> ## Documentation Index
> Fetch the complete documentation index at: https://docs.meshrouter.app/llms.txt
> Use this file to discover all available pages before exploring further.

# First request

> Make a MESH request with curl, the OpenAI SDK, or a first-party SDK.

MESH keeps the OpenAI request shape and adds receipt headers, fallback routing, and per-call
[privacy classes](/privacy/mesh).

```bash theme={null}
curl https://api.meshrouter.app/v1/chat/completions \
  -H "Authorization: Bearer $MESH_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "mesh/claude-sonnet-4.5",
    "models": ["mesh/claude-opus-4.5", "mesh/llama-4-maverick"],
    "route": "fallback",
    "messages": [{ "role": "user", "content": "Summarize this document." }]
  }'
```

Read `usage.cost` in JSON responses and `x-mesh-receipt-id` in every routed response.