402 Index
The paid API directory for AI agents — indexed, verified, and searchable
Ecosystem Overview
63,173
Endpoints Indexed
27,390
Payment-Verified
1,373
Providers Indexed
783
Providers Verified
L402 Lightning Network
Verified643 / 1,228 (52%)
Providers29 / 80 (36%)
Healthy643
Decentralized, censorship-resistant, locally verifiable
x402 Base, Solana, etc.
Verified26303 / 61,168 (43%)
Providers710 / 1223 (58%)
Healthy26699
Centralized facilitator required (4+ available), Base/Solana chains
MPP Stripe / Tempo
Verified444 / 777 (57%)
Verified (gateway-backed)163 / 378 (43%)
Providers51 / 99 (52%)
Healthy444
Stripe/Tempo facilitated, session-based settlement
Agent Discovery
Search the directory like an AI agent would through the MCP server
MCP Tool Call
{
"tool": "search_services",
"arguments": {}
}
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Live Endpoint Health Check
Paste any API URL to run a real-time health check — see the protocol handshake live
Payment Flow
How an agent pays for an API call — step by step
1
Agent Sends Request
Agent discovers endpoint via 402index and sends request
GET https://llm402.ai/v1/chat/completions
2
Server Returns 402
Server requires payment — returns 402 with payment instructions
WWW-Authenticate: L402 macaroon="AGIAJEem...", invoice="lnbc21n1..."
3
Agent Pays Invoice
Agent pays Lightning invoice automatically via lnget or wallet
Lightning BOLT11 invoice Amount: 21 sats Expiry: 60 seconds
4
Agent Retries with Token
Agent retries request with proof of payment
Authorization: L402 <macaroon>:<preimage>
5
Server Returns 200
Server validates payment and returns the requested data
HTTP/1.1 200 OK
Content-Type: application/json
{ "data": "..." }