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

# Agent Discovery with AIAX

> How an autonomous agent discovers and calls Invoica capabilities using the AIAX surface.

# Agent Discovery with AIAX

This guide walks through the exact steps an autonomous agent takes to discover Invoica and issue its first invoice.
No pre-configuration required — the agent only needs the base URL.

## Step 1: Fetch the manifest

```bash theme={null}
curl https://api.invoica.ai/.well-known/aiax.json
```

The manifest lists every available section. Pick the one you need, e.g. `create_invoice`.

## Step 2: Fetch the section

```bash theme={null}
curl https://api.invoica.ai/aiax/sections/create_invoice.json
```

The section returns the tool name, endpoint, method, input/output schema, and a worked example. No human docs needed.

## Step 3: Call the tool

The `create_invoice` tool uses x402 — the payment **is** the credential.

```bash theme={null}
# First call — server responds 402 with payment requirements
curl -X POST https://api.invoica.ai/api/x402/invoice \
  -H "Content-Type: application/json" \
  -d '{"issuer":"my-agent","recipient":"client-co","amount":5,"currency":"USDC"}'

# Second call — attach the payment header and retry
curl -X POST https://api.invoica.ai/api/x402/invoice \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <base64-encoded-payment>" \
  -d '{"issuer":"my-agent","recipient":"client-co","amount":5,"currency":"USDC"}'
```

On success: `{ "success": true, "capability": "invoice", "result": { "id": "...", "status": "PENDING" } }`.

## x402 payment flow

x402 is a standard micro-payment protocol on Solana. Agents pay **0.01 USDC** per invoice creation
via the PayAI facilitator — atomic with the invoice write, no separate settlement step needed.

For mandate queries (`query_mandate` section), no payment is required — that endpoint is public and free.

## See Also

* [AIAX Concepts](/concepts/aiax)
* [x402 Protocol](/concepts/x402-protocol)