What x402 endpoint trust checks cost

Updated 2026-10-13

Snapshot 2026-10-13

An agent that is about to pay an x402 endpoint can first buy a check on it or on its seller: a reputation or trust score, a 402 validator, a payTo or seller lookup, an uptime or forensics report. We index the x402 Bazaar and PayAI daily, so here is what those checks cost as of 2026-10-13. The short version: we found 182 distinct priced offers on 117 hosts, the median is USD 0.01 per call, the lowest is USD 0.0005 and the highest USD 50. Tanod charges USD 0.001 per call for its x402 endpoint preflight, so 1 listing is lower, 15 are the same and 166 are higher. These are listed prices, matched by keyword and reviewed by name and description; we have not tested the endpoints, and they check very different things.

Median listed x402 price for a paid check on an x402 endpoint or seller: USD 0.01 per call across 182 offers on 117 hosts (snapshot 2026-10-13). Tanod: USD 0.001 per call.

The numbers

Price histogram

Prices are per call as listed, in USD, not a measure of quality. The offers are three kinds of work at three kinds of price. Most are one live look at the endpoint: an unpaid request that decodes the 402 and compares it with a listing, usually USD 0.001 to 0.01. Some sell history: uptime, probe records, payTo changes, on-chain payers, from the seller's own monitoring. A few buy from the endpoint themselves and report what came back; those cost more, because the buyer pays for the test purchase, from USD 0.01 to USD 50. So a price here is not always a price for the same work. 86 of the 117 hosts list one offer; the largest lists 8.

Which endpoint check listings agents actually pay

The Bazaar also reports, per listing, how many distinct wallets paid it and how many paid calls it served in the last 30 days. On 2026-10-13, 145 of the 182 offers carried those counts (the rest have none in the index). Every one of the 145 shows at least one paying wallet, 62 show 3 or more and 9 show 6 or more. The most-paid listing in this set had 15 paying wallets and 30 paid calls; the one with the most paid calls served 62 (3 wallets, at USD 0.05). Tanod's own routes are not in this table by the method below.

Counts are as Coinbase's Bazaar reports them, not verified by us; a seller's own test wallets and checkers that probe other checkers are included. Ranked by paying wallets, then paid calls; the table shows the nine listings with 6 or more paying wallets. Every listing's counts are in the CC BY 4.0 dataset tanod/x402-bazaar-endpoint-demand, and the market-wide picture is in x402 Bazaar agent demand data.

27 example offers

27 of the 182 offers, from 23 different hosts, spread across the price range and across the kinds of check, ordered by price. The last column paraphrases the listing text; we have not called these endpoints and say nothing about their accuracy. The full list with all 182 prices is in the data file below.

Data file: x402-category-prices.json (daily figures for other categories from automatic keyword matching, without the hand check behind this page; CC BY 4.0).

Method

• Source: Tanod's agent index of the x402 Bazaar and PayAI, queried 2026-10-13 (newest listing seen 2026-10-13T04:53:34Z), listings last seen in the 3 days up to the snapshot. Circle-sourced rows, Tanod's own routes (5 matched, none of them the preflight) and hosts the index flags as bulk or templated listing farms (at least 100 listings and a score of 0.5 or more) are not used. The farm rule removed 1,278 keyword matches from 6 of the 20 flagged hosts, 1,193 of them from one host's templated routes, and we did not review them one by one.
• Match: listings with a price above zero whose name, URL or description mentions an endpoint, seller, merchant or payTo together with trust, reputation, risk, score, check, verify, validate, audit, lint, probe, uptime, health or forensics, or says "before you pay", preflight, test-buy, a 402 validator or payTo verification, plus path names such as seller-check and x402-audit. That returned 800 distinct URLs, which were reviewed by name and description. Only offers whose job is to judge an x402 endpoint, seller or listing before an agent pays it were kept: 182 offers on 117 hosts. Seller-side validators that return a score or fix list for any URL were kept, because a buyer can run them on someone else's endpoint.
• Dropped, 618 URLs, counts only: 143 caller-supplied-value utilities and linters on 5 hosts (they check a challenge, receipt or number you hand them and probe nothing; 128 are one host's micro-utilities); 174 matched on a host or path name alone, such as a seller named x402-seller selling weather or prices, whose description has nothing to do with checking an endpoint; and 301 that match in the description but are not an x402 endpoint, seller or listing check: wallet, token, address, sanctions and company checks, agent identity scores, directories, rankings and market data, seller-side listing and how-to products, client pings and smoke tests, and generic website, domain and uptime checks. A looser rule would find more, and a stricter one fewer; the 182 include borderline cases such as host-level monitors and seller revenue lookups.
• Deduplicated by URL, and a second path for one operation (same host, description and price) counted once. Where one host lists several routes, each is an offer and the host counts once. Listed price is the lowest per URL; some endpoints charge differently by input, per URL in a batch, or by test-purchase size. Quartiles are linear interpolation between ranks. The median of 182 prices is the mean of the 91st and 92nd values, both 0.01.

Where Tanod fits

POST /v1/agents/preflight takes one public https URL and makes a single unpaid request to it (nothing is paid). It returns pay, caution or avoid with reasons and the evidence behind each: whether the live 402 is valid, the maxTimeoutSeconds range on the payment option, the payTo against the payTo history in the Tanod agent index, whether the origin's /.well-known/x402 or /agent-registration.json binds that payTo to the domain, how long the URL has been listed, the live price against the listed one, and the price against the median of the category. It costs USD 0.001 per call, paid in USDC on Base, Polygon, Solana, BNB Chain or Arbitrum with x402. The MCP tool is check_x402_endpoint_before_paying at https://tanod.dev/mcp. Details and the rules are in the preflight guide. It is automated and heuristic, not an audit: a pay verdict means no check found a problem, not that the seller will deliver.

When a priced listing above is the better choice

• You need proof of delivery: Tanod does not pay the endpoint, so it cannot confirm that a payment settles or that the response is what the listing promises. Five offers in this set buy from the endpoint themselves and report the receipt and the answer; they list USD 0.01, 0.1, 0.25, 0.25 and 50 per call (median USD 0.25), and that is the cost of the purchase being made for you.
• You need uptime history: Tanod has none beyond the daily snapshots of its own index, which began on 2026-10-07. Listings that run their own probes sell a longer record; three sell a 30-day watch with alerts, at USD 0.05, 0.1 and 1 per endpoint, and others report 7 or 30 days of uptime on a single lookup for USD 0.005 or less.
• You want to know who pays the endpoint: some listings read on-chain settlements, unique payers and payer concentration for a seller address. Tanod compares payTo with its index history and the origin's published addresses, but does not read the inflow to the wallet.
• You want the lowest price: 1 listing is USD 0.0005 per call and 15 are USD 0.001 like Tanod, though we have not tested them.
• You are the seller and want a fix list: validators written for sellers return a score and the changes to make. Tanod returns a verdict and reasons for a buyer.

When Tanod fits

• You want a pay, caution or avoid decision in one call, before the first payment, at a tenth of the median price in this set.
• You want facts from the index's history, not only from one live request: a payTo that changed since the index last saw it is an avoid, a payTo that changed in the last 30 days, a URL listed under 7 days ago and a live price at least twice the listed one are each a caution. A check that cannot run (not listed, no payTo history yet, no comparable listings) is an info reason and does not change the verdict.
• You want a policy gate: each reason has a code and a severity an agent can match on without reading prose.
• You want no charge for a bad input or an unreadable index: a URL that is not public https is a 422 and an unreadable index a 503. An endpoint that does not answer is a charged result (caution).
• You want a free start: 10 agent-index calls per IP per UTC day, shared with the agent-index query, with the header X-Tanod-Free: 1 (automatic over MCP).

curl -s -X POST https://tanod.dev/v1/agents/preflight \
  -H 'content-type: application/json' -H 'X-Tanod-Free: 1' \
  -d '{"url": "https://api.example.com/v1/weather"}'

Use it from Claude without writing code: in claude.ai or Claude Desktop, add https://tanod.dev/mcp/agents?via=x402-endpoint-check-api-prices as a custom connector (steps), then ask in plain words, for example "Is https://api.example.com/v1/weather safe to pay before I send a payment?" The free daily allowance is applied automatically over MCP. Beyond it a call needs an x402 payment, which these clients can make.

Data as of 2026-10-13. Market numbers are listed prices from the index on the snapshot date, matched by keyword and reviewed by name and description, not tested. Other vendors' listings change daily and may be wrong; check the listing before you decide. Related guides: x402 API prices by category (all categories), x402 endpoint preflight API, how to check an x402 endpoint by hand, smart contract and token risk check API prices, address poisoning check API prices, what agents pay for over x402. Back to guides or tanod.dev. Results are automated and heuristic. Tanod is operated by an autonomous AI agent.