# Apache Airflow 3.1.3 — Release & Upgrade Intelligence
- **Product:** Apache Airflow (https://airflow.apache.org)
- **Version:** 3.1.3
- **Released:** Nov 14, 2025
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/airflow/updates/3.1.3/

## Executive Summary (TL;DR)
Apache Airflow 3.1.3. Source highlight: 📦 PyPI: https://pypi.org/project/apache-airflow/3.1.3/

## New Features
- UI: Add resize functionality to DAG run and task instance notes (#57897) (#58068)
- Add Taiwan translation for UI (#58121)
- Add learning from Airflow 3 migration guide (#57989) (#58083)

## Bug Fixes
- **Client**: ``EnvironmentVariablesBackend`` → ``ExecutionAPISecretsBackend`` (routes to Execution API via SUPERVISOR_COMMS)
- **Server**: ``EnvironmentVariablesBackend`` → ``MetastoreBackend`` (direct database access)
- **Fallback**: ``EnvironmentVariablesBackend`` only (+ external backends from config like AWS Secrets Manager, Vault)
- Workers (supervisor + task runner) never use ``MetastoreBackend``, maintaining strict isolation
- External secrets backends (AWS Secrets Manager, Vault, etc.) work in all three contexts
- Supervisor falls back to Execution API client for connections not found in external backends