---
title: "Getting started — KYE™ OSS"
description: "Install @kye/shadow-mode-sdk, register an observed action, generate an Evidence Pack, verify it offline. Pure local mode — no API key required."
url: https://kyeprotocol.com/oss/getting-started/
lang: en
source: "KYE Protocol"
---

> Install @kye/shadow-mode-sdk, register an observed action, generate an Evidence Pack, verify it offline. Pure local mode — no API key required.

# Getting started with KYE™ OSS

Install `@kye/shadow-mode-sdk`, register an observed action, generate an Evidence Pack, verify it offline. Pure local mode — no API key required.

[Get started →](https://kyeprotocol.com/oss/getting-started/) [Packages](https://kyeprotocol.com/oss/packages/)

[← OSS](https://kyeprotocol.com/oss/)

Plain Q&A

## Plain Q&A

Short questions. Short answers.

- **What is open?** Schemas, vocab, SDKs, verifier.
- **What is closed?** Nothing in the protocol layer.
- **Which licence?** Apache 2.0 for code. CC-BY-4.0 for vocab.
- **Where is the source?** On GitHub. KYE-Protocol org.
- **Can I fork?** Yes.
- **Can I contribute?** Yes. Open a PR.
- **Will you take my fix?** Yes if it follows the constitution.
- **Is the runtime open?** Reference Gateway is. Hardened build is paid.

Plain take

## Plain take

Apache 2.0 SDKs. CC-BY-4.0 vocab. No runtime lock-in.

- Three SDKs. One protocol. Same names.
- Schemas and vocab versioned on GitHub.
- Public JWKS. Open verifier.
- Bring your own runtime.

### Install the SDK

The SDK is published to npm under Apache 2.0.

npmbash

```
npm install @kye/shadow-mode-sdk

# or via pnpm / yarn / bun
pnpm add @kye/shadow-mode-sdk
yarn add @kye/shadow-mode-sdk
bun add @kye/shadow-mode-sdk
```

### Run in local-only mode (no cloud)

Local mode persists observed actions to a local JSON file. No network calls. Useful for offline development and CI.

example.tstypescript

```
import { ObservedActionBuilder, LocalSink } from "@kye/shadow-mode-sdk";

const sink = new LocalSink({ path: "./.kye-shadow.jsonl" });

const action = new ObservedActionBuilder()
  .actor("kye:agent:acme.ap_processor_007")
  .principal("kye:user:acme.cfo.j_okonkwo")
  .action("payment.propose")
  .target("VND-217:£4,820.00")
  .context({ amount_gbp: 4820 })
  .build();

await sink.write(action);
console.log("recorded", action.observed_action_id);
```

### Generate an Evidence Pack

The SDK's `buildEvidencePack()` assembles a CBOR pack from one or more observed actions and seals it with a local integrity tag for development use. (Production signing happens in the Cloud Gateway; the production construction is part of the patent track and is not disclosed here.)

example.ts (continued)typescript

```
import { buildEvidencePack } from "@kye/shadow-mode-sdk";

const pack = await buildEvidencePack({
  observed_actions: [action],
  tenant: "kye:tenant:acme.dev",
  signing_key: process.env.KYE_LOCAL_DEV_KEY,
});

await sink.writeEvidencePack(pack);
```

### Verify the pack offline

Use the Conformance Pack verifier CLI to verify the pack without contacting any KYE™ endpoint.

bashcli

```
npx @kye/conformance-pack-verifier verify ./pack.cbor \
  --keys ./trusted-keys.json

# Output:
#   ✓ pack_id          kye:ep:acme.dev:01HF...
#   ✓ schema_version   kye.evidence.evidence_pack.v1
#   ✓ signature        valid (key kid=kye:pk:acme.local.001)
#   ✓ hash_chain       continuous (1 action)
#   ✓ verdict          PASS
```

### Point at the Cloud Gateway (optional)

When you're ready to start ingesting into a real tenant, swap `LocalSink` for `KyeClient` with your gateway URL and tenant credentials. The builder and pack shapes are byte-identical.

example.ts (cloud)typescript

```
import { KyeClient } from "@kye/shadow-mode-sdk";

const client = new KyeClient({
  gatewayUrl: "https://gateway.kyeprotocol.com",
  tenant:     "kye:tenant:acme",
  apiKey:     process.env.KYE_API_KEY,
});

const decision = await client.ingest(action);
console.log(decision.decision, decision.evidence_pack_id);
```

### Next steps

• Read the [full package list](https://kyeprotocol.com/oss/packages/) for Python, the verifier CLI, and the widget protocol.
• Follow a [developer playbook](https://kyeprotocol.com/oss/playbooks/) to govern any agent, then scaffold a [starter template](https://kyeprotocol.com/oss/agent-dev-kit-templates/).
• Inspect the [interactive sandbox](https://oss.kyeprotocol.com/sandbox/) if you'd rather click than code.
• Already convinced? [Apply for a pilot →](https://oss.kyeprotocol.com/pilot-apply.html) to run KYE™ on your real agent traffic.

Canonical KYE™ surfaces referenced on this page: [Evidence Pack™](https://kyeprotocol.com/evidence-pack/) · [KYE™ Conformance Pack™](https://kyeprotocol.com/compliance/).