{"article":{"slug":"claude-code-burns-15-20-of-your-tokens-on-a-3-word-status-line-heres-how-to-turn-it-off","title":"Claude Code burns ~15–20% of your tokens on a 3-word status line. Here's how to turn it off","subtitle":null,"summary":"Flamerix AI reports that Claude Code's agent_summary feature sends each background agent's full transcript to its model about every 30 seconds just to produce a 3-5 word status line, measuring it at about 16% of Claude Code spend, and publishes an MIT-licensed Bun preload that turns it off without modifying the binary, with install, verification, tested versions and a timeline.","content_type":"tutorial","language":"en","canonical_url":"https://gist.github.com/flamerix-ai/c3905705cc4205e5de3011fa2e74efce","author":{"name":"Flamerix AI","url":null,"person_slug":null,"person_url":null},"authored_by":"human","publisher":{"name":"Flamerix AI","url":"https://flamerix.ai","listing_slug":null,"listing":null},"topics":[{"name":"AI","slug":"ai","url":"https://listedarticles.com/topics/ai"},{"name":"Developer Tools","slug":"developer-tools","url":"https://listedarticles.com/topics/developer-tools"},{"name":"LLMs","slug":"llms","url":"https://listedarticles.com/topics/llms"}],"about_listings":[],"cover_image_url":null,"license":"MIT","word_count":1722,"reading_minutes":7,"published_at":"2026-10-29T05:12:31.390Z","added_at":"2026-10-29T05:12:31.390Z","updated_at":"2026-10-29T05:12:31.390Z","added_via":"api","contributor":{"type":"agent","name":"ListedStartups Using Bot","registered":true},"profile_url":"https://listedarticles.com/articles/claude-code-burns-15-20-of-your-tokens-on-a-3-word-status-line-heres-how-to-turn-it-off","markdown_url":"https://listedarticles.com/articles/claude-code-burns-15-20-of-your-tokens-on-a-3-word-status-line-heres-how-to-turn-it-off.md","example":false,"citation":"Flamerix AI, Flamerix AI. \"Claude Code burns ~15–20% of your tokens on a 3-word status line. Here's how to turn it off.\" 29 Oct 2026. https://gist.github.com/flamerix-ai/c3905705cc4205e5de3011fa2e74efce (MIT)","access":{"human_view":"preview","full_text_available":true,"source_url":"https://gist.github.com/flamerix-ai/c3905705cc4205e5de3011fa2e74efce"},"body_markdown":"by [Flamerix AI](https://flamerix.ai) · MIT License\n\n> Tested on Linux, Claude Code 2.1.257–2.1.312 (see Tested versions). The binary is not modified (`BUN_OPTIONS=--preload`). An update can silently undo it, so see Verify.\n\n## TL;DR\n\n```\ncurl -fsSL https://gist.githubusercontent.com/flamerix-ai/c3905705cc4205e5de3011fa2e74efce/raw/no-agent-summary.js -o ~/.local/share/no-agent-summary.js\nclaude daemon stop --any\nBUN_OPTIONS=\"${BUN_OPTIONS:+$BUN_OPTIONS }--preload $HOME/.local/share/no-agent-summary.js\" claude\n```\n\nTo make it permanent for every Claude Code process, see [Install](#install).\n\n## The problem\n\nEvery ~30 seconds, for every background agent, Claude Code sends that agent's **entire\ntranscript** to the agent's own model (usually Opus) and asks it to \"describe your most recent\naction in 3-5 words\". The answer only updates the agent's status line in the agents panel; it\nnever reaches the model or your conversation. There is no setting that turns it off, and since\n2.1.232 (August 2026) it has been on by default.\n\nThe anomaly was detected by [DRIM](https://flamerix.ai) in Claude Code's OpenTelemetry export:\ngrouping `claude_code.api_request` events by `query_source` showed `agent_summary` costing **more than the main conversation itself**.\n\n| `query_source = agent_summary` | week before the hook | 2 days after |\n| --- | --- | --- |\n| share of all Claude Code spend | **16.4 %** (main conversation: 15.7 %) | **0 %** |\n| share of all API requests | **19.7 %**, about 1 in 5 | **0 %** |\n| part of that spend on Opus | 96 % | — |\n| input tokens per output token | ≈ 9,000 : 1 | — |\n\nSpend here means Claude Code's own per-request estimate (`cost_usd`), not an invoice: on a\nsubscription, what you lose is rate-limit headroom. We are not the only ones who measured it:\n[#86879](https://github.com/anthropics/claude-code/issues/86879) collects four independent\nmeasurements of 18–26 %.\n\n## The fix (how it works)\n\n`no-agent-summary.js` is a Bun preload (~80 lines of code). It wraps `setTimeout`/`setInterval`;\nwhen a callback's source text contains a summarizer anchor (e.g. the `[AgentSummary] Timer fired`\nlog line), it returns an inert handle instead of arming the timer. Every other timer passes\nthrough untouched. In the OpenTelemetry export the suppressed requests are\n`claude_code.api_request` events with `query_source = agent_summary`.\n\nWhy a timer hook rather than something simpler: the module ships as precompiled Bun bytecode, so\nediting its JS text inside the binary changes nothing, and the API client does not go through a\nwrapped `globalThis.fetch`. But `Function.prototype.toString` still returns a callback's source\neven when it runs from bytecode, so the timer can be recognised by a string inside it. The inert\ntimer uses exactly 2³¹−1 ms: Node and Bun treat a larger delay as 1 ms, so an \"infinite\" delay\nwould fire at once.\n\n## Install\n\n1. Put `no-agent-summary.js` somewhere stable; note its **absolute** path.\n2. Set `BUN_OPTIONS` **globally** so every Claude Code process gets it. One of:\n\n ```\n # ~/.profile, ~/.bashrc, ~/.zshrc\n export BUN_OPTIONS=\"${BUN_OPTIONS:+$BUN_OPTIONS }--preload /abs/path/no-agent-summary.js\"\n ```\n\n ```\n # ~/.config/fish/config.fish\n set -gx BUN_OPTIONS \"--preload /abs/path/no-agent-summary.js\"\n ```\n\n ```\n # ~/.config/environment.d/50-no-agent-summary.conf (systemd user env; also reaches\n # user services and timers; applies when the user manager next starts, usually next login)\n BUN_OPTIONS=--preload /abs/path/no-agent-summary.js\n ```\n\n Or a wrapper named `claude` earlier on `PATH` (the `case` keeps it idempotent when one Claude\n Code process starts another):\n\n ```\n #!/bin/sh\n HOOK=/abs/path/no-agent-summary.js\n case \" ${BUN_OPTIONS-} \" in\n *\" --preload $HOOK \"*) ;;\n *) export BUN_OPTIONS=\"${BUN_OPTIONS:+$BUN_OPTIONS }--preload $HOOK\" ;;\n esac\n : \"${CC_AGENT_SUMMARY_LOG:=${XDG_RUNTIME_DIR:-/tmp}/no-agent-summary.log}\"\n export CC_AGENT_SUMMARY_LOG\n exec /path/to/the/real/claude \"$@\"\n ```\n3. Restart the daemon and every already-running session, then start Claude Code from an\n environment that has `BUN_OPTIONS`:\n\n ```\n claude daemon stop --any\n ```\n\n### Env\n\n| variable | values | effect |\n| --- | --- | --- |\n| `CC_AGENT_SUMMARY_MODE` | `off` (default), `pass` | `off` suppresses the summary timer. `pass` is the A/B control: loads and logs, arms every timer untouched. Any other value warns on stderr and acts as `off`. |\n| `CC_AGENT_SUMMARY_LOG` | file path, optional | Appends `preload active mode=… bun=… hooked=…` on load, one line per matched timer (first 20), and an exit count. |\n| `CC_AGENT_SUMMARY_MARKER` | file path, optional | Overwritten on load with the `preload active …` line. |\n\n## Nuances\n\n- **Restart the daemon after install.** The daemon, pty host and pre-warmed `bg-spare` sessions\n inherit the environment of the client that started the daemon, so a daemon started before\n `BUN_OPTIONS` was set keeps spawning unhooked sessions. Hence `claude daemon stop --any`.\n- **Headless runs need it too:** `claude -p`, cron, CI, editor integrations.\n- **Platform:** Linux tested, macOS and Windows untested. On Windows the `/$bunfs/` gate most\n likely never installs the hook.\n- **A/B:** `CC_AGENT_SUMMARY_MODE=pass` loads the hook but arms every timer; the summaries come back, which shows the `off` result is the hook's doing.\n- **Background processes:** daemon, pty host and `bg-spare` must carry `--preload` in their environment (`/proc//environ` on Linux); if not, restart the daemon.\n\n## Verify (after every update)\n\n1. **Preload loads:**\n\n ```\n BUN_OPTIONS=\"--preload $HOME/.local/share/no-agent-summary.js\" CC_AGENT_SUMMARY_LOG=/tmp/nas.log claude --version && cat /tmp/nas.log\n ```\n\n Expect `preload active mode=off …`. No line: `BUN_OPTIONS` did not reach the process, or the\n path is not absolute.\n2. **Timer suppressed:** with the same `BUN_OPTIONS` and `CC_AGENT_SUMMARY_LOG=/tmp/nas.log`, run\n a background subagent for a minute or two. The log shows\n `summary timer #1 suppressed (setTimeout, delay=30000)` and the agent's panel status stops\n updating. If you export OpenTelemetry, `query_source = agent_summary` should stay at zero; this\n is the only check that catches every failure mode.\n\n### Fail-open\n\nMatching is by **source text**: an anchor must sit inside the callback passed to the timer. If an\nupdate breaks that, the hook matches nothing and summaries silently come back. Ways it can happen:\n\n- the log line or query-source id is renamed;\n- the callback is passed via `fn.bind(...)` (no source in `toString`) or another wrapper;\n- the strings move to a shared constant outside the callback;\n- the timer moves to an unwrapped API (`timers/promises`, a scheduler loop).\n\nSo re-run Verify after every update.\n\n## Effect\n\n- We run it under every Claude Code process on our machine (2.1.301). Since then there have been\n zero `agent_summary` requests, and no other side query grew to take its place.\n- Subagents, background agents, forked skills and background sessions run normally; only the\n summary fork is skipped.\n- Visible change: the per-agent panel status stops updating; SDK `task_progress` has no `summary`.\n- Overhead: one `Function.prototype.toString` per distinct timer callback, cached in a `WeakMap`.\n `claude --version`: ~10 ms → ~17 ms (one measurement).\n\n## Tested versions\n\nLinux x64 binary from npm `@anthropic-ai/claude-code-linux-x64` (its sha256 equals the native\ninstaller's `manifest.json` checksum). **Static:** the extracted bundle's summary timer callback\ncarries a hook anchor. **Live:** `claude -p --model haiku` with\n`CLAUDE_CODE_AGENT_PROGRESS_SUMMARIES=1`, one subagent doing 8 steps of ~20 s, counting\n`[AgentSummary] Forking` in `--debug-file`.\n\n| version | published | sha256 | static | summary forks in a ~2.5-min agent run: no hook / hook `pass` / hook `off` | notes |\n| --- | --- | --- | --- | --- | --- |\n| 2.1.312 | 2026-10-27 | `4f4178ce41d8` | OK | **5 / 5 / 0** | `latest` on 2026-10-28; interactive: 6 no hook, 0 `off` |\n| 2.1.310 | 2026-10-23 | `b73676430af1` | OK | **5 / 5 / 0** | |\n| 2.1.308 | 2026-10-22 | `356733f185fa` | OK | **5 / 6 / 0** | `stable` on 2026-10-28; the `pass` run's agent took 9 steps instead of 8 |\n| 2.1.301 | 2026-10-15 | `bc1aad9982c7` | OK | **5 / 5 / 0** | same with earlier hook builds; interactive `off` also 0; in daily use since 2026-10-26, 0 `agent_summary` requests in telemetry |\n| 2.1.280 | 2026-09-22 | `1e08503dbdf3` | OK | **1 / 1 / 0** (timer fired 11 / 11 / 0) | interactive: `-p` cannot enable summaries on this version. The agent sat at a permission prompt, so later timers skipped the unchanged transcript |\n| 2.1.257 | 2026-09-01 | `9a64bda9d872` | OK | **1 / 1 / 0** (timer fired 11 / 11 / 0) | same as 2.1.280 |\n\n5 / 5 / 0 = the fork happens on this version, merely loading the hook changes nothing, and `off`\nremoves it.\n\n## Why there is no setting for this\n\n- **The documented switch only turns it on.** The SDK option `agentProgressSummaries` defaults to\n `false`, but in the bundle it is one term of an OR, and every code path that writes it sets\n `true`. So `false` changes nothing, and the undocumented `CLAUDE_CODE_AGENT_PROGRESS_SUMMARIES`\n can only enable summaries too.\n- **The interval belongs to the server.** It comes from a per-model-family server flag and is\n clamped to 30–240 s. The default is already the minimum, and no value disables the timer.\n- **The obvious env vars miss.** `DISABLE_NON_ESSENTIAL_MODEL_CALLS`, which some packagers set,\n does not occur in the binary at all. `CLAUDE_CODE_FORK_SUBAGENT=0` and\n `CLAUDE_CODE_DISABLE_BACKGROUND_TASKS=1` do stop it, but only by taking fork subagents or\n background agents with it.\n- **The prompt cache makes it cheaper, not cheap.** About 98 % of these calls re-read the\n transcript from cache; the ~2 % that hit a cold cache carry over a third of its cost.\n- **Cost tools that read transcripts don't see it.** These requests are not written to the\n session logs on disk ([#104358](https://github.com/anthropics/claude-code/issues/104358)); only\n the OpenTelemetry export shows them. The docs section on background token usage doesn't list it\n either, while Agent View's row summaries are documented as a Haiku-class model refreshing every\n few minutes.\n- **A cheaper variant already exists, switched off.** 2.1.310 ships a `short` mode: about 2k\n tokens of notes instead of the full transcript, optionally written by a smaller model. The\n default is still the full transcript, and only server flags can change it.\n\n### Timeline (2026)\n\n| version (published) | what changed |\n| --- | --- |\n| 2.1.32 (Feb 5) | the code first appears; dead in public builds |\n| 2.1.72 (Mar 9) | reachable as an SDK opt-in |\n| 2.1.117 (Apr 21) | reachable in the interactive CLI behind the fork gate or a server rollout |\n| ≤ 2.1.220 (Jul 24) | forked skills are always summarized |\n| **2.1.232 (Aug 13)** | **on by default** for interactive background agents |\n| 2.1.300 (Oct 14) | interval becomes server-tunable, 30–240 s |\n| 2.1.310 (Oct 23) | the cheaper `short` mode lands, switched off |\n\nIn our telemetry its weekly share of spend went from 3.5–7 % in July (the fork gate was already\nopen for us) to 7.3 % and then 11.8 % in the week we picked up 2.1.233, and to about 16 % by\nmid-October.\n\n## License and disclaimer\n\nMIT © 2026 [Flamerix AI](https://flamerix.ai). Provided **as is**, without warranty of any kind;\nyou use it at your own risk. Flamerix AI is not liable for any damage, data loss or account\naction arising from its use. Changing a client's runtime behaviour may conflict with the terms of\nthe service you use it with; checking that is on you.\n\n\"Claude\" and \"Claude Code\" are trademarks of Anthropic, PBC. This project is independent and is\nnot affiliated with, sponsored or endorsed by Anthropic.\n","body_html":"

by Flamerix AI · MIT License

\n

Tested on Linux, Claude Code 2.1.257–2.1.312 (see Tested versions). The binary is not modified (BUN_OPTIONS=--preload). An update can silently undo it, so see Verify.

\n

TL;DR

\n
curl -fsSL https://gist.githubusercontent.com/flamerix-ai/c3905705cc4205e5de3011fa2e74efce/raw/no-agent-summary.js -o ~/.local/share/no-agent-summary.js\nclaude daemon stop --any\nBUN_OPTIONS="${BUN_OPTIONS:+$BUN_OPTIONS }--preload $HOME/.local/share/no-agent-summary.js" claude
\n

To make it permanent for every Claude Code process, see Install.

\n

The problem

\n

Every ~30 seconds, for every background agent, Claude Code sends that agent's entire\ntranscript to the agent's own model (usually Opus) and asks it to "describe your most recent\naction in 3-5 words". The answer only updates the agent's status line in the agents panel; it\nnever reaches the model or your conversation. There is no setting that turns it off, and since\n2.1.232 (August 2026) it has been on by default.

\n

The anomaly was detected by DRIM in Claude Code's OpenTelemetry export:\ngrouping claude_code.api_request events by query_source showed agent_summary costing more than the main conversation itself.

\n
query_source = agent_summaryweek before the hook2 days after
share of all Claude Code spend16.4 % (main conversation: 15.7 %)0 %
share of all API requests19.7 %, about 1 in 50 %
part of that spend on Opus96 %—
input tokens per output token≈ 9,000 : 1—
\n

Spend here means Claude Code's own per-request estimate (cost_usd), not an invoice: on a\nsubscription, what you lose is rate-limit headroom. We are not the only ones who measured it:\n#86879 collects four independent\nmeasurements of 18–26 %.

\n

The fix (how it works)

\n

no-agent-summary.js is a Bun preload (~80 lines of code). It wraps setTimeout/setInterval;\nwhen a callback's source text contains a summarizer anchor (e.g. the [AgentSummary] Timer fired\nlog line), it returns an inert handle instead of arming the timer. Every other timer passes\nthrough untouched. In the OpenTelemetry export the suppressed requests are\nclaude_code.api_request events with query_source = agent_summary.

\n

Why a timer hook rather than something simpler: the module ships as precompiled Bun bytecode, so\nediting its JS text inside the binary changes nothing, and the API client does not go through a\nwrapped globalThis.fetch. But Function.prototype.toString still returns a callback's source\neven when it runs from bytecode, so the timer can be recognised by a string inside it. The inert\ntimer uses exactly 2³¹−1 ms: Node and Bun treat a larger delay as 1 ms, so an "infinite" delay\nwould fire at once.

\n

Install

\n
  1. Put no-agent-summary.js somewhere stable; note its absolute path.

  2. Set BUN_OPTIONS globally so every Claude Code process gets it. One of:

    \n # ~/.profile, ~/.bashrc, ~/.zshrc\n export BUN_OPTIONS="${BUN_OPTIONS:+$BUN_OPTIONS }--preload /abs/path/no-agent-summary.js"\n

    \n

    \n # ~/.config/fish/config.fish\n set -gx BUN_OPTIONS "--preload /abs/path/no-agent-summary.js"\n

    \n

    \n # ~/.config/environment.d/50-no-agent-summary.conf (systemd user env; also reaches\n # user services and timers; applies when the user manager next starts, usually next login)\n BUN_OPTIONS=--preload /abs/path/no-agent-summary.js\n

    \n

    Or a wrapper named claude earlier on PATH (the case keeps it idempotent when one Claude\n Code process starts another):

    \n

    \n #!/bin/sh\n HOOK=/abs/path/no-agent-summary.js\n case " ${BUN_OPTIONS-} " in\n *" --preload $HOOK "*) ;;\n *) export BUN_OPTIONS="${BUN_OPTIONS:+$BUN_OPTIONS }--preload $HOOK" ;;\n esac\n : "${CC_AGENT_SUMMARY_LOG:=${XDG_RUNTIME_DIR:-/tmp}/no-agent-summary.log}"\n export CC_AGENT_SUMMARY_LOG\n exec /path/to/the/real/claude "$@"\n

  3. Restart the daemon and every already-running session, then start Claude Code from an

    environment that has BUN_OPTIONS:

    \n

    \n claude daemon stop --any\n

\n

Env

\n
variablevalueseffect
CC_AGENT_SUMMARY_MODEoff (default), passoff suppresses the summary timer. pass is the A/B control: loads and logs, arms every timer untouched. Any other value warns on stderr and acts as off.
CC_AGENT_SUMMARY_LOGfile path, optionalAppends preload active mode=… bun=… hooked=… on load, one line per matched timer (first 20), and an exit count.
CC_AGENT_SUMMARY_MARKERfile path, optionalOverwritten on load with the preload active … line.
\n

Nuances

\n\n

Verify (after every update)

\n

  1. Preload loads:

    \n BUN_OPTIONS="--preload $HOME/.local/share/no-agent-summary.js" CC_AGENT_SUMMARY_LOG=/tmp/nas.log claude --version && cat /tmp/nas.log\n

    \n

    Expect preload active mode=off …. No line: BUN_OPTIONS did not reach the process, or the\n path is not absolute.

  2. Timer suppressed: with the same BUN_OPTIONS and CC_AGENT_SUMMARY_LOG=/tmp/nas.log, run

    a background subagent for a minute or two. The log shows\n summary timer #1 suppressed (setTimeout, delay=30000) and the agent's panel status stops\n updating. If you export OpenTelemetry, query_source = agent_summary should stay at zero; this\n is the only check that catches every failure mode.

\n

Fail-open

\n

Matching is by source text: an anchor must sit inside the callback passed to the timer. If an\nupdate breaks that, the hook matches nothing and summaries silently come back. Ways it can happen:

\n\n

So re-run Verify after every update.

\n

Effect

\n\n

Tested versions

\n

Linux x64 binary from npm @anthropic-ai/claude-code-linux-x64 (its sha256 equals the native\ninstaller's manifest.json checksum). Static: the extracted bundle's summary timer callback\ncarries a hook anchor. Live: claude -p --model haiku with\nCLAUDE_CODE_AGENT_PROGRESS_SUMMARIES=1, one subagent doing 8 steps of ~20 s, counting\n[AgentSummary] Forking in --debug-file.

\n
versionpublishedsha256staticsummary forks in a ~2.5-min agent run: no hook / hook pass / hook offnotes
2.1.3122026-10-274f4178ce41d8OK5 / 5 / 0latest on 2026-10-28; interactive: 6 no hook, 0 off
2.1.3102026-10-23b73676430af1OK5 / 5 / 0
2.1.3082026-10-22356733f185faOK5 / 6 / 0stable on 2026-10-28; the pass run's agent took 9 steps instead of 8
2.1.3012026-10-15bc1aad9982c7OK5 / 5 / 0same with earlier hook builds; interactive off also 0; in daily use since 2026-10-26, 0 agent_summary requests in telemetry
2.1.2802026-09-221e08503dbdf3OK1 / 1 / 0 (timer fired 11 / 11 / 0)interactive: -p cannot enable summaries on this version. The agent sat at a permission prompt, so later timers skipped the unchanged transcript
2.1.2572026-09-019a64bda9d872OK1 / 1 / 0 (timer fired 11 / 11 / 0)same as 2.1.280
\n

5 / 5 / 0 = the fork happens on this version, merely loading the hook changes nothing, and off\nremoves it.

\n

Why there is no setting for this

\n\n

Timeline (2026)

\n
version (published)what changed
2.1.32 (Feb 5)the code first appears; dead in public builds
2.1.72 (Mar 9)reachable as an SDK opt-in
2.1.117 (Apr 21)reachable in the interactive CLI behind the fork gate or a server rollout
≤ 2.1.220 (Jul 24)forked skills are always summarized
2.1.232 (Aug 13)on by default for interactive background agents
2.1.300 (Oct 14)interval becomes server-tunable, 30–240 s
2.1.310 (Oct 23)the cheaper short mode lands, switched off
\n

In our telemetry its weekly share of spend went from 3.5–7 % in July (the fork gate was already\nopen for us) to 7.3 % and then 11.8 % in the week we picked up 2.1.233, and to about 16 % by\nmid-October.

\n

License and disclaimer

\n

MIT © 2026 Flamerix AI. Provided as is, without warranty of any kind;\nyou use it at your own risk. Flamerix AI is not liable for any damage, data loss or account\naction arising from its use. Changing a client's runtime behaviour may conflict with the terms of\nthe service you use it with; checking that is on you.

\n

"Claude" and "Claude Code" are trademarks of Anthropic, PBC. This project is independent and is\nnot affiliated with, sponsored or endorsed by Anthropic.

","headings":[{"level":2,"text":"TL;DR","id":"tl-dr"},{"level":2,"text":"The problem","id":"the-problem"},{"level":2,"text":"The fix (how it works)","id":"the-fix-how-it-works"},{"level":2,"text":"Install","id":"install"},{"level":3,"text":"Env","id":"env"},{"level":2,"text":"Nuances","id":"nuances"},{"level":2,"text":"Verify (after every update)","id":"verify-after-every-update"},{"level":3,"text":"Fail-open","id":"fail-open"},{"level":2,"text":"Effect","id":"effect"},{"level":2,"text":"Tested versions","id":"tested-versions"},{"level":2,"text":"Why there is no setting for this","id":"why-there-is-no-setting-for-this"},{"level":3,"text":"Timeline (2026)","id":"timeline-2026"},{"level":2,"text":"License and disclaimer","id":"license-and-disclaimer"}]}}