@caypo/canton-gateway

MPP API gateway — pay-per-request access to OpenAI, Anthropic, and 15+ services with Canton USDCx

No API keys needed. Agents pay per request with USDCx on Canton Network via the Machine Payments Protocol (MPP).

Services

| Service | Endpoints | Price | Category | |---------|-----------|-------|----------| | OpenAI | chat, embeddings, images, transcription, speech | $0.001 – $0.05 | AI / LLM | | Anthropic | messages | $0.01 | AI / LLM | | fal.ai | image gen, stable diffusion, whisper, video, TTS | $0.01 – $0.10 | AI / Media | | Firecrawl | scrape, crawl, map, extract | $0.005 – $0.02 | Data | | Google Gemini | chat, reasoning, embeddings | $0.005 – $0.02 | AI / LLM | | Groq | chat, embeddings | $0.001 – $0.005 | AI / LLM | | Perplexity | chat with search | $0.01 | AI / Search | | Brave Search | web, images, news, videos, suggest | $0.001 – $0.005 | Search | | DeepSeek | chat | $0.005 | AI / LLM | | Resend | send, batch email | $0.005 | Communication | | Together AI | chat, embeddings, images | $0.001 – $0.02 | AI / LLM | | ElevenLabs | TTS, voice clone | $0.02 – $0.05 | Audio | | OpenWeather | current, forecast | $0.001 | Data | | Google Maps | geocode, places, directions | $0.005 | Data | | Judge0 | execute code, languages | $0.002 | Developer | | Reloadly | gift cards | $0.01+ | Commerce | | Lob | postcards, letters, address verify | $0.01 – $0.50 | Mail |

How It Works

1. Agent sends request     →  POST /openai/v1/chat/completions
2. Gateway returns 402     ←  WWW-Authenticate: Payment method="canton" ...
3. Agent pays on Canton    →  TransferFactory_Transfer (USDCx)
4. Agent retries + cred    →  Authorization: Payment <credential>
5. Gateway verifies        →  Fetches transaction from Canton ledger
6. Gateway proxies         →  Forwards to OpenAI with API key
7. Agent receives          ←  200 OK + Payment-Receipt + response

Discovery

curl https://mpp.caypo.xyz/api/services   # JSON catalog
curl https://mpp.caypo.xyz/llms.txt       # Agent discovery
curl https://mpp.caypo.xyz/health          # Health check

Use as Library

import { app } from "@caypo/canton-gateway";

// app is a Hono instance — use with any compatible server
export default app;

Self-Host

cd apps/gateway-server
docker compose up -d

Required env vars: GATEWAY_PARTY_ID, CANTON_LEDGER_URL, CANTON_JWT, and API keys for each upstream service.

License

Apache-2.0 OR MIT