Fork of flamerix-ai's no-agent-summary (Claude Code agent_summary off switch), v3.1: same blocking code, plus a per-build self-check that warns instead of failing silently, a session-start check,…

A developer published v3.1 of a fork of flamerix-ai's no-agent-summary hook for Claude Code, keeping the upstream code that blocks agent summaries unchanged while adding a per-build self-check that warns inside the session instead of failing silently when a Claude Code update breaks the hook's binary anchors. The fork also adds a session-start check, status.sh for listing which running Claude Code processes are hooked, and an install.sh that writes the hook, shell config and settings.json entries and can uninstall them byte-identically. Testing showed the hook cut summary calls during a ~175 s subagent run from 5 to 0, while disableAgentView: true still produced 5 calls and CLAUDE_CODE_FORK_SUBAGENT=0 stopped them only by disabling fork subagents entirely.

Fork of flamerix-ai's gist https://gist.github.com/flamerix-ai/c3905705cc4205e5de3011fa2e74efce v3 . The code that blocks the summaries is upstream's, unchanged. This fork adds what makes it safe to leave installed across Claude Code updates. Upstream's full README follows the line below, unchanged. - Fails loudly, not silently, inside the session. Once per Claude Code build the hook scans the binary for the anchors it matches on ~50 ms on a 276 MB build, cached by path + size + mtime and records the verdict. A session-start check check.sh , added to Claude Code's settings.json by the installer then shows, inside the session, agent-summary blocker: this Claude Code build … no longer contains the code it blocks when an update broke the match, or agent-summary blocker: NOT loaded in this session when the session was started without BUN OPTIONS . It is silent when all is well. The hook's own stderr line is not enough: tested in an interactive session, Claude Code's full-screen UI draws over it and it only reappears after exit. - Proof it caught one. The first suppressed summary timer on each build is recorded, so you can see the hook did its job on the version you run, not only that it loaded. - status.sh lists every build checked anchors present, suppression seen and every running Claude Code process as hooked or NOT hooked restart it . Each hooked process leaves a marker while it runs, because macOS does not expose another process's environment. - install.sh copies the hook to ~/.local/share/no-agent-summary/ a path without spaces, since BUN OPTIONS splits on whitespace , adds one idempotent block to ~/.zshrc or ~/.bashrc , adds the session-start check to $CLAUDE CONFIG DIR/settings.json default ~/.claude ; existing hooks kept, previous file saved as settings.json.nas-bak ; needs python3 , and checks that claude --version loads the hook. install.sh --uninstall removes all three tested: settings and rc file come back byte-identical . git clone https://gist.github.com/c4511b8642c9d7179ab5761ff6473871.git no-agent-summary && bash no-agent-summary/install.sh Restart running sessions afterwards; status.sh names the ones still unhooked. Summary calls during one ~175 s subagent run, counted from AgentSummary Forking in --debug-file : | session | how summaries were on | no hook | hook pass | hook off | |---|---|---|---|---| | headless claude -p --model haiku | CLAUDE CODE AGENT PROGRESS SUMMARIES=1 | 5 | 5 v3 | 0 v3, and v3.1 | | interactive TUI, background agent | default, nothing set | n/a | 5 v3.1 | 0 v3.1 | - The session-start check, in real interactive sessions: a deliberately broken anchor showed the "no longer contains" message; a session started without BUN OPTIONS showed "NOT loaded"; a normal hooked session showed nothing. - Two settings people suggest instead, tested the same way with no hook: disableAgentView: true → still 5 calls it only hides the agents screen ; "env": {"CLAUDE CODE FORK SUBAGENT": "0"} → 0 calls, but it also turns off fork subagents. If you never use forks, that one line is the simplest fix. - Each summary call re-read the subagent's whole context median 37,250 tokens, from cache to return a 14-token label 10 calls . - Upstream's matching costs almost nothing: 2.2 ms over 4.8 minutes of an interactive session 4,566 setTimeout calls, 3,305 callbacks stringified . So it is left as is. - The gate admits the macOS native path ~/.local/share/claude/versions/<ver and the desktop app's bundled copy …/Claude/claude-code/<ver /<hash /claude.app/Contents/MacOS/claude ; Bun.main is /$bunfs/root/cli in both . Agents were not run in the desktop app. - Size on one user's machine: replaying the 30-s timer over a week of transcripts 190 background agents, mostly Opus 5.5 puts summaries at about 8% of list-price-equivalent spend. The replay was checked against a live run 5 calls predicted, 5 measured . Lower than upstream's 16%, partly because Opus 5.5 cache reads cost 0.05× input and the replay assumes a warm cache. by Flamerix AI https://flamerix.ai · MIT License Tested on Linux, Claude Code 2.1.257–2.1.312; macOS reported working by others see Tested versions . The binary is not modified BUN OPTIONS=--preload . An update can silently undo it, so see Verify. Every ~30 seconds, Claude Code re-sends each background agent's full transcript to the model just to fill that agent's status line in the agents panel. no-agent-summary.js is a Bun --preload that stops that timer without modifying the Claude Code binary. curl -fsSL https://gist.githubusercontent.com/flamerix-ai/c3905705cc4205e5de3011fa2e74efce/raw/no-agent-summary.js -o ~/.local/share/no-agent-summary.js claude daemon stop --any BUN OPTIONS="${BUN OPTIONS:+$BUN OPTIONS }--preload=$HOME/.local/share/no-agent-summary.js" claude To make it permanent for every Claude Code process, see Install install . Every ~30 seconds, for every background agent, Claude Code sends that agent's entire transcript to the agent's own model usually Opus and asks it to "describe your most recent action in 3-5 words". The answer only updates the agent's status line in the agents panel; it never reaches the model or your conversation. There is no setting that turns it off, and since 2.1.232 August 2026 it has been on by default. The anomaly was detected by DRIM https://flamerix.ai in Claude Code's OpenTelemetry export: grouping claude code.api request events by query source showed agent summary costing more than the main conversation itself . | query source = agent summary | week before the hook | 2 days after | |---|---|---| | share of all Claude Code spend | 16.4 % main conversation: 15.7 % | 0 % | | share of all API requests | 19.7 % , about 1 in 5 | 0 % | | part of that spend on Opus | 96 % | — | | input tokens per output token | ≈ 9,000 : 1 | — | Spend here means Claude Code's own per-request estimate cost usd , not an invoice: on a subscription, what you lose is rate-limit headroom. We are not the only ones who measured it: 86879 https://github.com/anthropics/claude-code/issues/86879 collects four independent measurements of 18–26 %. no-agent-summary.js is a Bun preload ~70 lines of code . It wraps only the global setTimeout , the one the summary timer is armed through; when a callback's source text contains a summarizer anchor e.g. the AgentSummary Timer fired log line , it returns an inert handle instead of arming the timer. Every other timer passes through untouched. In the OpenTelemetry export the suppressed requests are claude code.api request events with query source = agent summary . Why a timer hook rather than something simpler: the module ships as precompiled Bun bytecode, so editing its JS text inside the binary changes nothing, and the API client does not go through a wrapped globalThis.fetch . But Function.prototype.toString still returns a callback's source even when it runs from bytecode, so the timer can be recognised by a string inside it. The inert timer uses exactly 2³¹−1 ms: Node and Bun treat a larger delay as 1 ms, so an "infinite" delay would fire at once. The hook installs only inside Claude Code: Bun.main must be /$bunfs/root/cli the compiled entry, the same on every row below and process.execPath must be a Claude Code install. Any other bun , or a compiled Bun binary with another entry name, loads the file and does nothing. | install channel Linux, measured with claude --version | process.execPath | |---|---| | nix | …/bin/.claude-wrapped | | npm @anthropic-ai/claude-code | …/@anthropic-ai/claude-code/bin/claude.exe .exe on Linux too | | npm platform package | …/@anthropic-ai/claude-code-linux-x64/claude | | native installer | ~/.local/share/claude/versions/<version | macOS and Windows are not measured; the hook installs there only if they produce these same shapes, and Verify step 1 tells you. One known pass-through: a foreign binary built with bun build --compile --outfile cli and renamed claude ; there, only timers whose callback carries an anchor change. 1. Put no-agent-summary.js somewhere stable; note its absolute path. 2. Set BUN OPTIONS globally so every Claude Code process gets it. Write --preload=<path , with = : BUN OPTIONS reaches every bun on the machine, and with a space --preload <path bun subcommands break bun install → error: Script not found "install" . Claude Code reads both forms. One of: ~/.profile, ~/.bashrc, ~/.zshrc export BUN OPTIONS="${BUN OPTIONS:+$BUN OPTIONS }--preload=/abs/path/no-agent-summary.js" ~/.config/fish/config.fish set -gx BUN OPTIONS "--preload=/abs/path/no-agent-summary.js" ~/.config/environment.d/50-no-agent-summary.conf systemd user env; also reaches user services and timers; applies when the user manager next starts, usually next login BUN OPTIONS=--preload=/abs/path/no-agent-summary.js Or a wrapper named claude earlier on PATH the case keeps it idempotent when one Claude Code process starts another, and also recognises the v2 space form : bash /bin/sh HOOK=/abs/path/no-agent-summary.js case " ${BUN OPTIONS-} " in " --preload=$HOOK " | " --preload $HOOK " ;; export BUN OPTIONS="${BUN OPTIONS:+$BUN OPTIONS }--preload=$HOOK" ;; esac : "${CC AGENT SUMMARY LOG:=${XDG RUNTIME DIR:-/tmp}/no-agent-summary.log}" export CC AGENT SUMMARY LOG exec /path/to/the/real/claude "$@" 3. Restart the daemon and every already-running session, then start Claude Code from an environment that has BUN OPTIONS : claude daemon stop --any | variable | values | effect | |---|---|---| | CC AGENT SUMMARY MODE | off default , pass | off suppresses the summary timer. pass is the A/B control: loads and logs, arms every timer untouched. Any other value warns on stderr and acts as off . | | CC AGENT SUMMARY LOG | file path, optional | Appends preload active mode=… bun=… hooked=global.setTimeout on load, one line per matched timer first 20 , and an exit count. | | CC AGENT SUMMARY MARKER | file path, optional | Overwritten on load with the preload active … line. | - Restart the daemon after install. The daemon, pty host and pre-warmed bg-spare sessions inherit the environment of the client that started the daemon, so a daemon started before BUN OPTIONS was set keeps spawning unhooked sessions. Hence claude daemon stop --any . - Headless runs need it too: claude -p , cron, CI, editor integrations. - Platform: Linux tested by us, macOS darwin-arm64 reported working by others, Windows untested see Which processes it touches which-processes-it-touches . - npm --ignore-scripts : bin/claude stays a shell stub and Bun never starts, so the hook never runs. - Upgrading from v2: overwrite the file in place, switch BUN OPTIONS to the = form and restart the daemon. If both forms name the same path, bun loads it once. Two different paths say an old copy kept beside the new one both load: a second v3 copy is a no-op, but v2 has no such guard, so do not leave a v2 path in BUN OPTIONS . - A/B: CC AGENT SUMMARY MODE=pass loads the hook but arms every timer; the summaries come back, which shows the off result is the hook's doing. - Background processes: daemon, pty host and bg-spare must carry --preload in their environment /proc/<pid /environ on Linux ; if not, restart the daemon. 1. Preload loads: BUN OPTIONS="--preload=$HOME/.local/share/no-agent-summary.js" CC AGENT SUMMARY LOG=/tmp/nas.log claude --version && cat /tmp/nas.log Expect preload active mode=off … . No line: BUN OPTIONS did not reach the process, or the 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 summary timer 1 suppressed setTimeout, delay=30000 and the agent's panel status stops updating. If you export OpenTelemetry, query source = agent summary should stay at zero; this is the only check that catches every failure mode. Matching is by source text : an anchor must sit inside the callback passed to the timer. If an update breaks that, the hook matches nothing and summaries silently come back. Ways it can happen: - the log line or query-source id is renamed; - the callback is passed via fn.bind ... no source in toString or another wrapper; - the strings move to a shared constant outside the callback; - the timer moves off the global setTimeout setInterval , require "timers" , timers/promises , a scheduler loop . So re-run Verify after every update. - We run it under every Claude Code process on our machine 2.1.301 . Since then there have been zero agent summary requests, and no other side query grew to take its place. - Subagents, background agents, forked skills and background sessions run normally; only the summary fork is skipped. - Visible change: the per-agent panel status stops updating; SDK task progress has no summary . - Overhead: one Function.prototype.toString per distinct timer callback, cached in a WeakMap . claude --version : ~10 ms → ~17 ms one measurement . Linux x64 binary from npm @anthropic-ai/claude-code-linux-x64 its sha256 equals the native installer's manifest.json checksum . Static: the extracted bundle's summary timer callback carries a hook anchor. Live: claude -p --model haiku with CLAUDE CODE AGENT PROGRESS SUMMARIES=1 , one subagent doing 8 steps of ~20 s, counting AgentSummary Forking in --debug-file . The two v3 rows are this script, re-run on 2026-10-29. The rows below them were measured with v2. | version | published | sha256 | static | summary forks in a ~2.5-min agent run: no hook / hook pass / hook off | notes | |---|---|---|---|---|---| | 2.1.312 v3 | 2026-10-27 | 4f4178ce41d8 | OK | 5 / 6 / 0 | the pass run took 232 s on a loaded machine, so one more 30 s tick fit; off with the gist file itself: 0 | | 2.1.301 v3 | 2026-10-15 | bc1aad9982c7 | OK | 5 / 5 / 0 | run through the Nix-packaged binary rather than the npm one | | 2.1.312 | 2026-10-27 | 4f4178ce41d8 | OK | 5 / 5 / 0 | latest on 2026-10-28; interactive: 6 no hook, 0 off | | 2.1.310 | 2026-10-23 | b73676430af1 | OK | 5 / 5 / 0 | | | 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 | | 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 | | 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 | | 2.1.257 | 2026-09-01 | 9a64bda9d872 | OK | 1 / 1 / 0 timer fired 11 / 11 / 0 | same as 2.1.280 | 5 / 5 / 0 = the fork happens on this version, merely loading the hook changes nothing, and off removes it. Reported by others | platform | version | checked | by | |---|---|---|---| | macOS 26.7.1, native darwin-arm64, bun 1.4.4 | 2.1.312 | static: the 3–5 words prompt, the timer 30 s, clamped 30–240 s , no off switch; live: the preload loads, and an interactive session with a background subagent logged summary timer 1 suppressed setTimeout, delay=30000 . Token numbers not checked no OTEL export | lostsock https://news.ycombinator.com/user?id=lostsock , HN, 2026-10-29 | On claude -p : headless runs don't arm the summary timer by default. Our live tests set CLAUDE CODE AGENT PROGRESS SUMMARIES=1 for that reason. The default-on overhead is in interactive sessions with background agents. - The documented switch only turns it on. The SDK option agentProgressSummaries defaults to false , but in the bundle it is one term of an OR, and every code path that writes it sets true . So false changes nothing, and the undocumented CLAUDE CODE AGENT PROGRESS SUMMARIES can only enable summaries too. - The interval belongs to the server. It comes from a per-model-family server flag and is clamped to 30–240 s. The default is already the minimum, and no value disables the timer. - The obvious env vars miss. DISABLE NON ESSENTIAL MODEL CALLS , which some packagers set, does not occur in the binary at all. CLAUDE CODE FORK SUBAGENT=0 and CLAUDE CODE DISABLE BACKGROUND TASKS=1 do stop it, but only by taking fork subagents or background agents with it. - The prompt cache makes it cheaper, not cheap. About 98 % of these calls re-read the transcript from cache; the ~2 % that hit a cold cache carry over a third of its cost. - Cost tools that read transcripts don't see it. These requests are not written to the session logs on disk 104358 https://github.com/anthropics/claude-code/issues/104358 ; only the OpenTelemetry export shows them. The docs section on background token usage doesn't list it either, while Agent View's row summaries are documented as a Haiku-class model refreshing every few minutes. - A cheaper variant already exists, switched off. 2.1.310 ships a short mode: about 2k tokens of notes instead of the full transcript, optionally written by a smaller model. The default is still the full transcript, and only server flags can change it. | 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 | In our telemetry its weekly share of spend went from 3.5–7 % in July the fork gate was already open for us to 7.3 % and then 11.8 % in the week we picked up 2.1.233, and to about 16 % by mid-October. - docs — first macOS report darwin-arm64, 2.1.312 added to Tested versions tested-versions . Thanks to lostsock https://news.ycombinator.com/user?id=lostsock . - v3 — --preload=<path everywhere the space form broke bun subcommands ; the hook installs only inside Claude Code Bun.main plus process.execPath , see Which processes it touches which-processes-it-touches ; a second load in the same process is a no-op. Thanks to Bedz01 https://gist.github.com/Bedz01 for the --preload= form and the Claude-Code-only gate gist comment, 2026-10-29 . - v3 — wraps only the global setTimeout , the one the summary timer is armed through v2 also wrapped setInterval and require "timers" . MIT © 2026 Flamerix AI https://flamerix.ai . Provided as is , without warranty of any kind; you use it at your own risk. Flamerix AI is not liable for any damage, data loss or account action arising from its use. Changing a client's runtime behaviour may conflict with the terms of the service you use it with; checking that is on you. "Claude" and "Claude Code" are trademarks of Anthropic, PBC. 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