In my experience, the best approach to compaction is to never get to the point where you need compaction and to generally stay below about 30% context window utilization. Even for long agentic workflows this can be accomplished for quite a while, much longer than most people might think.

Here's what I do for each of my sessions:

1. For asides, off-topic work, or repetitive work that has already been done in the session, branch backwards (with /tree) and summarize.

2. If I've exceeded 30% or the 'price-doubling' multi-tier pricing, prune (my custom extension).

3. If I've already pruned and I'm still close to 30%, 'prune all' (more extensive prune).

Definition:

'/prune': Removes ~50% context on a fresh session (not previously pruned)

  - Keeps: User messages, normal assistant prose, commands/status markers, extension receipts, model settings, and a plain-text receipt for each tool call.
  - Removes: Thinking, signatures, actual tool calls/results, tool output, images, compaction summaries, and other extensions’ state.

'/prune-extended': Removes ~80% context on a fresh session

  - Keeps: User messages, normal assistant prose and conclusions, commands/status markers, extension receipts, and model settings.
  - Removes: Thinking, signatures, all tool calls/results and output, images, compaction summaries, other extensions’ state, and any tool-activity receipts created by /prune.

Both create a new session and delete the old one after a successful switch.

Using these I can keep a session going for weeks (or longer), even with extensive use and almost all the important context is preserved while dumping the less important context. Neither command requires an LLM summarization so they execute quickly.