callcheck

The tool call reliability layer.

Validates AI tool call responses against a schema and auto repairs the ones that fail, before your agent acts on them.

npm install callcheck

→ Zod based schema validation, no new schema language to learn → Auto repair failing responses using any model → Wrap a tool once, every call after is protected → Free repair calls through Vercel AI Gateway, no separate subscription → Framework agnostic, works with any AI provider → Local failure tracking, see which fields and models break most

Usage

callcheck check --schema schema.json --response response.json
callcheck check --schema schema.json --response response.json --repair
callcheck report

import { validated, gatewayRetry } from "callcheck";

const tool = validated(myTool, {
  repair: true,
  retry: gatewayRetry(process.env.AI_GATEWAY_API_KEY),
});

Repo layout

packages/callcheck   the npm package and CLI
apps/web             landing page and docs, callcheck.abhivarde.in

Docs

Full usage docs at callcheck.abhivarde.in/docs

License

MIT