A paid API you can pay for right now.

This is Tollstile running on Cloudflare Workers with its SQLite ledger on D1. Every call below answers 402 with a signed quote, takes payment, settles, and writes the charge to the ledger you can watch at the bottom. The rail is the test rail, so paying costs nothing: send Payment: test quote=….

Try it from this page

Or from your terminal

# 402 Payment Required, with a signed quote
curl -i https://demo.tollstile.com/v1/forecast?city=Osaka

# pay it (the test rail takes "test quote=<quote>")
curl -i -H "Payment: test quote=<quote>" "https://demo.tollstile.com/v1/forecast?city=Osaka"

# a price computed from the body — the quote is bound to that exact body
curl -i -X POST --data "the weather in tokyo is clear" https://demo.tollstile.com/v1/translate

Or from an agent, over MCP

Streamable HTTP at https://demo.tollstile.com/mcp. Call pricing free, then forecast for $0.01 by putting the payment in _meta. summarize costs up to $0.50 and is never charged silently: the server asks the person at the client to approve it, and a call they decline is released.

claude mcp add --transport http tollstile-demo https://demo.tollstile.com/mcp

Most clients do not let a model write _meta, so paying is the client's job, not the model's. This agent shows both halves: it holds a budget it will not spend past, and it answers the approval request the server sends back.

The ledger, live

Charges written by every call above — yours and everyone else's. Refreshes every two seconds.

Source: examples/demo · Docs: tollstile.com/docs · Prices here are play money; nothing is charged to anyone.