[andrewcai8]

When T3 Code resumes a turn on its own, it always sent Continue where you left off.. Users who drive agents through a skill had no way to start that message with one, such as /poteto-mode. After a usage-limit account switch the agent also got no hint that it had moved, so it sometimes held back on subagents or waited for a reset.

How

• New server setting continuationPrompt (trimmed, non-empty). It defaults to Continue where you left off., so nothing changes for anyone who leaves it alone. It is a shared setting like Auto-resume limited threads, so saving it from one client writes it to every connected environment.
• accountSwitchContinuation(prompt) appends one note to switch continuations only: "Your previous account hit its usage limit, so this chat moved to another account with room. Subagents and new chats are also routed to accounts with room, so keep working and delegating as usual." The note does not name a provider.
• The prompt is always the first text in the message, so a slash-command skill still parses as one.
• Command and message ids and idempotency keys are unchanged.

Every source covered

Source	Before	Now
UsageLimitRecoveryWorker reset resume (limit-resume:)	fixed text	prompt
UsageLimitRecoveryWorker account switch (limit-switch:)	fixed text	prompt + account note
RestartContinuation after a restart or update	fixed text, with any cancelled-work note before it	prompt, with any cancelled-work note after it
Cloud box switch (ProviderAccountSwitch, account-switch:)	fixed text	prompt + account note. The host sends its own continuationPrompt in GuestAccountSwitchInput, and the box falls back to its own setting. Older boxes drop the unknown field and keep the old text.
Web Resume button (ChatView)	fixed text	the environment's prompt

Behavior change for default users: when a restart cancelled background work, the message used to be <note>\n\nContinue where you left off.. It is now Continue where you left off.\n\n<note>. The order is flipped so a configured skill prefix stays first.

Not changed:

• The settled restart note sends no continue prompt, as before.
• Mobile has no Resume button that sends text. Mobile settings get no text field: the setting syncs to every environment from web or desktop, and a draft-and-commit text row on the multi-environment Thread behavior screen is more UI than a set-once preference earns.
• Project-scoped overrides are left out, so the setting is global.
• No user-doc sentence describes the message text, so the docs are unchanged.

UI

Settings, General, below the usage-limit toggles. A Continuation message text field with a reset button, a settings-search entry, and an entry in restore defaults. Clearing the field restores the default. No screenshots were taken because this run did no browser verification.

Tests

• runtimeLayer.test.ts "usage-limit account switch". With the setting /poteto-mode Continue where you left off., a switch sends the prompt plus the note, and a reset resume sends the prompt alone.
• RestartContinuation.test.ts. A configured prompt comes first, with no account note, including when a cancelled-work note is present. The default text is unchanged.
• ProviderAccountSwitch.test.ts. The box uses the host-sent prompt plus the note, and falls back to the default plus the note when the host sends none.
• sharedSettings.test.ts. continuationPrompt is a shared key.
• Mutation check: moving the note ahead of the prompt fails three of these tests.
• Ran tsc-rs --noEmit for contracts, client-runtime, server, web, and mobile. Ran targeted vp lint.

🤖 Generated with Claude Code

[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

ℹ️ The exact PR base did not have a successful artifact. Baseline uses the latest successful main measurement shown below.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	5.0 KiB	5.0 KiB	0 B (0.0%)	6.8 KiB	✅
Codex	Thread snapshot wire	3.8 KiB	3.8 KiB	0 B (0.0%)	4.9 KiB	✅
Codex	Live turn WebSocket wire	1.2 KiB	1.2 KiB	0 B (0.0%)	2.0 KiB	✅
Codex	Live turn WebSocket decoded	20.9 KiB	20.9 KiB	0 B (0.0%)	29.3 KiB	✅
Codex	Live turn messages	2	2	0 (0.0%)	8	✅
Claude	Total thread wire	5.0 KiB	5.0 KiB	+7 B (+0.1%)	6.8 KiB	✅
Claude	Thread snapshot wire	3.8 KiB	3.8 KiB	0 B (0.0%)	4.9 KiB	✅
Claude	Live turn WebSocket wire	1.2 KiB	1.2 KiB	+7 B (+0.6%)	2.0 KiB	✅
Claude	Live turn WebSocket decoded	21.2 KiB	21.2 KiB	0 B (0.0%)	29.3 KiB	✅
Claude	Live turn messages	2	2	0 (0.0%)	8	✅

Baseline: acc526d · PR result: 88d0dd5 · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 108.5 KiB
• Claude decoded thread snapshot: 108.8 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.