with any MCP or HTTP client

Call 5arz from any framework that speaks MCP or HTTP.

Claude
LangChain
CrewAI
AutoGen
LlamaIndex
Vercel AI SDK
OpenAI Agents SDK
Semantic Kernel

9

MCP tools

32

API endpoints

ES256

signatures

Free

to start

The 9 MCP tools at mcp.5arz.com

Listing tools needs no key.

register_agentCreate an API key from a name and contact email. mode: "test" gives a free sandbox key.
verify_humanMint a signed PoHF credential: a person did this work, or a verified human is behind an account.
check_credentialVerify a pohf_jwt, pop_jwt or sd_jwt_vc (SD-JWT VC) against our key. No API key.
get_vhh_indexThe Verified-Human-Hour index: a USD per hour benchmark. Free.
subscribeGet a Stripe checkout link for a plan.
get_balanceYour plan and usage.
list_verified_human_tasksVerified human tasks agents can buy: price, slots, chains. Free.
purchase_verified_human_taskBuy one task slot over x402 and get an attestation_id.
get_attestation_receiptFetch a PoHF receipt by attestation id. Free.

Machine-readable: agent manifest · OpenAPI · public key (JWKS) · MCP guide

Payments

Paying from an agent.

Developer preview · testnet

Buy verified-human tasks with x402

Agents can buy listed verified-human tasks over x402, paying USDC inside an HTTP 402 response. Runs on Base Sepolia (testnet) today.

HTTP 402 · USDC · Base Sepolia

Coming soon

Hire a verified person from your agent

Not open yet. We’ll tell you when it is.

Get notified

FAQ

Questions about KYA

More detail lives in the docs.

Read the docs

What is Know Your Agent?

KYA is a check that a verified person stands behind an AI agent. A service can confirm it before acting on the agent’s request.

What’s a pop_jwt?

A signed token (ES256) that says a verified person stands behind this agent. Anyone can check it offline with our public key.

Does my agent need a person?

Registering needs only a name and a contact email. To get a pop_jwt, that person verifies once with our partners.

Does a seal prove one account per person?

No. A seal proves a verified person is behind it, not that they hold only one account. Read sybil_checked in the claims before gating one-per-person actions.

Can I get it as an SD-JWT VC?

Yes. The same claims come as sd_jwt_vc, the IETF SD-JWT VC format. check_credential verifies it, no API key needed.

Is it free?

Free to start: 1,000 seals a month with API and MCP access, no card. Checking any seal is always free.

Give your agent a verified human.

Free to start. Checking a pop_jwt is always free.

Register an agent Read the docs

Prove a real person stands behind your AI agent.