pi-thinking-reformatter1.0.0

pi-thinking-reformatter

A Pi extension that reformats deepseek-style thinking blocks whose tokenization leaked stray line breaks, leading spaces, and spaces around punctuation, so they read like normal prose.

What it does

Some deepseek models (particularly flash thinking) emit reasoning where token boundaries bleed through as spurious whitespace. A typical broken block looks like this:

Ch
 rome-devtools
  is not
  connected
 .

This extension rewrites those blocks into normal prose:

Chrome-devtools is not connected.

It joins soft line breaks, re-attaches detached punctuation, and preserves paragraph breaks, fenced code blocks, lists, blockquotes and headers. A looksBroken heuristic leaves well-formed thinking blocks byte-for-byte unchanged, so reasoning from other models is never touched.

How it works

The live view is repaired through registerMarkdownTransformer, which re-runs on every streaming frame with the full thinking text. A full repair on every frame would be O(n) per token and re-reflow the whole block each time; a repair frozen between frames made the stream look choppy (the visible text stopped advancing, then jumped a batch at each boundary). Instead every frame appends the newly arrived raw tail to the last full repair, so the block grows token-by-token exactly like untransformed streaming, and a complete repair runs on a ~150ms time budget, bounding the CPU cost regardless of token rate. The tail region carries the stream's own artifacts for at most 150ms before the next full repair cleans it, and because the repair's rules are all local, that recompute only rewrites the tail - no whole-block reshuffle. On finalize the exact full repair is always recomputed. The message_end event then re-applies the same repair and returns a replacement message, so the repaired text is what actually gets stored in the session and what gets sent into model context on later turns - it is a durable fix, not just a display-time transformation.

Install

pi install npm:pi-thinking-reformatter

Or from git:

pi install git:github.com/mitchellnemitz/pi-thinking-reformatter

or from a local checkout:

pi install /path/to/pi-thinking-reformatter

Reload Pi (/reload) or restart it to load the extension.

Scope and limitations

• Fenced code blocks (```) are left byte-for-byte intact.
• Rare token splits that glue two lowercase fragments into a word (e.g. Ch\nrome-devtools) are not yet re-joined without a word dictionary; the dominant spurious-linebreak and punctuation-spacing cases are covered.
• Inline code spans are not fenced, so punctuation normalization can touch the inside of a backtick span in an already-broken block.
• Requires a Pi version that lets message_end handlers return a replacement message and exposes registerMarkdownTransformer.

Development

npm install
npm run typecheck