fix: resize images before sending to Anthropic API

[coleleavitt]

Summary

Fixes #12068

Images pasted from clipboard or read via the file read tool are sent to Anthropic's API without any size checks. Images exceeding 2000px in either dimension cause the API to reject the request.

Changes

• New packages/opencode/src/util/image.ts — processImage(buffer, mime) utility that progressively downsizes images using sharp:

  1. Try compression only (quality 80)
  2. Resize to fit within 2000px, preserving aspect ratio
  3. Reduce JPEG quality to 60
  4. Aggressive downscale to 1000px max
  • Gracefully degrades if sharp is not available (returns original image)
  • Target buffer size: ~3.75MB (under Anthropic's 5MB API limit)

• Modified packages/opencode/src/tool/read.ts — calls processImage() before creating base64 data URL for image files

• Modified packages/opencode/src/cli/cmd/tui/util/clipboard.ts — calls processImage() on all clipboard image paths (macOS, Windows, Linux wayland, Linux x11)

• Added sharp@0.34.5 as dependency in packages/opencode/package.json

Testing

• Typechecks pass across all 17 workspace packages
• Tested with 2560x1440 screenshots — correctly resized before API submission

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

I found one potentially related PR:

Related PR:

• PR feat: auto-compress clipboard images to avoid API size limits #6455 - "feat: auto-compress clipboard images to avoid API size limits" (feat: auto-compress clipboard images to avoid API size limits #6455)

This PR may be addressing the same or similar issue regarding image compression and API size limits for clipboard images. You should check if it's still open, abandoned, or if PR #12069 is meant to supersede it with a more comprehensive solution (including both clipboard and file read tool handling).

[coleleavitt]

Note: there's an earlier PR #6455 by @noah79 addressing the same clipboard image compression issue. That PR has a more feature-rich Image namespace with transparency detection and 23 unit tests, but it's been waiting on a rebase since Jan 12 and doesn't cover the file read tool path.

This PR covers both clipboard (clipboard.ts) and file read (read.ts) paths, uses a newer sharp version (0.34.5 vs 0.33.5), and has a simpler single-function approach with graceful degradation if sharp isn't available.

[lucasrueda]

@thdxr take a look at this please