Assay

Every paid API on Algorand, tested rather than listed.

861 x402 endpoints from 39 merchants across 46 hosts — each one called on a schedule to check it answers, that its 402 challenge parses, and that it charges what it advertises.

Endpoints live
773
Open defects
85
Overcharging
8
Paid calls
28,684
Last sweep
19h ago · 100% covered
Buyer reviews
none yet
All categories4Security & risk0Markets & trading0Chain data1AI & inference1Web & documents0Infra & storage0Utilities2
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2 merchants · 522 endpoints · 4 endpoints charge above list, named below each merchant

agent402.tools

Utilities514 endpoints

Cryptographic hash of a text string. Algorithms: sha256 (default), sha512, sha1, md5. Returns hex and base64 digests

98%live2,089paid calls4payers
  • Price mismatch/api/answerlisted $0.03 · charges $0.08 (2.7×)
  • Price mismatch/api/skill/article-digestlisted $0.08 · charges $0.10 (1.3×)
$0.001 – $1.50
USDC
Pays elsewhere2 rerouted · 19h ago2 above list8 of 514 failing

second-opinion-production.up.railway.app

Utilities8 endpoints2 hosts

Second Opinion quick: an independent reasoning-only check (no web research) of your claim's logic and consistency with established knowledge. Honest 'inconclusive' when the claim needs live research

37%live23paid calls3payers
  • Price mismatch/v1/verifylisted $0.05 · charges $0.20 (4.0×)
  • Price mismatch/v1/verify/panellisted $0.25 · charges $0.75 (3.0×)
$0.03 – $0.25
USDC
Broken5 of 8 failing · 19h ago2 above list