> ## Documentation Index
> Fetch the complete documentation index at: https://docs.echozero.app/llms.txt
> Use this file to discover all available pages before exploring further.

# SDK client libraries

> Official TypeScript, Python, Go, and Rust packages for REST, WebSocket, and webhook signing.

<Note>
  **Coming soon:** Packages are not yet published to npm, PyPI, or crates.io. This page documents the finished SDK spec. Use the REST API and [signature test vectors](/guides/signature-test-vectors) until packages ship.
</Note>

The [echozero-sdk](https://github.com/EchoZeroApp/echozero-sdk) repo provides clients in **four languages**: TypeScript, Python, Go, and Rust.

## Install (when published)

```bash theme={null}
npm install @echozero/sdk
```

```bash theme={null}
pip install echozero
```

```bash theme={null}
go get github.com/EchoZeroApp/echozero-sdk/packages/go/echozero
```

```toml theme={null}
# Cargo.toml
echozero = { git = "https://github.com/EchoZeroApp/echozero-sdk", package = "echozero" }
```

## REST client

```typescript theme={null}
import { EchoZeroClient } from '@echozero/sdk';

const client = new EchoZeroClient({
  apiKey: process.env.EZ_API_KEY!,
  hmacSecretKey: process.env.EZ_SECRET_KEY,
});

const me = await client.get('/api/v1/users/me', { hmac: true });
```

```python theme={null}
from echozero import EchoZeroClient

client = EchoZeroClient(api_key="ez_live_...", hmac_secret_key="ezs_...")
me = client.get("/api/v1/users/me", hmac=True)
```

## Inbound webhook signing

```typescript theme={null}
import { signInboundWebhook } from '@echozero/sdk';

const headers = await signInboundWebhook({
  signingSecret: process.env.EZW_SECRET!,
  body: { text: 'BUY SOL $100', idempotencyKey: 'key-1' },
});
```

## WebSocket signal client

Connect to `wss://mcp.echozero.app/ws/signals` with `x-api-key` in the Socket.IO handshake. Emit `signal` events with the same JSON schema as the inbound webhook.

## Verify outbound webhooks

SDK helpers implement `verifyInboundWebhook` and outbound `signal.execution` verification. Golden vectors are in [Signature test vectors](/guides/signature-test-vectors).