Get started

Install

Install krino and its CLI, then add the host SDK you use: the Vercel AI SDK or the Claude Agent SDK. Needs Node 22 or later.

Requirements

Node 22 or later. krino is ESM only.
Node 22.18 or later to run a .ts file directly, as the quick starts do. On Node 22.6 to 22.17, run node --experimental-strip-types agent.ts instead.
A host SDK: the Vercel AI SDK or the Claude Agent SDK.

Install krino and the CLI

The library goes in your dependencies. The CLI reads traces, so it is a dev dependency.

Terminal

npm i @krinolabs/krino
npm i -D @krinolabs/cli

The CLI ships DuckDB's native binary to read traces. That binary never enters your app: the library is a separate package.

Add your host SDK

The host SDKs are optional peer dependencies. Install only the one you use. The Jev decision provider needs ai and zod on both hosts.

Host	Install	Tested with
Vercel AI SDK	`npm i ai zod`	`ai` 7.0.126 (supported range `>=7.0.111 <8`)
Claude Agent SDK	`npm i @anthropic-ai/claude-agent-sdk ai zod`	`@anthropic-ai/claude-agent-sdk` 0.3.286

Check your setup

Terminal

npx krino doctor

You should see one line per check: Node version, host SDK versions, your API key, the trace folder, and recent traces. Every warning comes with a fix line. A check with nothing to check yet shows SKIP.

Entry points

Import	What it holds	Needs
`@krinolabs/krino`	`createKrino`, the fake provider, the file trace sink, prices, and all types	nothing
`@krinolabs/krino/ai-sdk`	`withKrino`	`ai`
`@krinolabs/krino/claude-agent-sdk`	`krinoAgentOptions`, `observeKrinoMessages`	`@anthropic-ai/claude-agent-sdk`
`@krinolabs/krino/providers/jev`	`createJevAiGatewayProvider`	`ai`, `zod`

The root entry never imports a host SDK or ai.