402 402Signal

Find a paid API that works right now.

Independent signal an agent checks immediately before spending. Discovery listings are claims. 402Signal reports what the endpoint actually returned. Routing never waits for chain.

Base · Solana · Algorand

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$0.01 USDC per live routing check · your agent keeps the wallet.

DISCOVERY

What catalogs claim

Listings and seller metadata. A claim can outlive the endpoint.

402SIGNAL

Check it now

  1. DISCOVER Find candidates
  2. PROBE Check the endpoint now
  3. OBSERVE Capture current x402 behavior
  4. COMPARE Apply constraints and rank

Valid x402? Payment terms? Invocation info? Fresh observation?

YOUR AGENT

Decide whether to spend

Own wallet. Sign. Pay the seller. Call the API.

EVIDENCE · asynchronous

  1. COMMIT Routing evidence enters an append-only Merkle log.
  2. SIGN 402Signal signs a checkpoint with its Ed25519 log identity.
  3. ANCHOR Algorand TestNet · Falcon-1024

The route is gold and synchronous. Evidence is teal and does not delay routing.

Discovery to 402Signal to your agent, with an asynchronous teal evidence path

A decision, with evidence

ROUTE

A live URL plus the observed payment option from this check.

EVIDENCE

What the check established: 402 envelope, terms, invocation info, freshness.

MISS

A typed miss instead of substituting an unverified service.

HISTORY

Commitments that can be verified later. Routing does not wait for chain.

PQ transparency · TestNet

Trust the history, too.

As agents start spending money on your behalf, there should be a record of what they relied on. 402Signal keeps a tamper-evident history of its routing evidence and periodically anchors that history to Algorand TestNet using Falcon-1024 authorization.

Latest anchor · Tree 13 · Block 66864432 · Confirmed

So if an agent pays for an API, research, or service, the evidence behind that routing decision can’t simply be rewritten later.

View transparency