prune-context

name	prune-context
description	Selectively prune redundant lines from .agent/FULL_CONTEXT.md via AI (Gemini/Codex). Use when FULL_CONTEXT.md has grown large (500+ lines). Distinct from /compact (Claude Code built-in, which summarizes the live conversation).
disable-model-invocation	true
allowed-tools	Read, Write, Edit, Glob

Prune FULL_CONTEXT.md (selective line removal)

Not to be confused with /compact. /compact is Claude Code's built-in conversation summarizer. /prune-context removes redundant lines from the durable .agent/FULL_CONTEXT.md log. See the "Which compaction do I need?" table in CLAUDE.md.

Use Gemini (or the standard fallback chain) to surgically remove redundant lines from .agent/FULL_CONTEXT.md while preserving all important context.

Prerequisites

• At least one backend must be available. Try in order: Gemini MCP → $GEMINI_API_KEY curl → Codex MCP → Claude subagent (last resort)
• FULL_CONTEXT.md should be large enough to warrant compaction (500+ lines)
• The Claude subagent has a 200K token window — for very large logs, it may need to process in chunks

Steps

1. Check size. Read .agent/FULL_CONTEXT.md and count lines. If under 500 lines, tell the user it's not worth compacting yet and stop.

2. Archive the original. Copy the current file:

   cp .agent/FULL_CONTEXT.md .agent/LOGS/FULL_CONTEXT.pre-compact.md
   

3. Send to the backend (using the standard fallback chain) with this prompt:

   Read this entire context log. Identify lines that are redundant, superseded by later entries, or no longer relevant.

   Output ONLY the line numbers to remove, grouped by reason.

   Preserve: all decisions, all open task references, all lessons learned, all architectural context. Remove: duplicate status updates, resolved issue descriptions, stale progress notes.

4. Remove only the identified lines. Use the Edit tool to remove each group of lines the backend identified. Work in reverse order (highest line numbers first) to avoid offset drift.

5. Append a compaction note at the end of FULL_CONTEXT.md:

   --- Compacted on YYYY-MM-DD: removed N lines (Gemini-selected) ---
   

6. Report results to the user: how many lines before, how many removed, how many remain.

Rules

• This is a rare operation. Most projects will never need it.
• NEVER compact without an AI backend — human judgment is too lossy. Use the standard fallback chain.
• NEVER delete the archive until the user confirms the compaction looks good.
• If in doubt about whether to remove a line, keep it.