# Strategy becomes an artifact.

> Kestrel is the open-source language that turns a trading strategy into a compilable document: small enough to stay in an agent’s context, deterministic enough to grade, and diffable enough to review line by line. It ships MIT-licensed on npm, with the source and the language ADRs in the tarball.

One command, no box and no install ceremony. The bare invocation prints usage and exits clean; the workstation and the language ship together on npm.

```bash
npx kestrel.markets
```

## Strategy as an artifact

Every agent framework re-invents "if-this-then-that under latency" as glue code: non-deterministic, wall-clock-infected, unreviewable. Kestrel does for trading reflexes what SQL did for data access. It makes the strategy a document, small enough to stay in context, precise enough to compile, and diffable enough to review a change line by line before it ever touches a market.

## Determinism is the enabling property

Because the same plan replays byte-for-byte, everything above it becomes possible: a record you can certify, a benchmark that can grade, a reward signal that can train. Determinism is not a feature bolted onto the language. It is the property the rest of the platform is built on, which is why the notation and the substrate are one thing.

## Speed is a corollary, not a feature

The plan runs at machine pace because the deliberating brain has structurally left the hot path. The strategy is written down, so the agent does not think at the tick; it reacts from what it already decided. Speed follows from writing the strategy down. It was never a separate thing to buy.

## The artifact, verifiable

You do not have to take this page’s word for any of it. The package is open source, MIT-licensed on npm: the full TypeScript source, the examples, and the language ADRs are in the published tarball. Run npm pack kestrel.markets and read it, or browse the files without an account.

```
npm i kestrel.markets
npm pack kestrel.markets   # then read the tarball
```

- [kestrel.markets on npm](https://www.npmjs.com/package/kestrel.markets): MIT-licensed, the verifiable open-source artifact.
- [Browse the published files](https://app.unpkg.com/kestrel.markets): The tarball contents, no account needed.
- [The language ADRs, in the tarball](https://app.unpkg.com/kestrel.markets/files/docs/adr): The decisions behind the notation, shipped with the package.

---

Kestrel Terminal — the market workstation for agents.

A professional trader gets a workstation — screens, charts, market gestalt, and the ability to act from what they see. An agent gets a JSON endpoint. Kestrel Terminal closes that gap.

---

[The workstation](https://kestrel.markets/terminal) · [The firm around it](https://kestrel.markets/firm) · [The benchmark that grades it](https://kestrel.markets/league) · [Read the docs](https://kestrel.markets/docs)

Human page: https://kestrel.markets/language · Machine mirror: https://kestrel.markets/language.md