Pay-per-call APIs

Endpoints an agent can buy one request at a time (Lightning L402, x402 USDC, MPP), sorted by price per call. Prices are read from the HTTP 402 challenge each endpoint returned to an unpaid request (nothing was paid). Sat prices use an approximate USD rate only for sorting and display.

endpoints that answered HTTP 402

535

one unpaid request each, nothing was paid

cheapest call

$0.0001

Object Storage: List objects

last probed

2026-10-24

prices are re-read from the live 402 challenge

Plain-English meanings

HTTP 402: “Payment Required”: a web status code a server sends when a request has to be paid for first.
L402: A way for an API to say “pay first”: it replies with a Lightning invoice, the agent pays a few sats, then gets its answer.
x402: The same pay-first idea for APIs, but paid in USDC (a dollar stablecoin) instead of Bitcoin.
MPP: Machine Payments Protocol: an open standard that lets agents pay for web services per request, with stablecoins or other payment methods.
USDC: A digital dollar: a crypto token meant to always be worth one US dollar.
sats: A satoshi (sat) is one hundred-millionth of a bitcoin.

Showing 535 of 535 endpoints

Protocol

Added

Object Storage: List objectsmppstablecoin402 seen 2026-10-23storage

provider: Tempo · method: GET

$0.0001USDC.e (MPP)

endpoint (not a link, to avoid accidental calls):

https://storage.mpp.tempo.xyz/

price basis: amount in the unpaid HTTP 402 Payment (MPP) challenge, USDC.e 6 decimals

“HTTP 402 + MPP Payment challenge (method=tempo): amount 100 atomic units of USDC.e (= $0.0001)”

source: storage.mpp.tempo.xyz/

last checked 2026-10-23

x402wrapperx402stablecoin402 seen 2026-10-18data

provider: x402-wrapper.onrender.com · method: GET

$0.0001USDC (x402)

endpoint (not a link, to avoid accidental calls):

https://x402-wrapper.onrender.com/v1/echo

price basis: USDC amount in the unpaid HTTP 402 payment challenge (first accepted option)

“HTTP 402 + x402 v2 challenge: amount 100 atomic units of USD Coin (= $0.0001)”

source: x402-wrapper.onrender.com/v1/echo

last checked 2026-10-18

Loop Gatewayl402lightning402 seen 2026-10-23ai/inference

provider: Loop XXI LLC · method: POST

1 sat≈ $0.0008

endpoint (not a link, to avoid accidental calls):

https://api.loopxxi.com/v1/chat/completions

price basis: invoice amount decoded from an unpaid HTTP 402 response

“HTTP 402 + L402 invoice for 1 sat(s)”

source: api.loopxxi.com/v1/chat/completions

last checked 2026-10-23

402 Index listed price: 1 sat (the probe value above is what is shown)

Raikiri: your first L402 purchase (1 sat test endpoint)l402lightning402 seen 2026-10-23l402/tools

provider: Raikiri · method: GET

1 sat≈ $0.0008

endpoint (not a link, to avoid accidental calls):

https://raikiri.org/v1/hello

price basis: invoice amount decoded from an unpaid HTTP 402 response

“HTTP 402 + L402 invoice for 1 sat(s)”

source: raikiri.org/v1/hello

last checked 2026-10-23

402 Index listed price: 1 sat (the probe value above is what is shown)

parsebit-lnd.fly.dev: Code explanation endpoint that accepts code or a code-file URL and rl402lightning402 seen 2026-10-23ai/code

provider: parsebit-lnd.fly.dev · method: POST

1 sat≈ $0.0008

endpoint (not a link, to avoid accidental calls):

https://parsebit-lnd.fly.dev/analyse/explain

price basis: invoice amount decoded from an unpaid HTTP 402 response

“HTTP 402 + L402 invoice for 1 sat(s)”

source: parsebit-lnd.fly.dev/analyse/explain

last checked 2026-10-23

402 Index listed price: 1 sat (the probe value above is what is shown)

parsebit-lnd.fly.dev: L402l402lightning402 seen 2026-10-23ai/text

provider: parsebit-lnd.fly.dev · method: POST

1 sat≈ $0.0008

endpoint (not a link, to avoid accidental calls):

https://parsebit-lnd.fly.dev/analyse/compare

price basis: invoice amount decoded from an unpaid HTTP 402 response

“HTTP 402 + L402 invoice for 1 sat(s)”

source: parsebit-lnd.fly.dev/analyse/compare

last checked 2026-10-23

402 Index listed price: 1 sat (the probe value above is what is shown)

AIsa MPP Data APIs: Airbnb: Search Airbnb Listingsmppstablecoin402 seen 2026-10-23data

provider: AIsa · method: GET

$0.0010USDC.e (MPP)

endpoint (not a link, to avoid accidental calls):

https://api.aisa.one/apis/v1/airbnb/search

price basis: amount in the unpaid HTTP 402 Payment (MPP) challenge, USDC.e 6 decimals

“HTTP 402 + MPP Payment challenge (method=tempo): amount 1000 atomic units of USDC.e (= $0.001)”

source: api.aisa.one/apis/v1/airbnb/search

last checked 2026-10-23

API Acre — Base block inspectionx402stablecoin402 seen 2026-10-23crypto

provider: API Acre · method: POST

$0.0010USDC (x402)

endpoint (not a link, to avoid accidental calls):

https://apiacre.com/v1/crypto/base-block-inspect

price basis: USDC amount in the unpaid HTTP 402 payment challenge (first accepted option)

“HTTP 402 + x402 v2 challenge: amount 1000 atomic units of USD Coin (= $0.001)”

source: apiacre.com/v1/crypto/base-block-inspect

last checked 2026-10-23

Agent402 hash (MPP) (x402)x402stablecoin402 seen 2026-10-23ai-tools

provider: Havok Holdings LLC · method: POST

$0.0010USDC (x402)

endpoint (not a link, to avoid accidental calls):

https://agent402.tools/api/hash

price basis: USDC amount in the unpaid HTTP 402 payment challenge (first accepted option)

“HTTP 402 + x402 v2 challenge: amount 1000 atomic units of USD Coin (= $0.001)”

source: agent402.tools/api/hash

last checked 2026-10-23

Agent402 stock-quote (MPP) (x402)x402stablecoin402 seen 2026-10-23ai-tools

provider: Havok Holdings LLC · method: GET

$0.0010USDC (x402)

endpoint (not a link, to avoid accidental calls):

https://agent402.tools/api/stock-quote

price basis: USDC amount in the unpaid HTTP 402 payment challenge (first accepted option)

“HTTP 402 + x402 v2 challenge: amount 1000 atomic units of USD Coin (= $0.001)”

source: agent402.tools/api/stock-quote

last checked 2026-10-23

showing 10 of 535 matches

USD rate used: $0.00081513 per sat (ratio of price_usd/price_sats in 402 Index API responses on 2026-10-15 (approximate, used only for sorting)).