Images
- vision gate: text-only models get a note instead of image parts and no
view_image tool; unknown models retry once without images on HTTP 400
- paste: Ctrl+V and /attach paste read the clipboard (wl-paste, xclip,
pngpaste/osascript, Win32 PNG or CF_DIB converted to PNG); pasting image
file paths attaches them
- MCP image content is stored in the session and sent with the tool result
- attach: rel path validation, base64 decode, /retry keeps images
Model registry
- built-in src/models_builtin.json embedded at build time, merged with
<config>/models.json and cached GET /models metadata (context, vision,
pricing); most specific rule wins per field
- /model labels, /status source, --list-models [provider]
Cache and cost
- stable request prefix (frozen tools, notes as messages), DeepSeek prefix
completion, OpenAI/Anthropic cache hints, /cost and hit rate in the status
