fix(mobile): allow starting a task with only an image

[Claudesaul]

Problem

Sharing a photo to T3 Code on iOS opens the new-task composer with the image attached, but Start task stays disabled until you type something.

Change

New tasks required text in four places: canStart and handleStart in NewTaskDraftScreen, buildPendingTaskMessage, and isQueuedThreadCreationSendable. The last one meant that even with the button enabled, the task sat in the outbox and was never sent. All four now accept text or an attachment, the same as follow-up messages and web already do.

Scope and approval

Small fix for an obvious bug. Follow-ups already allow image-only messages, and the server accepts a turn with empty text.

Verification

• Added a thread-outbox.test.ts case: image with no text is sendable, whitespace-only text isn't. It fails without the fix.
• vp test run on the outbox and pending-task tests (77 passed); mobile typecheck clean.
• iOS 27 simulator: Photos → Share → T3 Code. Before, Start task was disabled. After, the thread is created and the agent replies.
• Android not checked; it uses the same code.

Before	After	Sent

Model: Claude Opus 5.5; harness: Claude Code.

[macroscopeapp]

Approvability

Verdict: Approved at 234e740

Macroscope's review found this PR approvable — This is a narrowly scoped mobile bug fix that lets existing attachment payloads start a task without requiring text, while preserving all existing validation and upload safeguards. The accompanying test covers both attachment-only acceptance and whitespace-only rejection.

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[coderabbitai]

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Review skipped

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📥 Commits

Reviewing files that changed from the base of the PR and between 234e740 and 6af4488.

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📥 Commits

Reviewing files that changed from the base of the PR and between 3b6af0b and 234e740.

📒 Files selected for processing (4)

• apps/mobile/src/features/threads/NewTaskDraftScreen.tsx
• apps/mobile/src/features/threads/new-task-flow-provider.tsx
• apps/mobile/src/state/thread-outbox-model.ts
• apps/mobile/src/state/thread-outbox.test.ts

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📝 Walkthrough

Walkthrough

Task drafts with attachments can now be submitted and queued without prompt text. Model selection and other existing submission requirements remain in place.

Changes

Attachment-only task creation

Layer / File(s)	Summary
Allow attachments without prompt text apps/mobile/src/features/threads/NewTaskDraftScreen.tsx, apps/mobile/src/features/threads/new-task-flow-provider.tsx, apps/mobile/src/state/thread-outbox-model.ts, apps/mobile/src/state/thread-outbox.test.ts	The task screen, pending-message builder, and queued-send check accept attachments when prompt text is empty. Tests cover whitespace-only text and an image attachment.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Suggested reviewers: juliusmarminge

Merge Risk

Merge Risk: ⚪ Minimal · up to 234e7

Attachment-only task creation carries its attachment through the queued and receiving paths; no actionable merge risk is established.

Security Architecture Review

Security architecture risk: ⚪ Minimal · up to 234e7

The change lets an attachment satisfy the task-content requirement without granting additional permissions or changing how attachments reach the agent. Existing authorization, upload, workspace, and delivery controls remain in place. No material security risk was found introduced or worsened by this change.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — The newly reachable case is user-supplied attachment content without accompanying text, delivered to the selected environment and project using existing model, runtime, and workspace choices. The inspected delta does not grant additional agent authority or introduce a new service destination compared with text-plus-attachment creation.

Trust Boundaries and Controls

• observed — The existing upload path rechecks operation access and verifies the environment before reusing uploaded references. Server launch intake validates attachment limits, requires a thread identity for pending uploads, and claims attachments against that thread before launch. Empty text does not skip these controls.

Resilience and Maintainability Implications

• observed — The existing transition retains uploaded references through revision-checked persistence before launch, checks concurrent edits and editor ownership, and records delivery before removing the queued row and releasing resources. Server launch reads command receipts, uses a stable initial-message command identity, and reserves preparation to limit duplicate setup. Intake releases unused attachment claims after success and releases claims on errors established to precede acceptance rather than treating every error as rollback-safe.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description check		The description includes all required sections. It clearly states the problem, explains the changes across the affected components, gives an applicable scope rationale, and documents focused tests, ma…
Title check		The title is concise, uses the required conventional format, and accurately describes the main change: allowing mobile tasks to start with only an image.
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.

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[alhss]

Would be helpful