feat: implement /loop command with fixed and dynamic scheduling

[khaledmoayad]

Summary

Implements the /loop skill with four scheduling modes and enables the cron infrastructure needed for it to work in the open build.

The Bun constant-folding problem

While testing, we discovered that Bun's constant folder evaluates feature('AGENT_TRIGGERS') at bundle time through the bun:bundle shim — and the folded value is cached from a previous build. This means flipping the flag to true in build.ts doesn't help: the require() blocks inside if (feature('AGENT_TRIGGERS')) still compile to if (false) {} dead code, so cron tools, useScheduledTasks, and loop skill registration are all silently dropped from the bundle.

This is why we need to remove the guards rather than just flip the flag — and why #633 alone won't be enough to activate /loop.

Changes

Loop skill (loop.ts, loop.test.ts):

• Four modes: fixed-interval with prompt, fixed-interval maintenance, dynamic self-pacing, dynamic maintenance (bare /loop)
• Interval parsing accepts leading tokens, trailing "every" clauses, and human-readable units
• Maintenance mode reads .claude/loop.md or ~/.claude/loop.md, falls back to built-in prompt

Infra (needed due to the Bun bundling issue above):

• tools.ts: cron tools always registered; isEnabled gates visibility at runtime
• REPL.tsx: useScheduledTasks always mounted via unconditional import
• index.ts: registerLoopSkill via static import, called unconditionally
• prompt.ts: isKairosCronEnabled() returns true for non-ant builds without consulting the feature flag

Test plan

• bun test src/skills/bundled/loop.test.ts — all four modes pass
• node dist/cli.mjs — /loop 1m say hi schedules, fires, and repeats
• bare /loop enters dynamic maintenance mode and self-reschedules

[Copilot]

Pull request overview

Implements a new /loop bundled skill that can either schedule fixed recurring cron runs or dynamically self-reschedule within a session, and makes cron tooling/scheduler available in open builds by default (with an env var kill switch).

Changes:

• Added /loop skill prompt generation supporting fixed-interval and dynamic self-pacing modes, including maintenance-mode behavior.
• Enabled cron tools and /loop registration without the feature('AGENT_TRIGGERS') compile-time guard; adjusted the cron runtime gate to default-on for non-ant builds with CLAUDE_CODE_DISABLE_CRON override.
• Updated the REPL to always mount the scheduled-task scheduler hook.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/tools/ScheduleCronTool/prompt.ts	Changes cron runtime gating to default-enable for non-ant builds, keeping a local env override and internal GrowthBook kill switch.
src/tools.ts	Registers CronCreate/Delete/List unconditionally so cron tooling is always present (runtime-gated via isEnabled).
src/skills/bundled/loop.ts	Replaces the prior fixed-interval-only /loop prompt with fixed + dynamic + maintenance-mode prompt generation and interval parsing.
src/skills/bundled/loop.test.ts	Adds Bun tests covering the four /loop modes.
src/skills/bundled/index.ts	Registers /loop skill unconditionally at startup.
src/screens/REPL.tsx	Always mounts useScheduledTasks, allowing cron + /loop session-only runs in all builds (runtime gated inside the hook).

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[khaledmoayad]

@kevincodex1 @Vasanthdev2004 can I get a review on this?

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

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[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

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[Copilot]

isKairosCronEnabled() no longer uses feature('AGENT_TRIGGERS'), so the feature import from bun:bundle in this file is now unused and will likely fail lint/typecheck. Remove the unused import (and any related dead-code-elimination comments if no longer applicable) to keep the module clean.

[Copilot]

The fixed-mode instructions tell the model to call CronCreate but don’t name the required input fields. CronCreate’s schema expects cron and prompt, so please explicitly specify those parameter names here to avoid tool calls failing due to wrong keys.

Suggested change

	- the recurring cron expression
	- the effective prompt body above
	- cron: the recurring cron expression
	- prompt: the effective prompt body above

[Copilot]

In dynamic mode, the CronCreate scheduling instructions also omit the expected input keys (cron, prompt). Please make the parameter names explicit so the one-shot follow-up run is scheduled reliably and stays in dynamic mode.

Suggested change

	- Pin the cron expression to a specific future local-time minute that matches the chosen delay.
	- Set the scheduled prompt to this exact text so the next iteration stays in dynamic mode:
	- Set cron to a specific future local-time minute that matches the chosen delay.
	- Set prompt to this exact text so the next iteration stays in dynamic mode:

[Vasanthdev2004]

Review: /loop command with fixed and dynamic scheduling

Thanks for this — the four-mode /loop design (fixed-prompt, fixed-maintenance, dynamic-prompt, dynamic-maintenance) is well thought out, and the interval parsing is clean. The Bun constant-folding problem is a genuine gotcha and the workaround (removing build-time guards so the code gets bundled) makes sense.

CI is green ✅. Tests cover all four modes plus edge cases like check every PR not matching the trailing every clause — nice.

That said, the partial removal of feature('AGENT_TRIGGERS') guards creates an inconsistency that could break cron in non-interactive mode.

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🔴 Blocker: feature('AGENT_TRIGGERS') guards removed from 4 files but left in 2 others

This PR removes the feature('AGENT_TRIGGERS') guard from:

• ✅ src/tools.ts — cron tools always registered
• ✅ src/screens/REPL.tsx — useScheduledTasks always mounted
• ✅ src/skills/bundled/index.ts — registerLoopSkill always called
• ✅ src/tools/ScheduleCronTool/prompt.ts — isKairosCronEnabled() returns true for non-ant builds

But leaves the guard in:

• ❌ src/cli/print.ts lines 365–371 — cronSchedulerModule, cronJitterConfigModule, cronGate are all null when AGENT_TRIGGERS is off
• ❌ src/cli/print.ts line 2705 — cron scheduler is only created when feature('AGENT_TRIGGERS') is true AND isKairosCronEnabled() — in open builds, both the module-level requires are dead AND the scheduler init block is skipped
• ❌ src/constants/tools.ts line 85 — cron tool names are only added to DISALLOWED_ASYNC_TOOLS when AGENT_TRIGGERS is on

Result: In the open build after this PR merges:

Scenario	REPL (interactive)	-p / non-interactive
Cron tools registered	✅ (always)	✅ (always)
isKairosCronEnabled()	✅ returns true	✅ returns true
Cron scheduler running	✅ (useScheduledTasks mounts)	❌ dead — feature('AGENT_TRIGGERS') is false at bundle time, so cronSchedulerModule is null and the scheduler is never created
/loop in -p mode	N/A	❌ broken — tools exist, skill is registered, but no scheduler fires them

The REPL interactive path works fine because useScheduledTasks has its own isKairosCronEnabled() check and creates the scheduler independently. But the non-interactive path (print.ts) is gated by a build-time constant that still evaluates to false.

Fix: Also remove the feature('AGENT_TRIGGERS') guards from src/cli/print.ts (lines 365–371, 2705) and src/constants/tools.ts (line 85), matching the pattern used in the other files. Or — if the intent is to only support /loop in interactive REPL mode for now — document that explicitly so it's not a surprise.

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🟡 Non-blocking: feature('AGENT_TRIGGERS') is still referenced in PR description but now dead in 4/6 files

The PR body explains the Bun constant-folding problem clearly. But after the partial guard removal, the term AGENT_TRIGGERS is a bit of a zombie — still referenced in code comments and print.ts/constants/tools.ts guards, but no longer the actual gate for the open build. Worth updating the PR description or adding a code comment summarizing the new gating strategy:

Open builds: isKairosCronEnabled() always returns true (unless CLAUDE_CODE_DISABLE_CRON=1).
Ant builds: isKairosCronEnabled() defers to GrowthBook tengu_kairos_cron.
Build-time feature('AGENT_TRIGGERS') is no longer the cron gate — it's a bundle-time constant that Bun folds. The runtime gate is isKairosCronEnabled().

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🟢 Loop skill implementation — clean

• parseLoopArgs() is well-structured with clear priority: bare interval → leading interval → trailing every clause → dynamic.
• parseTrailingEveryClause correctly avoids matching check every PR because PR isn't a time unit — good edge case coverage.
• normalizeIntervalUnit supports both short and long forms — nice UX.
• buildFixedPrompt and buildDynamicPrompt both use --- BEGIN/END PROMPT --- delimiters for unambiguous prompt extraction.
• Dynamic mode rescheduling via recurring: false + self-referencing /loop prompt is an elegant design.
• Maintenance mode with .claude/loop.md / ~/.claude/loop.md fallback + built-in prompt is practical.
• The isEnabled: isKairosCronEnabled delegation on the skill is correct — it gates visibility at the skill level, matching the tool pattern.

🟢 REPL.tsx change — safe

useScheduledTasks has an internal if (!isKairosCronEnabled()) return guard at the top of its useEffect. Unconditionally mounting it is rules-of-hooks compliant and just defers the gate to runtime. This is exactly the pattern described in the old comment — just without the build-time dead-code wrapper.

🟢 Tests — thorough

125 lines covering all 4 modes, edge cases (check every PR), human-readable units, and prompt delimiter presence. Good coverage for a prompt-generation skill.

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Verdict: Needs changes 🔧

One blocker: the partial AGENT_TRIGGERS guard removal leaves cron non-functional in -p / non-interactive mode. The fix is to also remove the guards from print.ts and constants/tools.ts, or explicitly document that /loop is REPL-only for now.

Once the guard removal is consistent across all 6 files (or the limitation is documented), this is approve-ready. The /loop skill implementation itself is solid.

[khaledmoayad]

@Vasanthdev2004 great catch — you're right, the guard removal was incomplete.

Fixed in 6cfb665:

• src/cli/print.ts: cronSchedulerModule, cronJitterConfigModule, and cronGate are now unconditional requires. The scheduler init block drops the feature('AGENT_TRIGGERS') check and delegates entirely to cronGate.isKairosCronEnabled() (which returns true for non-ant builds unless CLAUDE_CODE_DISABLE_CRON=1).
• src/constants/tools.ts: Cron tool names are always included in IN_PROCESS_TEAMMATE_ALLOWED_TOOLS — no more feature-gated spread.

/loop should now work correctly in -p / non-interactive mode as well as the REPL.

[Vasanthdev2004]

Re-review after requested changes

Reviewed on head 6cfb665. CI green ✅.

Both blockers from the previous review are now fixed:

✅ src/cli/print.ts — guards removed

• cronSchedulerModule, cronJitterConfigModule, cronGate are now unconditional require()s — no more feature('AGENT_TRIGGERS') ternary wrappers
• runHeadlessStreaming scheduler init: if (cronGate.isKairosCronEnabled()) — clean single-gate, no more feature('AGENT_TRIGGERS') && prefix
• Optional chaining removed from cronJitterConfigModule?.getCronJitterConfig → cronJitterConfigModule.getCronJitterConfig and cronGate?.isKairosCronEnabled() → cronGate.isKairosCronEnabled() — correct since the modules are always loaded now

✅ src/constants/tools.ts — cron tools always included

CRON_CREATE_TOOL_NAME, CRON_DELETE_TOOL_NAME, CRON_LIST_TOOL_NAME are now unconditionally spread into IN_PROCESS_TEAMMATE_ALLOWED_TOOLS. No more feature('AGENT_TRIGGERS') conditional.

✅ isKairosCronEnabled() — clean two-path gate

The updated logic is simple and correct:

• CLAUDE_CODE_DISABLE_CRON=1 → always false (local kill switch)
• USER_TYPE !== 'ant' → always true (open builds)
• Otherwise → defer to GrowthBook tengu_kairos_cron with true default

This is the right stratification — open builds get cron unconditionally, Anthropic-internal builds keep the fleet-wide kill switch.

Result: consistent guard removal across all 6 files

File	Guard removed?
src/tools.ts	✅ (previous commit)
src/screens/REPL.tsx	✅ (previous commit)
src/skills/bundled/index.ts	✅ (previous commit)
src/tools/ScheduleCronTool/prompt.ts	✅ (previous commit)
src/cli/print.ts	✅ fixed in this commit
src/constants/tools.ts	✅ fixed in this commit

Cron now works in both REPL and -p/non-interactive mode for open builds. The /loop skill implementation remains solid.

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Verdict: Approve-ready ✅

Clean fix, all blockers resolved. The guard removal is now consistent and the runtime gating (isKairosCronEnabled()) is the single source of truth.

[khaledmoayad]

@kevincodex1 @euxaristia would appreciate a review on this if you have a moment!

[kevincodex1]

lgtm thanks bro!

[Flo5k5]

Nice work on the loop rewrite — the 4-mode parsing with proper code-level extraction is a solid improvement over the "let the LLM figure it out" approach, and the maintenance mode with .claude/loop.md is a great touch.

Re: your latest comment — agreed that removing the guards and using isKairosCronEnabled() as the sole runtime gate is the cleaner long-term pattern. Since #657 fixes the build system foundation, I'll land it first so you have a clean base. #633 will become redundant once #621 lands (same guards, different strategy), so I'll close it at that point.

Minor suggestion: in isKairosCronEnabled(), the process.env.USER_TYPE !== 'ant' check works correctly for the open build but relies on an implicit convention. A one-line comment noting that USER_TYPE is never 'ant' in open builds would help future readers.

Tests are thorough — the "check every PR" edge case is a nice catch. LGTM.