fast-dev-compaction

# fast-jev-compaction

Codex plugin that wraps session compaction with Jev decisions: before Codex
compacts, every tool call and result is scored in fast requests; after
compaction, the verbatim history Jev kept is re-injected as context. Also
usable as an npm library.

> [!WARNING]
> **I do not recommend using this.** This is an experimental proof of concept, not a
> tool I stand behind — for real work, just use the default compaction in Codex or
> Claude Code.
>
> The approach has been [critiqued in detail by Theo (@t3.gg)](https://x.com/theo/status/2100762304862384257),
> who argues that pruning tool calls and results on a probability threshold
> misunderstands how compaction and context management actually work: it discards the
> reasoning traces frontier models never expose over the API, ignores that models are
> trained on their own compaction flows, and makes history edits trigger expensive cache
> rewrites. Treat this repo as a write-up of an idea, not as something to run in a
> real workflow.

> **Codex port of [tamaratran/fast-jev-compaction](https://github.com/tamaratran/fast-jev-compaction).**
> The compaction engine (`src/`) and the Jev scoring design are by
> [@tamaratran](https://github.com/tamaratran); this repository replaces the
> original Claude Code function-hook adapter with Codex lifecycle hooks.

## What and why

Codex's built-in compaction asks a model to summarize old turns. A summary is
lossy: a file path, exact error, constraint, or command can disappear even
when it matters later. This plugin never rewrites anything. It only deletes
the tool calls and tool results Jev says are no longer needed, and it asks Jev
while showing it the whole conversation. User and assistant text stays
verbatim and in order.

The repository is both an npm package (