SiloRail

Pay-per-call LLM API access over USDC on Monad.

What it is:

SiloRail is an OpenAI-compatible LLM gateway. Instead of creating an account or loading an API key, a wallet pays per request in USDC using HTTP 402 and x402.

The wallet signs a payment authorization, the facilitator pays gas, and every completed call has a public settlement receipt.

Choose a network before making API calls.

Use testnet for integration testing with testnet USDC and free OpenRouter models only. Use mainnet only when the payer intends to spend real USDC.

This apex host is an index, not a payment gateway. Do not send /v1 requests to silorail.com.

For agents: /llms.txt describes how to choose a network. /.well-known/silorail.json provides the structured index. /openapi.json describes this index host.

Monad testnet

API base: https://testnet.silorail.com
Network: eip155:10143
Chain ID: 10143
Money: testnet USDC; no monetary value
Model policy: only free, zero-priced OpenRouter models are available

Use this for integration testing. Paid OpenRouter models return 400 testnet_free_models_only.

Monad mainnet

API base: https://mainnet.silorail.com
Network: eip155:143
Chain ID: 143
Money: mainnet USDC; real value
Model policy: paid and free OpenRouter models are available

Use this only when the payer is prepared to spend real USDC.