cputools FAQ

What is cputools?

A pay-per-call utility API for the CPU work your agent shouldn’t host itself. PDF tools are live today — merge, split, rotate, page edits, watermark, form fill/flatten, text extraction, and metadata. Your agent sends a file and a payment, gets a result back, and never created an account. The roster grows over time: QR & barcodes, OCR, render-to-image, and Office→PDF are next.

Do I need an account?

No. The lodestone path is one HTTPS call with an X-Payment header carrying an x402 (EIP-3009) authorization — no signup, no email, no deposit. The wallet that signs the payment is your identity, so your transaction history is there if you come back. If you’d rather fund from a prepaid balance, sign in via Google or GitHub and use a Bearer rs_live_* API key instead.

How does pricing work — will I get a surprise bill?

You won’t. Most PDF ops are $0.001 per page (extract-text $0.002, OCR $0.003, metadata $0.001 flat); CSV ops are $0.0002 per MB of input; image ops are $0.0003 per megapixel (metadata $0.0005 flat); QR and barcode are $0.0002 flat. Per-unit ops bill a minimum of one (one page / one MiB / one megapixel). There’s no subscription, no minimum, and no commitment — you pay only for the calls you make, debited from your Relaystation balance, and an unauthenticated POST returns the exact price for a call before you pay. When the balance hits zero, calls return a 402 response — no overdraft, no auto-charge.

How do I send a file bigger than 4 MB?

Inline base64 is capped at 4 MB (it travels in the JSON request body). For larger files, POST /v1/cputools/upload-url to mint a one-time, customer-scoped presigned upload; it returns { url, fields, inputKey, ... }. Upload the bytes with a multipart/form-data POST to url (send every fields entry plus a file part), then pass {"inputKey":"..."} as the file instead of {"inline":"..."}. Results above the threshold come back the same way — as a presigned outputUrl instead of inline base64.

What’s the egress surcharge?

A small per-MB charge ($0.0002/MB) that applies only when an output is delivered by storage reference — the large-file presigned-GET path. It covers the AWS egress cost on big outputs. Inline outputs (≤ 4 MB, returned through the API) don’t incur it. It’s the only place cputools meters by size rather than by page.

Can I call cputools over MCP?

Yes. The full cputools catalog — 24 tools (the 23 ops plus cputools_upload_url) — is callable over MCP at https://api.relaystation.ai/mcp, the same endpoint that carries Relaystation’s Courier and chassis tools, all funded from one balance with one key. Drop the URL into Claude Code/Desktop, Cursor, Codex, Cline, Continue, or Cowork with a Bearer rs_live_* key. See the MCP tools page for per-client config.

What are the tools built on?

Open-source pdf-lib (manipulation) and pdf.js (text extraction) — pure JavaScript, no native binaries. These are tools you could self-host; cputools just runs them so you don’t have to maintain the infrastructure, the Lambda layers, or the cold-start tax.

How does cputools relate to the rest of Relaystation?

It’s one product on the Relaystation chassis. One balance funds cputools, Courier, Baton, and every other Relaystation product — top up once via x402, Stripe, or a crypto wallet, and spend it anywhere. Same wallet-as-identity, same transparent ledger, same pay-per-call promise — no subscription, no minimum. Relaystation docs →

Is my file content private?

cputools is stateless: a file goes in, a result comes out, and scratch objects for the large-file path are short-lived and customer-scoped. We don’t retain your documents to train anything or scan their contents for upsell targeting — that’s forbidden regardless of revenue payoff, the same privacy stance as the rest of the Relaystation family.