Describe the job. Get the plan.
One paid call returns a call-ready plan over this catalog and outside x402 sellers with a recently verified 402: which tools, in what order, with fallbacks and params that validate. Run it yourself, or have Agent402 run it and the fee comes back as credit.
$0.005 to $0.05 per decision, paid per request in USDC over x402 or MPP. No account.
curl -X POST https://agent402.tools/api/decide \
-H "Content-Type: application/json" \
-d '{"task":"Check whether a wallet is on a sanctions list, then list its recent token transfers on Base","depth":"plan"}'
{
"decisionId": "dec_…",
"plan": [
{
"step": 1,
"purpose": "check the wallet against sanctions lists",
"tool": {
"slug": "sanctions-wallet",
"seller": "agent402",
"firstParty": true,
"endpoint": "/api/sanctions/wallet",
"priceUsd": 0.002,
"exampleParams": {
"address": "0x…"
}
},
"fallbacks": [
"…"
],
"dependsOn": []
},
{
"step": 2,
"purpose": "fetch recent token transfers on Base",
"tool": {
"slug": "asset-transfers",
"seller": "agent402",
"firstParty": true,
"endpoint": "/api/asset-transfers",
"priceUsd": 0.003,
"exampleParams": {
"address": "0x…",
"network": "base"
}
},
"fallbacks": [
"…"
],
"dependsOn": []
}
],
"estimatedCostUsd": 0.005,
"estimatedLatencyMs": 3000,
"confidence": 0.95,
"gaps": [],
"executionCredit": {
"amountUsd": 0.02,
"token": "dc_…"
}
}
How it decides.
A plan is only useful if you can trust why each tool is in it, so every step says why, every tool says whose it is, and the scoring is the same for everyone.
This catalog and outside sellers
This catalog plus outside x402 sellers, each with its price, rails, chains and input schema. Outside tools need a live 402 in the last 7 days.
One formula for every seller
Fit to the job, observed reliability, price, schema quality and a freshness pass mark, with the same weights for every tool and no term for who sells it.
Steps you can call
The job split into steps, each with a primary tool and fallbacks, params that validate against the tool's schema, and a cost and latency estimate. Gaps are named.
Yourself, or through us
Call the plan directly, or send it to /api/decide/execute. Outside steps are bought from the seller and resold at the seller's price plus a 5% markup, and the decision fee comes back as credit.
Three depths.
Priced by how much of the plan you want. Each decision's fee returns as a 100% credit, valid 24 hours, toward running it.
The single best tool for the whole job, with fallbacks.
The job split into steps, each with a primary tool, fallbacks and dependencies.
The plan plus params filled from your task, a compiled prompt to run it, and cost and latency estimates.
One formula, disclosed.
Our tools and every outside seller's are scored on the same five signals with the same weights, and the formula has no term for who sells a tool. The model that judges fit sees the same bounded description for every tool, and every tool in a plan carries firstParty, so the source is disclosed.
What we charge is on the page: the decision fee by depth, our tools at list price when a plan runs through us, and outside tools at the seller's price plus a disclosed 5% markup. Reliability counts what we observe, one observation per payer per day, and reports through /api/decide/feedback can move a tool only within a bounded range.
Connect.
Three routes, the same on every surface.
claude mcp add --transport http agent402 https://agent402.tools/mcp
Questions.
What does a decision return?
A plan: each step names its tool, endpoint, price, input params that validate against that tool's schema, and fallbacks. Plus a cost and latency estimate, a confidence score, and any needs no indexed tool covers (gaps). Depth "full" adds a compiled prompt an agent can run as is.
How are Agent402's own tools ranked?
By the same formula as every other seller's, with the same weights: fit to the step, observed reliability, price, schema quality and a freshness pass mark. The formula has no term for who sells a tool, the model that judges fit sees the same bounded description for every tool, and every tool in a plan carries firstParty, so you always see whose it is.
Which outside sellers can appear?
Outside x402 sellers (including sellers that also accept MPP) whose route answered a live 402 within the last 7 days and whose input schema is known. Anything the index cannot cover is listed in gaps.
Can a step use what an earlier step returned?
Yes. When a later step needs a value an earlier step produces (the address an ENS lookup resolved, say), the plan writes {{step N}} for it and lists that step in dependsOn. Run through POST /api/decide/execute, Agent402 fills it in from the earlier step's answer: a field with the parameter's name, or the one address or IP it returned. A value it cannot name without guessing skips that step, and nothing is paid for it.
Can execute run a free plan sketch?
Yes. /api/find and /api/route answer a multi-step task with a free sketch: one tool per step, chosen by keyword, no model. Send its execute body (the step slugs and your inputs for step 1) to POST /api/decide/execute and Agent402 runs the steps in order at list price; each later step takes its one required input from the step before. A paid decision adds judged fit, fallbacks, filled params and the credit.
How does the credit work?
The decision fee comes back as a credit worth 100% of it, valid 24 hours, toward running that plan with POST /api/decide/execute. Unspent budget from a run returns as credit until the same window closes.
What does running a plan cost?
Our tools at list price. Outside tools at the seller's price plus a 5% markup: we buy the result from the seller and sell it to you. Spend stops at your budget, fallbacks run in order, and a run where no step succeeds is not charged.