Publish chat background work and show background shells above the chat input - #338723
Merged
Anthony Kim (anthonykim1) merged 22 commits intoOct 1, 2026
Merged
Conversation
Publish Copilot's running and waiting shells and running background subagents as AHP chat background work, and project the shells onto the Agents window's Background Shells pill.
Copilot started reviewing on behalf of
Anthony Kim (anthonykim1)
September 29, 2026 17:12
View session
Contributor
There was a problem hiding this comment.
Copilot review overview
🟡 Changes recommended
The abort-refresh race and protocol projection issues can leave stale or misidentified background work.
Review effort: Balanced
Findings: 1
Open (2)
What changed in this PR
Publishes chat-owned background work through AHP and presents active shells in the Agents window.
Changes:
- Adds AHP background-work state, actions, reducers, metadata, and synchronization.
- Watches Copilot tasks and publishes shells and subagents independently of turns.
- Adds the Background Shells pill, live details, keyboard handling, accessibility help, and tests.
| File | Description |
|---|---|
src/vs/platform/actionWidget/browser/actionList.ts |
Supports activatable, bottom-aligned detail panels. |
src/vs/platform/actionWidget/test/browser/actionList.test.ts |
Tests detail activation and layout. |
src/vs/platform/agentHost/common/agent.ts |
Adds the background-work watch contract. |
src/vs/platform/agentHost/common/meta/copilotBackgroundWorkMeta.ts |
Reads and writes Copilot shell metadata. |
src/vs/platform/agentHost/common/state/protocol/action-origin.generated.ts |
Registers generated action origins. |
src/vs/platform/agentHost/common/state/protocol/channels-chat/actions.ts |
Defines background-work actions. |
src/vs/platform/agentHost/common/state/protocol/channels-chat/reducer.ts |
Reduces background-work updates. |
src/vs/platform/agentHost/common/state/protocol/channels-chat/state.ts |
Defines background-work protocol state. |
src/vs/platform/agentHost/common/state/protocol/common/actions.ts |
Exports the new action types. |
src/vs/platform/agentHost/common/state/protocol/version/registry.ts |
Registers action protocol versions. |
src/vs/platform/agentHost/common/state/sessionState.ts |
Projects background work between chat state and summaries. |
src/vs/platform/agentHost/node/agentHostStateManager.ts |
Mirrors background work into session catalogs. |
src/vs/platform/agentHost/node/agentService.ts |
Manages watches across chat subscribers. |
src/vs/platform/agentHost/node/copilot/copilotAgent.ts |
Connects chat watches to live Copilot sessions. |
src/vs/platform/agentHost/node/copilot/copilotAgentSession.ts |
Reconciles and publishes Copilot background tasks. |
src/vs/platform/agentHost/test/node/agentHostStateManager.test.ts |
Tests catalog mirroring and turn independence. |
src/vs/platform/agentHost/test/node/agentService.test.ts |
Tests subscriber watch lifecycle. |
src/vs/platform/agentHost/test/node/copilotAgentSession.test.ts |
Tests task publication, refresh, and reconciliation. |
src/vs/sessions/contrib/chat/browser/sessionBackgroundShellsControl.ts |
Builds shell pill rows and live details. |
src/vs/sessions/contrib/chat/browser/sessionChatInputToolbar.ts |
Adds the shell source to Agents input pills. |
src/vs/sessions/contrib/chat/browser/sessionsChatAccessibilityHelp.ts |
Documents shell picker accessibility. |
src/vs/sessions/contrib/chat/test/browser/sessionBackgroundShellsControl.test.ts |
Tests shell presentation and updates. |
src/vs/sessions/contrib/providers/agentHost/browser/baseAgentHostSessionsProvider.ts |
Projects AHP shells into Sessions state. |
src/vs/sessions/contrib/providers/agentHost/test/browser/localAgentHostSessionsProvider.test.ts |
Tests per-chat shell projection. |
src/vs/sessions/services/sessions/common/session.ts |
Adds provider-neutral shell state. |
src/vs/workbench/browser/chatDropdownPill.ts |
Routes row activation to details. |
src/vs/workbench/contrib/chat/browser/chatInputPills.ts |
Adds the standard shell pill source. |
src/vs/workbench/contrib/chat/browser/sessionChatPillOptions.ts |
Defines shell pill labels and behavior. |
src/vs/workbench/contrib/chat/common/sessionChatPills.ts |
Registers the shell pill kind. |
src/vs/workbench/contrib/chat/test/browser/chatInputPills.test.ts |
Tests shell pill visibility and placement. |
src/vs/workbench/contrib/chat/test/common/sessionChatPills.test.ts |
Tests shell visibility configuration. |
src/vs/workbench/test/browser/chatPills.test.ts |
Tests dropdown activation options. |
💡 Configure MCP servers for context-aware, tailored reviews. Learn more in the docs.
Contributor
Screenshot ChangesBase: Changed (3)
|
| Before | After |
|---|---|
 |
 |
chat/aiCustomizations/aiCustomizationManagementEditor/McpMigration/Light
| Before | After |
|---|---|
 |
 |
chat/aiCustomizations/aiCustomizationManagementEditor/DiscoverPluginsLoadingMore/Light
| Before | After |
|---|---|
 |
 |
2 insignificant change(s) omitted (≤20 px, Δ≤2). See CI logs for details.
Follow the protocol change that starts background work with shells only. The provider still skips kinds it doesn't render, since newer hosts can send more.
Follow the protocol change that drops status from background work. Every listed shell is unfinished, and Copilot never reports a shell as idle. The pill now shows the attached or detached mode and elapsed time.
The async shell is now published as background work from a separate task-list read, so its timing against the tool calls isn't part of this scenario.
Anthony Kim (anthonykim1)
changed the title
Follow the protocol change that removes the unused terminal field. Nothing in VS Code set or read it.
Move the Background Shells pill control and the background work projection into the workbench so the editor window's Agent Host chat input can show the same pill as the Agents window. Share the pill's accessibility help between both windows.
Anthony Kim (anthonykim1)
changed the title
Addresses review feedback on stale shells after a client restart or crash. A session that replaced another started with an empty baseline, so shells the new runtime no longer reported stayed listed. The host now passes the chat's current background work when a watch attaches, and the session removes entries missing from its first read.
Addresses review feedback on the abort race. Aborting a turn bumped the task status revision without queuing a read, so a read in flight was discarded and the detached shell poll could stop for good, since detached shells report no exit on their own. The session now reads again once the abort settles.
Match microsoft/agent-host-protocol#482: background shells can link their terminal, and background subagents are their own kind that points at the subagent's chat. The Background Shells pill still shows shells only.
Running background agents are published with their chat. Idle ones have already reported back, so they're left out. Shells don't set a terminal yet; that waits for output streaming.
Addresses review thread #338723 (comment). Rows used Copilot's shell ID from _meta as their identity, which the protocol doesn't guarantee is unique. Key rows by the entry id instead, and show Copilot's shell ID separately, only when the agent reports one.
Running background subagents are now published as background work. Those actions come from a separate task-list read, so their timing against the subagent's tool calls isn't part of this scenario, and CI's snapshot comparison failed on every platform. Ignore them here, as the read-shell scenario already does.
A failing local run left this .actual file next to the retained background subagent snapshot, and it was committed by mistake. Hygiene rejects it, and the test runner logs when it deletes it, which fails the no-console-output check.
Match microsoft/agent-host-protocol#482 at d513c6fb, which says background work lists only active work.
Keep both sides where main and this branch added to the same spots: main's chat canvases next to background shells in the sessions model and provider, main's canvas test next to the background shell projection test, and the combined imports. Take main's move of gitHubMcpServerUrl to platform/github.
Contributor
Author
(Perhaps we dont show attached, but show detached when it's detached)? So if you dont see detached, it's attached (similar to github app).
|
Contributor
Author
|
Updated screenshot: 
|
Anthony Kim (anthonykim1)
marked this pull request as ready for review
September 30, 2026 22:20
Contributor
📬 CODENOTIFYThe following users are being notified based on files changed in this PR: Sandeep Somavarapu (@sandy081)Matched files:
Ladislau Szomoru (@lszomoru)Matched files:
|
Anthony Kim (anthonykim1)
marked this pull request as draft
September 30, 2026 22:23
Attached is the common case, so an unlabeled shell reads as attached and only detached shells carry a label, matching the GitHub app.
Mirror modifiedAt alongside status, activity, and backgroundWork when forwarding a chat's summary to its session, and set both the default chat's background shells and its modified time.
Anthony Kim (anthonykim1)
marked this pull request as ready for review
September 30, 2026 22:52
Anthony Kim (anthonykim1)
marked this pull request as draft
September 30, 2026 23:08
Take agent-host-protocol at ab694bfd, the head of microsoft/agent-host-protocol#482. The only change is the shortened backgroundWork doc text from its review.
Anthony Kim (anthonykim1)
marked this pull request as ready for review
October 1, 2026 00:23
Anthony Kim (anthonykim1)
marked this pull request as draft
October 1, 2026 00:42
microsoft/agent-host-protocol#482 dropped ChatSummary.backgroundWork, so session subscribers no longer receive every chat's background work. The Agents window pill now reads ChatState.backgroundWork through the active session's chat subscription, like the editor window already did, and the state manager no longer mirrors the list into chat summaries. Syncs the protocol to microsoft/agent-host-protocol@dc9ff6b0.
Anthony Kim (anthonykim1)
marked this pull request as ready for review
October 1, 2026 03:06
roblourens
previously approved these changes
Oct 1, 2026
Anthony Kim (anthonykim1)
marked this pull request as draft
October 1, 2026 14:54
Main now offers every pill kind in both windows through SESSION_CHAT_PILL_KINDS, which already includes Background Shells, so the editor window's offeredPillKinds list goes away and the background shells source sits next to main's new Subagents pill. Keep both sides' accessibility help, imports, and tests, and pass main's new ICommandService argument in the editor window's background shells test.
Anthony Kim (anthonykim1)
marked this pull request as ready for review
October 1, 2026 15:38
Raymond Zhao (rzhao271)
approved these changes
Oct 1, 2026
This was referenced Oct 1, 2026
Closed
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Depends on: microsoft/agent-host-protocol#482
Replaces: #338713
Related: #336348, #337684
chat/backgroundWorkSetandchat/backgroundWorkRemoved: shells that keep running after their tool call returns (attached or detached), and running background subagents with their chat. Copilot only for now; Claude and Codex can follow.ChatSummary, so it isn't broadcast to every session subscriber. Both pills readChatState.backgroundWork: the Agents window through the chat subscription it opens while the session is active, and the editor window from the chat it shows.session.rpc.tasks.list()onsession.background_tasks_changedand when a client starts watching the chat, and polltasks.refresh()every 5 seconds while a watched chat has detached shells._meta. Only detached shells carry a Detached label, so an unlabeled shell is attached, matching the GitHub app. Rows are keyed by the protocolid, and other kinds, subagents included, aren't shown yet.terminalunset until shell output streaming lands, and leave turn completion and Stop unchanged.scripts/sync-agent-host-protocol.tsatdc9ff6b0, the head of Add background work to chat state for shells and subagents agent-host-protocol#482, so the two PRs can merge back to back.mainalready has chat: Add durable chat move and reorder contracts agent-host-protocol#484 from agentHost: Sync durable chat move and reorder protocol #339007, so the only protocol changes here are Run tests in Electron #482's background work. Once Run tests in Electron #482 merges,.ahp-versionshould point at its merged commit.Still to do: clear a chat's background work when its session is disposed.
How to test:
sleep 120with its shell tool in async mode.sleep 120withdetach: true: the pill reads 2 Background Shells, and only the new row shows Detached.Validation
maininfa17532f:npm run typecheck-client,npm run valid-layers-check, and ESLint on the 37 changed.tsfiles passed.npm run test-nodeon the Agent Host session, service, state manager, and agent tests: 2022 passing; on the protocol server handler: 164 passing; on the Agent Hostcommontests: 931 passing../scripts/test.shon the pill, accessibility help, and sessions provider tests: 584 passing. The full Copilot E2E suite passed in replay mode withmain's Copilot SDK 1.0.16: 233 passing.dc9ff6b0; compared withmain, it only adds background work types, actions, and reducer cases.Inspirations from
session.background_tasks_changedwith a revision counter extends_reconcileSubagentTaskStatuses.idfollows the protocol's rule thatidis opaque.ChatStatefollows_createChatCurrentTurnChangesObservable, which subscribes to the chat throughcreateActiveSessionSubscriptionObsonly while the session is active.AgentService._watchChatHistory.createSessionPullRequestPillData.