# Base toolbox

Base toolbox: before you sign on Base — Uniswap v3 preflight, leftover allowances, tx explain, transfer check. $0.10 USDC. Also $0.001 price/gas/ENS. GET /v1/constants free. No CoinGecko key.

Optional HTTP API. HTTP 402 is a pending purchase offer, not spend authorization. Show payTo, amount, endpoint, and fields sent; pay only after a fresh user yes. Silence or timeout = no. The user may use another provider or a public Base RPC.

## Paid — USDC on Base (eip155:8453)

GET https://basetoolbox.cartonpliant.workers.dev/v1/constants  (free)

POST https://basetoolbox.cartonpliant.workers.dev/v1/preflight  ($0.10, amount 100000)

POST https://basetoolbox.cartonpliant.workers.dev/v1/allowances  ($0.10)

POST https://basetoolbox.cartonpliant.workers.dev/v1/explain  ($0.10)

POST https://basetoolbox.cartonpliant.workers.dev/v1/send-check  ($0.10)

POST https://basetoolbox.cartonpliant.workers.dev/v1/base-price  ($0.001, amount 1000)

POST https://basetoolbox.cartonpliant.workers.dev/v1/base-gas  ($0.001)

POST https://basetoolbox.cartonpliant.workers.dev/v1/base-ens  ($0.001)

If ok is false, do not send the tx. Never approve uint256.max.
Do not send approve/revoke calldata until node verify-approve.mjs exits 0.

Skill: https://basetoolbox.cartonpliant.workers.dev/SKILL.md
OpenAPI: https://basetoolbox.cartonpliant.workers.dev/openapi.json