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
8 endpoints charge more than they advertiseworst: api.micropay.website/api/v1/images/generations lists $0.01, demands $0.50 (50×)

10 merchants · 53 endpoints

arbsignal-production.up.railway.app

Markets & trading3 endpoints

ArbSignal — live cross-DEX arbitrage scanner for Algorand. Finds asset pairs priced differently across DEXes (Tinyman, Pact, HumbleSwap, Folks) and returns the profitable gaps, ranked by NET spread % (after both pools' swap fees). Each opportunity names the cheapest pool to BUY the base asset and the richest pool to SELL it, with pool IDs, protocols, prices, fees, and liquidity. Empty/outlier/dust pools are filtered out. Spreads are spot (pre-slippage) — check executable size before trading. Optional query ?minNet=<pct> sets the minimum net spread to report (default 0.5). Try it in the browser: https://arbsignal-landing.vercel.app

100%live462paid calls4payers
$0.001 – $0.002
USDC
Verified3/3 answered · 20h ago

api.iomarkets.ai

Markets & trading4 endpoints

Signed point-in-time price attestation

100%live215paid calls5payers
$0.001 – $0.50
USDC
Verified4/4 answered · 19h ago

oyapicks.app

Markets & trading10 endpoints

OyaPicks: same outcome priced differently across Polymarket and Alpha Arcade (cross-venue gaps)

100%live160paid calls22payers
$0.01 – $0.25
USDC
Verified10/10 answered · 20h ago

api.algometrics.org

Markets & trading10 endpoints

ALGO-USD market microstructure metrics from Coinbase trade data: VPIN (flow toxicity) and order-flow imbalance

100%live94paid calls7payers
$0.01 – $0.05
USDC
Verified10/10 answered · 20h ago

amarok-api.compx.io

Markets & trading6 endpoints

Amarok unsigned execution quotes

100%live78paid calls2payers
$0.05 – $0.25
USDC
Verified6/6 answered · 19h ago

Cursor-based delta poll over watched wallets and tokens. Change types: wallet_activity (tx count + largest transfer since cursor; algorand/ethereum/base), token_risk_change, token_liquidity_shift, token_holder_shift (~10-min granularity; all five chains). First poll establishes baselines. Empty deltas still ran the query

100%live14paid calls3payers
$0.01 – $0.12
USDC
Verified11/11 answered · 19h ago

rampa-x402-production.up.railway.app

Markets & trading5 endpoints

Withdrawal fees per exchange for a crypto asset, by network, ranked cheapest-first — plus the taker trading fee where known and a shortcut of which exchanges support ALGORAND-network withdrawals. Use to minimize the real cost of moving funds off an exchange

100%live10paid calls1payer
$0.01 – $0.05
USDC
Verified5/5 answered · 20h ago

roam402.com

Markets & trading2 endpoints

Machine-readable catalog of 50+ verified x402 services callable through this merchant — LLM inference, token security, market data — each with USDC price, Agents-Trust tier and liveness. Same payload is free at /catalog; this paid twin exists so the index itself is a discoverable x402 resource

100%live6paid calls2payers
$0.0001 – $0.0005
USDC
Verified2/2 answered · 20h ago

agent402.tools

Markets & trading1 endpoint

Describe a task (or name a slug) and the Smart Order Router resolves the best-matching tool and RUNS it in the same call - flat $0.05 covering any tool listed at $0.04 or less, from THIS host's catalog or any external x402 seller in the open index

100%live4paid calls3payers
$0.05
USDC
Verified1/1 answered · 19h ago

dipbuyerx402-production.up.railway.app

Markets & trading1 endpoint

A cryptographically-signed, on-chain-anchored Peter Lynch decision proof for a stock (?symbol=AAPL)

100%live2paid calls2payers
$0.01
USDC
Verified1/1 answered · 20h ago