Omnicost
https://omnicost.com/api/v1/itemsConstruction unit prices with source and date for Spain, the US and the EU. OAuth or API key.
Paid verification
How it worksNo sponsored paid call yet.
Pay this endpoint once from your own wallet (Base USDC, up to $1.00) and we call it and record what came back. Your wallet pays the listed recipient directly; Agent Tools never holds funds. Sponsored checks prove delivery; they do not count as demand.
Quality grade
How grading works- ✓ Answers a real HTTP 402 challenge
- ✓ Publishes a /.well-known/x402 descriptor
- ✓ Payment address on record
- ✓ Settlement network declared
- ✓ Price declared
x402 readiness
Readiness is how fully this listing follows its protocol and how it behaved in our probes over 30 days. It is shown for reference and does not move it in search. Search order and leaderboards use the separate quality grade (here C+, 52.2/100), which weighs availability, payability and on-chain demand. How the two differ
| Valid payment requirements | 10/10 | Payment requirements carry a payee, a mainnet network and a price. |
| Live 402 challenge | 20/25 | Endpoint reachable; its 402 challenge was seen earlier (1241 ms). |
| x402 version | n/a | x402 version not observed yet. |
| Signed descriptor | n/a | No x402 standard defines a signed descriptor. |
| Uptime (30 days) | 15/15 | 11/11 probes succeeded over 30 days (100%). |
| Resource declaration | 10/10 | Declares 9 paid resource(s). |
| Verified identity | 5/10 | Publisher descriptor (/.well-known/x402 or OpenAPI) on record; claim this listing to verify domain control. |
| Freshness + modern flags | 5/5 | seen in a source within 7 days; declares x402. |
| Security declaration | n/a | Payment is the access control for an x402 resource. |
Compared with peers
Against 10,082 reachable x402 APIs in our daily snapshot (2026-11-12 06:46 UTC). Display only; it does not change search order.
- Readiness
- Higher than 75% of peers
- This listing 87 · peer median 78
- Latency
- Faster than 5% of peers
- This listing 1,241 ms · peer median 205 ms
Where it loses the most points, and how to win them back
- Live 402 challenge −5
— Answer the paid path with a valid 402 challenge.
Now: Endpoint reachable; its 402 challenge was seen earlier (1241 ms).
- Verified identity −5
— Claim the listing and prove control of its domain.
Now: Publisher descriptor (/.well-known/x402 or OpenAPI) on record; claim this listing to verify domain control.
Paid endpoints
9 resource(s) advertised by this origin. Each price below is that resource's own x402 price; the headline price is the range across them.
https://omnicost.com/api/v1/items
$0.0100 / call
Catalog items (JSON). With ?q= it is a search: $0.02.
https://omnicost.com/api/v1/items/{id}
$0.0100 / call
One canonical item with vendors and price history (JSON or Markdown)
https://omnicost.com/api/v1/search
$0.0200 / call
Semantic catalog search (JSON)
https://omnicost.com/api/mcp/x402
$0.0100 / call
MCP for x402 clients: tools/call (any tool) answers 402 without a key; initialize, tools/list and ping are free. Pay with a PAYMENT-SIGNATURE / X-PAYMENT header or params._meta["x402/payment"].
https://omnicost.com/api/mcp
$0.0100 / call
MCP tools/call (any tool) with an x402 payment header. Without a key, initialize, tools/list and ping are free; tools/call gets 401 unless the request carries a payment (OAuth sign-in or API key).
https://omnicost.com/en/catalog
$0.0100 / call
Catalog HTML for anonymous machines
https://omnicost.com/api/markdown/item/{id}
$0.0100 / call
Per-item markdown
https://omnicost.com/api/v1/agents/register
$0.1000 / call
Agent account + API key. See /auth.md
https://omnicost.com/register
$0.1000 / call
Browser signup is free; machines receive 402
How to call
curl -sS -i -X GET https://omnicost.com/api/v1/items # expect HTTP 402 Payment Required (about 0.01 USDC/call)https://omnicost.com/api/mcpListed in
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