# Agent buyer path — settle first USDC on Base x402

**v0.3.76** · enforce on · facilitator CDP live

> For agent wallets / clients that already want to **pay**. Free discovery lander is `/start`; external paste pack is `/share.md`. This page is the **first-buy settle recipe**.

## Payment constants

| Field | Value |
|-------|--------|
| payTo | `0xE79e7fa7Ce7259C46F9B127b837d2907Bb036F95` |
| Network | Base `eip155:8453` |
| Asset | USDC `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913` |
| Scheme | x402 `exact` |
| First pay | outline **0.01** USDC |
| Upgrade | brief **0.02** USDC |

## First funded call (outline 0.01)

```bash
# 0) free smoke (no wallet)
curl -s "https://x402.devvizion.com/v0/sample-outline?topic=x402"

# 1) unpaid probe — expect HTTP 402 + PAYMENT-REQUIRED / accepts[]
curl -s -i -X POST "https://x402.devvizion.com/v0/outline" \
  -H "content-type: application/json" \
  -d '{"topic":"x402 agent research"}'

# 2) build X-PAYMENT from 402 accepts (exact amount, payTo, network Base)
# 3) retry same POST with header:
#    X-PAYMENT: <base64 payment payload>
# 4) expect 200 markdown outline · settled on-chain to payTo
```

## MCP paid tool path

```json
{ "mcpServers": { "money-engine-x402": { "url": "https://x402.devvizion.com/mcp" } } }
```

| Step | Tool / path | Cost |
|------|-------------|------|
| free | **`x402_sample_outline`** · `x402_health` · `x402_discovery` | 0 |
| first pay | `x402_research_outline` / POST /v0/outline | **0.01** USDC |
| upgrade | `x402_research_brief` / POST /v0/brief | **0.02** USDC |

## Discovery (before pay)

- Machine pitch pack: https://x402.devvizion.com/pitch.json
- Catalog: https://x402.devvizion.com/.well-known/x402
- Merchant: https://api.cdp.coinbase.com/platform/v2/x402/discovery/merchant?payTo=0xE79e7fa7Ce7259C46F9B127b837d2907Bb036F95
- Share pack: https://x402.devvizion.com/share.md
- Skill: https://x402.devvizion.com/skill.md
- ACP hire path (machine): https://x402.devvizion.com/hire-path.json

## Alternate escrow channel (Virtuals ACP)

Buyers who hire agents via Virtuals: create-job on offering `019f8f2e-abd1-7ad6-a051-0ce709fdebcd` (`x402-research-brief` @ **0.05** USDC Base). Provider fulfills from this origin. Machine: `https://x402.devvizion.com/hire-path.json` · SPA: https://app.virtuals.io/acp/agents/019f8f2a-81d5-781c-af74-7aeee1909614

## One-liner

```text
First buy: free GET https://x402.devvizion.com/v0/sample-outline → unpaid POST /v0/outline → 402 → pay 0.01 USDC Base to 0xE79e7fa7Ce7259C46F9B127b837d2907Bb036F95 → retry X-PAYMENT. Full: https://x402.devvizion.com/buyer.md
```