[CorticalCode]

Summary

Custom Command widgets receive context.data as JSON over stdin, but the terminal width was not part of it, so scripts had no way to adapt their output to the terminal. tput cols / stty size / $COLUMNS all report 80 in ccstatusline's piped stdio context, so the width is otherwise unrecoverable from a custom command. Requested in #308.

What changed

• src/ccstatusline.ts — populate terminalWidth once on the render context via getTerminalWidth(). Custom commands execute during preRenderAllWidgets, before renderStatusLine computes the width, so the value has to be on the context up front. As a side benefit, the renderer now reuses this value instead of re-probing per line.
• src/widgets/CustomCommand.tsx — add terminal_width to the JSON piped to the command when a numeric width is known (omitted otherwise).

{ "model": { "display_name": "..." }, "workspace": { "current_dir": "..." }, "terminal_width": 142 }

Notes

• Field name terminal_width (snake_case) matches the existing Claude Code payload (session_id, current_dir, used_percentage, …).
• Raw terminal width, not flex-adjusted — scripts get the actual column count (and it honors CCSTATUSLINE_WIDTH), independent of flexMode. This is complementary to feat(terminal): honor CCSTATUSLINE_WIDTH env var to override probe #380: CCSTATUSLINE_WIDTH overrides the probe, whereas this exposes the resulting width to custom-command stdin.
• Omitted when undetectable, so script authors can guard for its absence.

Use case

Adaptive labels — full text ("ReadCache", "CacheCreate") on wide terminals, abbreviated ("RC", "CC") on narrow ones — as described in the issue.

Testing

• New unit test (src/widgets/__tests__/CustomCommand.test.ts) mocking the execSync boundary: field present when width is known, existing data still passes through, field omitted when width is unknown.
• Full suite green (1396 tests), lint clean.
• Manually verified end-to-end with an adaptive custom-command script through both bun and the bundled dist (via node): full labels on wide terminals, abbreviated on narrow, the real tty width picked up with no override, and the raw width preserved under full-minus-40.
• docs/USAGE.md updated.

Closes #308

[sirmalloc]

Thanks, this will be published in the next release.