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	@openbotauth/verifier-client	Express, Next.js
Python	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 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:

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

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