[teamleaderleo]

Problem

On 2026-10-30 one daemon's session list with tools was 17 MB, past acpmux's largest reply, and acpmux refused it as message.too_large. #28182 makes _acpmux/sessions and _acpmux/watch with no limit answer such a list in byte-bounded pages: the first rows with a nextCursor, the rest from _acpmux/sessions {cursor, ...the same params less enabled}. The in-repo Rust clients that ask for the whole list read only the first reply, so against a paged daemon they would see only the first page.

A list that fits is still one reply with no cursor, so these clients behave as before against an older acpmux.

What changed

• cmux-tui/crates/cmux-tui-core/src/server/agent_session_link.rs: AcpmuxLink::call_whole_list does what acpmux's Client::whole_list does. With a limit it makes one plain call, since that caller pages for itself. Otherwise it follows nextCursor through _acpmux/sessions with the same params less enabled and appends each page's sessions. timeout bounds each reply.
• agent_session_children.rs (agent-session-children), agent_session_stream.rs (the attach's _acpmux/watch, whose list picks the children the attachment follows) and agent_transfer/agent_update.rs (the update plan's chat list) read their lists through it. The watch's first page and its cursor pages are merged before descendant_ids reads them.
• cmux-next-ios/rust/crates/cmux-mobile-host/src/notify_waiting.rs: the phone push watch asks for each next page by its cursor. The classifier loads every page's rows and each row is observed. A failed page reconnects the watch, which reads the list again from its start. notify.rs: doc comment only.
• agent_chat_notices.rs already pages with a limit and is unchanged.
• Tests: agent_session_attach_tests.rs gives the fake acpmux a two-page _acpmux/sessions and a two-page watch. session_children_reads_every_page_of_a_list_too_big_for_one_reply and session_children_follows_a_child_only_a_later_watch_page_names cover cmux-tui-core. a_watch_list_past_one_reply_reads_its_rest_from_the_cursor covers mobile-host.

Tests

Red/green are both on hosted Linux through cmux-ci test at the PR head. The red run used the test commit alone and the green run used the fix.

bash scripts/ci/init-submodule.sh ghostty-next && ./scripts/install-zig-ci.sh
(cd cmux-tui && cargo test -p cmux-tui-core --lib session_children)
(cd cmux-next-ios/rust && cargo test -p cmux-mobile-host notify_waiting)

• Red at d42891e (tests only): https://github.com/manaflow-ai/cmux/actions/runs/41040507069. All three new tests fail. The two cmux-tui-core tests time out waiting for the _acpmux/sessions {cursor} frame, and the mobile-host test fails its first-page assertion. The 16 existing tests in the filter pass.
• Green at a417b33 (fix): https://github.com/manaflow-ai/cmux/actions/runs/41040613716. cmux-tui-core 9/9 and mobile-host 10/10 pass. The job shows as failed only because the command ends in exit 1 so that its log prints.

Observed / Not run

• Observed: the runs above. rustfmt --check is clean on every changed file.
• Not run: a live daemon with acpmux: a session list too large for one message goes in pages #28182 and a list past one reply. Clippy and the full cmux-tui suite are left to this PR's CI.

Changelog

none

Agent session: agent session

🤖 Generated with Claude Code

[blacksmith-sh]

Found 3 test failures on Blacksmith runners:

Failures

Test	View Logs
test_a_picked_signing_label_has_a_rerun_alternative (main.RunsOnFallbackTests.test_ a_picked_signing_label_has_a_rerun_alternative)/ test_a_picked_signing_label_has_a_rerun_alternative (main.RunsOnFallbackTests.test_ a_picked_signing_label_has_a_rerun_alternative)	View Logs
test_every_listed_hook_is_one_glaeda_released_with_the_check (main.SigningHooksInSt epWithGlaedaTests.test_every_listed_hook_is_one_glaeda_released_with_the_check)/ test_every_listed_hook_is_one_glaeda_released_with_the_check (main.SigningHooksInSt epWithGlaedaTests.test_every_listed_hook_is_one_glaeda_released_with_the_check)	View Logs
test_no_runs_on_chain_ends_on_the_reserved_side_label (main.RunsOnFallbackTests.tes t_no_runs_on_chain_ends_on_the_reserved_side_label)/ test_no_runs_on_chain_ends_on_the_reserved_side_label (main.RunsOnFallbackTests.tes t_no_runs_on_chain_ends_on_the_reserved_side_label)	View Logs

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[github-actions]

cmux status _{(one comment, edited in place; each line is updated by the job that owns it)}

Review a95e1cb: HQ feed card · gallery before/after runs · checks

App of this head (app.zip, kept 1 day)

gh workflow run reload-build.yml -R manaflow-ai/cmux --ref feat-cmux-next -f tag=pr28273 -f ref=lane/acpmux-rust-clients-pages -f platform=macos -f backend_mode=local

web and size checks: green

Shipped in:

• cmux NEXT nightly 1.0.0-nightly.4130052256501 (28aa638015)

[cursor]

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[teamleaderleo]

Review (codex gpt-6.1-sol xhigh, next-review): SHIP at 17ee908

SHIP at 17ee908

Visual verdict: no images; Leo tries the build

1. [P2] [follow-up] agent_session_link.rs:202: Continuation requests retain the callers’ five-second timeout, but acpmux permits longer pacing delays. Each request without limit costs a full list reservation; after two immediate pages, a third can legitimately wait 10–15 seconds. Such lists fail as BadList, refusing attachment instead of completing pagination. Account for server pacing and the outer client’s request deadline; test a delayed third page.

2. [P2] [follow-up] agent_session_stream.rs:83: Child notifications are discarded while continuation pages load. ReaderSlot::hold drops notifications naming another session until the attachment becomes live. A child created between pages whose paging hash falls before the current cursor appears in no page, and its creation notification is discarded. The attachment consequently misses that child until another list or reconnect. Preserve and replay child changes received during pagination.

Source review completed. Rust tests could not run because this box has neither cargo nor rustc.

Follow-ups:

• Allow paced continuation replies to complete within coordinated request deadlines.
• Retain child-session changes received while assembling the watch list.

[cmux-bot]

cmux-bot approves 17ee908: an independent review passed this exact head (next-review receipt by teamleaderleo). A push needs a new review; a later BLOCK at this head dismisses this approval.

A newer verdict blocks b26524d (no independent SHIP at the head).

[teamleaderleo]

Review (next-review patch-id; carried): SHIP at b26524d

The independent SHIP at 17ee908 carries to this head: the PR's own change (git diff $(git merge-base feat-cmux-next HEAD) HEAD) has the same git patch-id --verbatim (663c8265eb48be17) at both heads, and no merge between them was resolved by hand. Nothing new to review. A newer BLOCK, or any change to the PR's own diff, ends the carry.