# v0.25.7 — Fix Slack Image Processing Errors

## What Changed

**Image validation before injection** — Downloaded Slack images are now validated by checking magic bytes (JPEG, PNG, GIF, WebP, BMP, SVG), file size (must be between 100 bytes and 20MB), and detecting HTML error pages that Slack sometimes returns instead of actual images. Invalid files fall back to document handling instead of crashing sessions.

**Graceful error handling for unprocessable images** — The image injection instruction now includes fallback guidance so sessions handle "Could not process image" errors gracefully instead of entering a crash loop. This also prevents the issue from persisting across session rewinds since the instruction explicitly accounts for failure.

## What to Tell Your User

Images sent through Slack are now validated before the bot tries to process them. If an image is corrupted, too large, or in an unsupported format, the bot handles it gracefully instead of getting stuck in an error loop. This fixes the issue where certain images would cause repeated errors that persisted even after using the rewind feature.

## Summary of New Capabilities

| Capability | How to Use |
|-----------|-----------|
| Image validation | Automatic — bad images detected before they reach the session |
| Graceful image fallback | Automatic — unprocessable images handled without crash |
