Bug Description

When using opencode's default markdown rendering path (<code filetype="markdown">), URLs in AI responses are never emitted as proper OSC 8 hyperlinks. The terminal relies on its own URL auto-detection, which breaks when a long URL wraps across multiple terminal lines — Cmd/Ctrl+Click opens only a truncated URL.

Root Cause

The default rendering pipeline uses tree-sitter to highlight markdown content:

1. TextPart component renders <code filetype="markdown"> (see session/index.tsx)
2. CodeRenderable uses tree-sitter → produces SimpleHighlight[] tuples
3. treeSitterToTextChunks() converts highlights to TextChunk[], copying only visual styles (fg, bg, bold, italic, underline, dim) — never sets the link property
4. Theme scopes (markup.link, markup.link.url, string.special.url) in theme.tsx only define foreground color + underline
5. Without chunk.link, textBufferSetStyledText never calls linkAlloc(), no link_id is assigned, no OSC 8 sequences are emitted

In contrast, the experimental markdown renderer (OPENCODE_EXPERIMENTAL_MARKDOWN=true) correctly sets link: { url } on chunks, enabling proper OSC 8 hyperlinks.

Steps to Reproduce

1. Run opencode in a terminal that supports OSC 8 (e.g., iTerm2, Windows Terminal, Ghostty)
2. Ask the AI a question that produces a long URL in the response (e.g., a GitHub PR URL with comment anchor)
3. Let the URL wrap across terminal lines
4. Try to Cmd/Ctrl+Click the URL
5. Expected: Browser opens the full URL
6. Actual: Browser opens a truncated URL (only the portion on the clicked line)

Video Demonstration

Fix

The fix is in opentui (the rendering framework), not in opencode itself. A PR has been submitted to opentui that modifies treeSitterToTextChunks() to detect URL-bearing tree-sitter scopes (markup.link.url, string.special.url) and set the link property on those chunks, as well as on associated markup.link.label chunks.

Related opentui issues/PRs:

• Hyperlinks spanning wrapped lines are not grouped (missing 'id' parameter in OSC 8) opentui#735 — OSC 8 id parameter fix (experimental path)
• fix(renderer): add OSC 8 hyperlink id parameter and onChunks hook for link detection opentui#736 — PR for the id parameter fix
• anomalyco/opentui#(pending) — PR for tree-sitter link detection (this fix)

Environment

• opencode version: latest dev build
• Terminal: iTerm2, Ghostty (any OSC 8-capable terminal)
• OS: macOS (also affects Linux terminals with OSC 8 support)