Free and sub-cent x402 APIs: what 'cheap' really means
How to find low-cost x402 tools without treating unknown prices, free overview calls and paid work as the same thing.
DIRECT ANSWER
Sub-cent x402 APIs can be useful for high-frequency agent workflows, but the displayed minimum may describe an overview tool rather than the work you need. Filter for a concrete price, inspect per-tool rows, request a live quote and calculate the full workflow cost. Missing pricing is not free, and a zero-dollar discovery call does not make every tool free.
Key takeaways
- Use per-tool prices where available instead of a single provider headline.
- Multiply price by retries, branches and expected calls per workflow.
- A spend policy should stop loops even when every individual call costs less than a cent.
Three different meanings of free
A template can be free to install, an overview tool can be free to call, and a service can have a free tier with paid work behind it. Those are not interchangeable. TOLL·402 displays template, tool and provider price evidence separately and uses 'varies' when the value cannot be supported.
| Label | Interpretation |
|---|---|
| Free template | No directory charge; you operate the infrastructure |
| Free tool | That named operation quotes zero |
| Free tier | Some usage is free under provider limits |
| Varies | No dependable numeric price is available |
Current low-cost examples
These are listed starting prices, not endorsements or guarantees. A recent quote check is stronger evidence than documentation alone, and a free or low minimum can apply to only one tool.
| Service | Listed minimum | Evidence | Caveat |
|---|---|---|---|
| melis.ai x402 Tools | from $0.0001/call | Provider documented | Tool prices extend above the minimum |
| Aigregator | $0.001/call | Quote checked | Check the exact operation before paying |
| PayAPI Market | $0.001/call | Quote checked | Gateway contains many underlying endpoints |
Use low-cost calls for evaluation
Cheap, read-only tools are good first candidates for wallet and policy testing. Keep the initial wallet balance small, pin the network, use explicit caps and log settlement receipts. Do not use low price as a reason to relax tool-permission or output-quality review.
Related directory entries
Sources and methodology
TOLL·402 distinguishes public claims, registry discovery, unpaid quote checks and settled paid-call verification. Sources below support the visible claims; presence in a registry is not treated as verification.
- TOLL·402 browse — Price filters and per-tool rows.
- x402 wallet concepts — Buyer wallet responsibilities.
- x402 buyer quickstart — Current payment client patterns.