[spoukyii]

Problem

When a linked environment delegates a thread here, that thread carries delegatedFrom, naming the remote parent. Every subagent the delegated thread then starts copied it too. makeSubagentChildThread builds the child by spreading the parent thread, so each subagent also claims to be delegated from the remote parent, though the remote environment delegated only the parent thread.

Clients show that claim:

• Mobile, thread header: a subagent of the delegated thread reads "Subagent of <remote parent's title>", naming the wrong thread as its parent (apps/mobile/src/features/threads/ThreadRouteScreen.tsx).
• Web, thread details: the subagent's lineage card shows a "Delegated from" row for the remote parent (DelegatedFromRow in ThreadRelationshipsControl.tsx).

Change

makeSubagentChildThread drops delegatedFrom from what the child inherits, the same way ThreadForkService.plan drops it for a fork of a delegated thread. Nothing else in the child changes.

With it gone, the mobile header falls back to the thread's link origin ("From "), as for any other linked work, and the web card loses the stray row. Completion delivery does not read the child's delegatedFrom: the delegating side tracks its task through its own remote-child record. The approval rollup to the remote parent still reaches the subagent through its delegated parent, as it already did. On main it counted the subagent's requests on both paths.

Scope and approval

This is a small, focused fix for an obvious bug, so it needs no prior issue. #28378 fixed the same defect for forks: "a fork no longer inherits the source thread's pin, auto-settle and delegation state", with the comment "The remote parent delegated the source thread, not its forks." Subagent children are built by a separate function, which #21271, #26035 and #27990 have each corrected for other inherited fields (pin, settle protections, title job). This PR does the same for delegatedFrom.

Verification

apps/server/src/orchestration-v2/SubagentProjection.test.ts extends its existing child-thread case: the parent gets a delegatedFrom, and the child must not carry it.

On main with only the test commit (0d74415), from apps/server, vp test run src/orchestration-v2/SubagentProjection.test.ts:

× resets a subagent child's snooze, title job and remote delegation but keeps its workspace
AssertionError: expected { …(3) } to equal undefined
Tests  1 failed | 8 passed (9)

With the fix, from apps/server:

• vp test run src/orchestration-v2/SubagentProjection.test.ts src/orchestration-v2/ThreadForkService.test.ts: 2 files, 14 tests passed.
• vp run check:changed from the repo root: format, lint, knip, graphql, typecheck (26 packages) and tests beside the change all pass.

In a running setup on Windows: two dev servers, A and B, both with Linked environments on. A was linked to B, and B was added to A's web client. In a thread on A, a real Claude Haiku 5.5 turn called delegate_task to B. B's task used Claude's Task tool to start one subagent. I opened that subagent in the web client and read its thread details Lineage card. The before run is B on main's subagentProjection.ts, the after run B on this branch, each with a fresh delegation:

main:   Lineage: "Run Deleg… on DESKTOP-I1Q6NTM" (A's parent, the delegated-from row), then "Subagent DONE probe" (its real parent)
branch: Lineage: "Subagent DONE check" (its real parent) only

Before (main)	After (this branch)

The "From T3 Code · DESKTOP-I1Q6NTM" badge in the header comes from the thread's link origin and shows in both runs. What I could not check: the mobile thread header, since I had no device.

Bug: subagent threads show the remote parent their parent was delegated from

This was written with Claude Opus 5.5 in Claude Code, driven from T3 Code.

[macroscopeapp]

Approvability

Verdict: Approved at eaea553

Macroscope's review found this PR approvable — Subagent children no longer inherit their parent's remote-delegation metadata, preventing misleading remote-parent relationships. Their actual local parent lineage remains intact, keeping the change narrowly scoped.

^{You can add or adjust custom eligibility rules. Learn more.}

[coderabbitai]

No actionable comments were generated in the recent review.

Walkthrough

The subagent child projection no longer inherits the parent thread’s delegatedFrom field. The test fixture sets that field on the parent and verifies it is absent from the child.

Changes: Subagent child projection

Layer / File(s)	Summary
Child delegation reset packages/provider-core/src/server/subagentProjection.ts, apps/server/src/orchestration-v2/SubagentProjection.test.ts	makeSubagentChildThread omits the parent’s delegatedFrom field. The test checks that it is undefined on the child and retains checks for snooze and title-job resets.

Estimated code review effort: 2 (Simple) | ~5 minutes

Change: Bug fix

Suggested reviewers: juliusmarminge

Merge Risk: Minimal · up to dccfa

Subagent threads will no longer show the remote parent that their parent was delegated from. The change is small, covered by a targeted test, and easy to revert, so merge risk is minimal.

Pre-merge checks: 4

Check name	Status	Explanation
Title check		The title names the main change: subagent threads no longer inherit the remote parent from the delegated parent thread. It follows the conventional commit format and matches the code change that drops…
Description check		The description follows the template. It states the problem with reproduction context and the client symptoms, and it explains the change. It gives scope and a rationale for no linked issue, and it gi…
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

Full details: Title check

Explanation

The title names the main change: subagent threads no longer inherit the remote parent from the delegated parent thread. It follows the conventional commit format and matches the code change that drops delegatedFrom in makeSubagentChildThread.

Full details: Description check

Explanation

The description follows the template. It states the problem with reproduction context and the client symptoms, and it explains the change. It gives scope and a rationale for no linked issue, and it gives focused test results plus a manual check with before/after evidence. It notes what was not checked (mobile header). The template's Scope section asks for a linked issue or a reason for none; the author gives a reason, and the description cites related prior PRs. The description also has an opening conventional-commit style title line, which the template recommends but the body does not need to repeat. Overall it is mostly complete.

Finishing Touches

Generate unit tests (beta)

• Create a new PR

• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

Recent review info

Run configuration

• Source mode: Auto
• Repository: pingdotgg/t3code
• Branch: main
• File: .coderabbit.config.ts
• Commit: ab2bf94
• Layers: Repository TS config
• Review profile: CHILL
• Plan: Advanced
• Run ID: 359febee-f2df-4931-bd5c-d1afddba767a

Commits

Reviewing files that changed from the base of the PR and between eaea553 and dccfafb.

Files selected for processing: 1

• packages/provider-core/src/server/subagentProjection.ts

Included review availability: This review used your included allowance. Your plan provides up to 10 included reviews per hour; 8 remain after this review.

[juliusmarminge]

Evidence

Seed a remotely delegated parent through the receiving-side linked-client MCP launch, replay one general native OpenCode task, then open its child and inspect Lineage. Real web app on both commits; fresh synthetic state, Chromium, light theme, 1440×900 CSS pixels. Base shows two parent rows; head keeps only the local parent. The linked-origin header badge remains on both.

Before	After
ab2bf940f6	dccfafb07e

Seed/replay driver · Reproduction instructions

Scope: receiving-side remote delegation and native child projection were replayed; live cross-environment forwarding, Grok execution, and mobile were not verified.

Not shown:

• Mobile linked-origin subtitle was not exercised in a native client.
• Live cross-environment delegate_task forwarding and Grok execution were not exercised; the driver reproduced the receiving-side launch and replayed a native OpenCode task lifecycle.