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

# SDKs

> Officially supported Node.js and Python SDKs for the chain layer

> Two officially supported SDKs at v1 launch. Both produce **byte-identical** cryptographic results against the same proof bundle — verified by cross-language parity tests in CI.

## Node.js / TypeScript

Package: [`@deepidv/chain`](https://www.npmjs.com/package/@deepidv/chain) on npm.

```bash theme={null}
npm install @deepidv/chain
```

```ts theme={null}
import { createClient, verifyBundle } from "@deepidv/chain";

// Read public registry data
const client = createClient({
  apiUrl: "https://api.deepidv.com",
});
const attestation = await client.getAttestation("att_01HZ8...");
console.log(attestation.envelope_hash);

// Verify a downloaded bundle
import { readFile } from "node:fs/promises";
const bundleBytes = await readFile("./attestation.dpiv");
const result = verifyBundle(bundleBytes);
if (result.ok) {
  console.log("Bundle verified.");
} else {
  console.error("Verification failed:", result.checks);
}
```

The Node SDK:

* Has **zero runtime dependencies** (uses `node:crypto` and global `fetch`)
* Ships as **dual ESM + CJS**
* Requires **Node 20+**
* **Skips RFC 3161 TSA verification** (returns `skipped`, not `verified`) — use `verify.sh` from the bundle for full TSA validation

## Python

Package: [`deepidv-chain`](https://pypi.org/project/deepidv-chain/) on PyPI.

```bash theme={null}
pip install deepidv-chain
```

```python theme={null}
from deepidv_chain import Client, verify_bundle

# Sync client
client = Client(api_url="https://api.deepidv.com")
attestation = client.get_attestation("att_01HZ8...")
print(attestation.envelope_hash)

# Verify a bundle
with open("./attestation.dpiv", "rb") as f:
    bundle_bytes = f.read()
result = verify_bundle(bundle_bytes)
if result.ok:
    print("Bundle verified.")
else:
    print(f"Verification failed: {result.checks}")
```

An async variant is also available:

```python theme={null}
from deepidv_chain import AsyncClient

async with AsyncClient(api_url="https://api.deepidv.com") as client:
    async for event in client.stream_attestations():
        print(event.attestation_id)
```

The Python SDK:

* Supports **Python 3.9 through 3.13**
* Sync and async clients with matching API surface
* **Pydantic v2** for wire-validated types
* Same TSA skip behavior as the Node SDK

## Cross-language parity

Every cryptographic primitive in both SDKs — JCS canonicalization, envelope hashing, STH hashing, manifest computation — is tested against pinned constants from shared fixtures. The Node SDK and Python SDK produce byte-identical outputs against the same envelopes, on every supported runtime version.