Accordion
GitHub
pi install npm:@a-fig/accordion

AccordionContext visualization & intelligent context management for coding agents

/compact

summarizes when full
0/ 100,000 budget

Accordion

folds block by block
0/ 100,000 budget

The context problem

Every coding agent runs on a limited context window. Most of it fills with things the agent doesn't need, and the signal drowns in the noise.

The promise

  1. 01

    No blocking calls for compaction

    /compact: agent waited 2 min 30 sAccordion: 0 s

  2. 02

    Longer, more useful sessions

    /compact: 0 of 598 old blocks recoverableAccordion: all 982 recoverable

  3. 03

    Cheaper inference

    Accordion: 84.9k tokens per call instead of the full 132.3k

pi install npm:@a-fig/accordion

A pi extension. MIT.

Context visualization

Accordion shows your agent's whole context window on one screen: one square per block, in conversation order.

Color → block type
  • User message
  • Thinking
  • Tool call
  • Tool result
  • Assistant response
Dice face → number of tokens in the block
Dull → folded

The thick box at the bottom is the protected tail: the newest ~20k tokens, which are never folded.

99,921 / 100,000

Hover a square to see what it is. Click one to fold it.

Every fold is reversible

A folded block collapses to a short digest, tagged with a unique code. Nothing is ever deleted; folding only changes what the agent is shown.

TOOL RESULT6.2k tokens

Read 240 lines from parser.ts: full source of the tokenizer, exports, and inline tests…

{#a3f2c9 FOLDED}

read → parser.ts, 240 lines · exports tokenize(), parse()

0.1k tokens

unfold("a3f2c9")
Brings the block back into the agent's context.
recall("a3f2c9")
Returns the full block once, as a tool result. The view doesn't change.

User messages and tool calls are never folded.

How the fold tag works

{#<code> FOLDED} <digest>

<code>
Six characters of base36, a hash of the block's id. The same block gets the same code in every session.
<digest>
A short summary whose shape depends on the block type: {#hs8v8v FOLDED} thought · ~154 tok · Alright, let's keep going. We just swept F5-F8 (all misses), credits at 45, 2 s… {#hi99jw FOLDED} F5-F8 all misses! 45 credits. Let me continue - **row G** (G1-G4 unknown): {#2jpyiu FOLDED} bash → 50 lines, ~308 tok · Waiting for your turn...
Who writes tags
Only Accordion. A digest you write yourself has no tag, so the agent can't undo your edit. 
function foldCode(id) {
  let h = 0x811c9dc5; // FNV-1a 32-bit
  for (let i = 0; i < id.length; i++) {
    h ^= id.charCodeAt(i);
    h = Math.imul(h, 0x01000193);
  }
  return (h >>> 0).toString(36).padStart(6, "0").slice(-6);
}

The conductor

Context management strategies. A conductor edits the context automatically, between the agent's turns.

  1. 01The agent takes a turn
  2. 02The conductor reads the context
  3. 03Folds & unfolds blocks(edits to context)

↺ repeats automatically

Strategies range from simple FIFO folding to harvesting attention from a 500M-parameter model to score each block's relevance.

Scores how relevant each block still is using attention from a 500M-parameter model, and compresses the least relevant first. Keeps the session under a hard budget.

The proof

Accordion's conductor outperforms naive compaction by 2.5× on SlopCodeBench, a long-horizon coding benchmark.

thermocline 5/6 checkpoints
compaction-naive 2/6

SlopCodeBench subset · DeepSeek V4 Pro · 100k-token budget · 1 run each

2nd place, best token compression · UC Berkeley AI Hackathon 2026

What's next for Accordion

  1. Develop, test, and ship better conductors

    Improve benchmark performance · Use data from recall for training · Research a perplexity-based conductor

  2. Make it easy for anyone to build conductors

    Conductor docs →

  3. Bring Accordion to more harnesses

    Vibe, OpenCode, Claude Code, Codex

    Today: pi

Your session, intact.

1 pi install npm:@a-fig/accordion

Restart pi if it's running.

2 /accordion

Run it inside pi. It prints a local URL; open it to see every live session.

Folding starts off. Turn it on when you're ready.