name	side-compact
description	Summarise the CURRENT Claude Code session with a cheaper model (Sonnet 5 by default) and write it to a file, so you can start a fresh session seeded from it. A cheap, model-configurable alternative to /compact. Use when the user wants to compact, summarise, or hand off this conversation cheaply, or asks to "compact with a cheaper model".
allowed-tools	Bash

side-compact

Summarise the session this skill is running in, using a cheaper model, and write the summary to a file. Native /compact always runs on the main session model; this runs the summarisation on a model the user chooses.

How it works

The running session's transcript is identified by the CLAUDE_CODE_SESSION_ID environment variable, which summarise_session.py reads automatically. Do NOT guess the transcript or pick the "latest" file: the script resolves the exact JSONL for this thread from that variable. It then renders the transcript to plain text, prefixes each turn with a [L<n>] marker pointing back to the source JSONL line, and summarises it with claude -p, fully isolated (--tools "", a summariser-only system prompt, a throwaway working directory) so the summarisation call cannot load a project's CLAUDE.md or act on the transcript.

The written summary opens with a header naming the source JSONL and a ## Chapters table of contents. Each chapter cites a (lines X-Y) range in that JSONL, so a fresh session that wants more detail than the prose gives can Read the transcript at those offsets directly.

Steps

Run the script. It auto-targets this session and prints the summary path:
```
python3 ~/.claude/scripts/summarise_session.py \
  --detail detailed \
  --out-dir ~/.claude/session-summaries
```
- Default model is sonnet (the alias resolves to Sonnet 5). If the user named a cheaper/different model, pass --model <model> (e.g. --model haiku).
- For a shorter summary, pass --detail brief.
- Run it verbatim with no other flags: --cwd and the session id default correctly inside a live session.
Tell the user the summary path that was printed.
Explain the next step: a skill runs inside the session and cannot clear or relaunch it. To actually free up context, the user starts a fresh session seeded from the summary, e.g.
```
claude "Read the session summary at <path> and continue from where it leaves off."
```
or run side-compact in their terminal, which does this in one step.

Notes

If the script reports no transcript, CLAUDE_CODE_SESSION_ID was not set (e.g. invoked outside a normal session); fall back to --transcript <path>.
Do not paste the summary contents into the conversation unless asked; the point is to keep this session's context small.

side-compact

How it works

Steps

Run the script. It auto-targets this session and prints the summary path:

python3 ~/.claude/scripts/summarise_session.py \
  --detail detailed \
  --out-dir ~/.claude/session-summaries

Default model is sonnet (the alias resolves to Sonnet 5). If the user named a cheaper/different model, pass --model <model> (e.g. --model haiku).
For a shorter summary, pass --detail brief.
Run it verbatim with no other flags: --cwd and the session id default correctly inside a live session.

Tell the user the summary path that was printed.

Explain the next step: a skill runs inside the session and cannot clear or relaunch it. To actually free up context, the user starts a fresh session seeded from the summary, e.g.

claude "Read the session summary at <path> and continue from where it leaves off."

or run side-compact in their terminal, which does this in one step.

Notes

If the script reports no transcript, CLAUDE_CODE_SESSION_ID was not set (e.g. invoked outside a normal session); fall back to --transcript <path>.

Do not paste the summary contents into the conversation unless asked; the point is to keep this session's context small.