> For the complete documentation index, see [llms.txt](https://docs.openbotauth.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbotauth.org/sdks/sdks.md).

# Overview

OpenBotAuth provides official SDKs for integrating signature verification directly into your applications. Both SDKs follow the same design principles:

* **No local cryptography** - All verification is delegated to the OpenBotAuth verifier service
* **Middleware support** - Drop-in middleware for popular frameworks
* **Observe mode** - Non-blocking verification for gradual rollout
* **Security-first** - Sensitive headers are never forwarded

## Available SDKs

| SDK                                     | Package                                                                                    | Frameworks                |
| --------------------------------------- | ------------------------------------------------------------------------------------------ | ------------------------- |
| [Node.js / TypeScript](/sdks/nodejs.md) | [@openbotauth/verifier-client](https://www.npmjs.com/package/@openbotauth/verifier-client) | Express, Next.js          |
| [Python](/sdks/python.md)               | [openbotauth-verifier](https://pypi.org/project/openbotauth-verifier/)                     | FastAPI, Flask, Starlette |

## When to Use SDKs

Use the SDK approach when:

* You want fine-grained control over verification logic
* You need to integrate with your existing authentication/authorization
* You want to make policy decisions in your application code
* You're building a Node.js or Python application

## Alternative: Proxy

If you prefer a zero-code approach or use a different language/framework, consider the [OpenBotAuth Proxy](/proxy/proxy.md) which sits in front of any HTTP backend.

## Core Concepts

### Verification Flow

```
1. Extract RFC 9421 signature headers from request
2. Send headers to verifier service
3. Receive verification result (verified, agent info, or error)
4. Make policy decision in your application
```

### Middleware Modes

Both SDKs support two middleware modes:

| Mode                | Behavior                                                           |
| ------------------- | ------------------------------------------------------------------ |
| `observe` (default) | All requests pass through; verification result attached to request |
| `require-verified`  | Protected paths return 401 if verification fails                   |

### Request State

After middleware processing, verification state is attached to the request:

```javascript
// Node.js
req.oba.signed    // boolean - request had signature headers
req.oba.result    // VerificationResult or null
```

```python
# Python
request.state.oba.signed    # bool - request had signature headers
request.state.oba.result    # VerificationResult or None
```


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.openbotauth.org/sdks/sdks.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.