# AB-043: API Version Identified | AgentBadge

> Your API specification clearly states which version it is.

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 AB-043

 🔢

AB-043

# API Version Identified

 [📋 OpenAPI](https://agentbadge.xyz/rules#openapi)

 Pillar: Discovery

 Quick fix

 Severity: low

 Est. cost: $0

 Gap: documentation

 Fix: deterministic

## What it means

Your API specification clearly states which version it is.

## Why it matters

Version info lets agents handle changes gracefully. Without it, updates can break agent integrations silently.

## Evidence expected

This rule is verified by:

 http

 Source: Runtime probe

 ✗

### What's wrong

No version in the spec. Agents don't know if the API has changed.

 ✓

### What's right

Version is clearly identified, so agents can adapt to changes.

## Check this rule on your site

Enter your URL to check just this one rule (AB-001).

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## Related rules in OpenAPI

 [📋
 API Spec at Standard Location](https://agentbadge.xyz/rules/AB-039)
 [🛤️
 API Paths Defined](https://agentbadge.xyz/rules/AB-040)
 [🌐
 API Paths Reachable](https://agentbadge.xyz/rules/AB-041)
 [🔍
 Response Matches Spec](https://agentbadge.xyz/rules/AB-042)
 [🏷️
 API Title](https://agentbadge.xyz/rules/AB-044)

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## Machine-Readable

 This rule is also available as JSON:
 [/rules/AB-043.json](https://agentbadge.xyz/rules/AB-043.json)

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