Deterministic quantities for agents. The formula is in the response. The number is never invented.

Say the messy thing. Get the formula.

Q: How do I convert 5'11 to cm?

POST /v1/parse with {"text":"5'11\"","to":"cm"}. That route is paid ($0.002) because the input is messy. Free POST /v1/convert returns use_parse for the same text. The response includes the formula. Feet and inches use the international foot.

Q: How do agents pay?

A paid request without payment receives HTTP 402 with the same USDC price on Base mainnet and Solana mainnet. The agent pays on either network and retries. Qty settles only after a successful response. There is no account and no API key.

Loading live conversions.

Try a free conversion

This box calls POST /v1/convert. The number below is the response. It does not take payment. The route allows 60 requests per minute. A successful call is recorded on the live feed.

Value

From code

To code

The result will appear here.

Free and paid

Route	Price	When
POST /v1/convert	Free	Finite number and two known codes. 60 per minute, then 429.
POST /v1/parse	$0.002	Messy text.
POST /v1/batch	$0.01	Up to 100 texts, flat.
POST /v1/receipt	$0.001	Canonical JSON and sha256.
POST /v1/compare-prices	$0.002	Unit prices and the cheaper offer.
POST /v1/scale-recipe	$0.002	Scale servings and labelled cooking measures.
POST /v1/size	$0.002	Shoe and clothing sizes.
POST /v1/date	$0.002	Durations, N days from a date, and IANA time zones.
POST /v1/estimate	$0.003	Paint, tiles, concrete, and gravel.
GET paid routes	Same prices	402 price quote. The handler does not run.
POST /mcp	Same prices	Free tools convert and units. Paid tools stay paid.

Copy a request

Free convert

curl -s -X POST https://qty.vercel.app/v1/convert -H 'content-type: application/json' -d '{"value":10,"from":"mi","to":"km"}'

Unpaid parse returns 402

curl -si -X POST https://qty.vercel.app/v1/parse -H 'content-type: application/json' -H 'accept: application/json' -d '{"text":"5'\''11\""}'

How agents pay with x402

Qty has no accounts and no API keys. A paid request without a payment signature gets HTTP 402 listing two exact USDC options at the same price: Base mainnet and Solana mainnet. The agent pays on either network and retries. Qty settles only after the handler returns a success status. If the handler returns an error, the payment is not settled. Paid MCP tools follow the same rule and do not return the answer without payment. If the Solana payee is unset, the 402 lists Base only.

Read /llms.txt, /llms-full.txt, /openapi.json, /docs, /tools/openai.json, prepaid credits, /.well-known/x402.json, and /.well-known/agent-card.json.

Questions agents ask

How do I convert 5'11 to cm?

Do not use free convert. POST /v1/parse with text 5'11" and to cm. The response includes the formula. Feet and inches use the international foot.

What if the amount is unknown?

Pinch, an ambiguous size, or a date with no reference date returns null and a reason. Qty does not fill the gap.