How it works

Every operation follows the same shape, whether it arrives as an MCP tool call or an HTTP request: the service quotes a price, your client pays inline over x402, and the result comes back. No step requires an account or an API key.

Private preview

PDF As You Go is in private preview. Endpoints, retention windows, and supported networks may change. Access is granted on request — see Request preview access.

The flow at a glance

Agent / MCP client / HTTP client
        │  1. call a tool or POST an endpoint (document by URL or upload)
        ▼
┌─────────────────────────────────────────────┐
│  PDF As You Go service                        │
│                                               │
│  x402 middleware ── 2. 402 Payment Required   │
│        │            4. verify + settle        │
│        │               (via facilitator → chain)
│        ▼                                       │
│  Operation router (12 PDF ops)                │
│        │                                       │
│        ▼                                       │
│  PDF engine  ──►  5. result stored, signed URL │
└─────────────────────────────────────────────┘
        │  result URL + X-PAYMENT-RESPONSE
        ▼
        6. Agent downloads the output

Step by step

1. Request. Your client calls a tool (e.g. merge_pdfs) or hits an endpoint (e.g. POST /v1/merge) with the document and parameters. Documents are passed by URL or upload — not inline base64.

2. 402 Payment Required. If the request is unpaid, the server responds with HTTP 402 and a body describing exactly how to pay: the price ($0.05 in USDC base units), the network, the token contract, and the receiving address. See The 402 flow for the full body.

3. Sign. Your client builds a signed payment payload — a gasless authorization (EIP-3009 for USDC) — and retries the request with an X-PAYMENT header carrying the encoded payload. With an x402-aware client this is automatic; you never see it.

4. Verify & settle. A facilitator verifies the signature and settles the transfer onchain, so the service itself holds no blockchain infrastructure. Settlement is typically sub-2-second.

5. Run & store. On confirmed payment, the operation runs and the resulting PDF is stored behind a short-lived download URL.

6. Deliver. The server returns the result (a download URL, and optionally streamed bytes) plus an X-PAYMENT-RESPONSE header confirming settlement. Your agent downloads the output.

Note

One call = one operation = $0.05. A multi-step task — say merge, then watermark — is two operations, billed per call. See Operations & pricing.

What you don’t have to do

• No account. There is nothing to sign up for.
• No API key. There is no credential to issue, store, leak, or rotate — the payment authorization is the auth.
• No blockchain plumbing on your side beyond a funded wallet your client can sign with. The facilitator handles settlement.

Next

• Quickstart: MCP server
• Quickstart: HTTP API
• x402 payments — a deeper look at the payment protocol.