Mode

/mode — LLM Routing Switch

Manage delegation across a multi-LLM setup. The pattern: Claude orchestrates, judges, reviews, and surgically fixes; cheaper or specialized CLIs handle the heavy lifting.

Layer	Typical CLI	Strength
Heavy reading	Antigravity CLI (agy)	Large context window, fast cold reads. Replaces the Gemini CLI on consumer plans as of 2026-06-18; enterprise plans may still ship gemini.
Heavy writing	Codex CLI	High-throughput code generation
Surgical web search	Perplexity API (or others)	Live docs, breaking changes

Other skills in this collection read .claude/llm-mode.json to decide whether to delegate. When mode is single, every skill runs natively in Claude.

Route by argument

Parse the argument after /mode:

• No args → show status
• multi → switch to multi
• single → switch to single
• stats → show delegation log
• reset → reset to defaults

Show status (default)

Read .claude/llm-mode.json and display:

## LLM Mode: <MULTI / SINGLE>

### Delegation targets (in multi mode)
  READING (Antigravity CLI / agy):  [available / not found]
  WRITING (Codex CLI):              [available / not found]
  WEB SEARCH (Perplexity):          [key set / key missing]

### Delegation stats
  Total:     N successful delegations
  Failed:    N (X% failure rate)
  Last:      YYYY-MM-DD HH:MM via <skill>

Switch with: /mode multi  or  /mode single
Full log:    /mode stats

To populate the display:

1. Read .claude/llm-mode.json for mode and stats.
2. Check agy --version for Antigravity CLI. Fall back to gemini --version for enterprise plans still on the legacy binary.
3. Check codex --version for Codex CLI.
4. Check $PERPLEXITY_API_KEY (or your provider's env var) for web search.
5. Count entries in .claude/delegation.log for the totals.

If .claude/llm-mode.json doesn't exist, show Mode: SINGLE (default — no config file yet).

Switch to multi

1. Verify the Google delegate CLI is installed and authenticated. Prefer Antigravity CLI (agy); fall back to the legacy gemini binary for enterprise plans.

   # Antigravity CLI (consumer + new enterprise).
   # The `</dev/null` redirect is mandatory: `agy -p "..."` deadlocks waiting for
   # TTY input even when a prompt arg is supplied.
   agy --version 2>/dev/null \
     || gemini --version 2>/dev/null
   
   agy -p "Reply with exactly: OK" </dev/null 2>/dev/null \
     || gemini -p "Reply with exactly: OK" -o text 2>/dev/null
   

   If the auth check fails, abort with installation/auth instructions. For agy, the install command is curl -fsSL https://antigravity.google/cli/install.sh | bash.

2. Update .claude/llm-mode.json: set mode to "multi", update updated_at to the current ISO timestamp.

3. Append to .claude/delegation.log:

   YYYY-MM-DDTHH:MM:SSZ | mode | ok | 0s | Switched to multi-LLM mode
   

4. Check Codex CLI and Perplexity availability non-blockingly. Report each as "available" or "not found / key missing" in the confirmation.

Switch to single

1. Update .claude/llm-mode.json: set mode to "single", refresh updated_at.
2. Log: ... | mode | ok | 0s | Switched to single-LLM mode.
3. Confirm: "Switched to single-LLM mode. All skills using Claude natively."

Show delegation log

Read .claude/delegation.log and show the last 20 entries plus summary stats: total, failure rate, average duration on success, most-delegated skill.

Reset

1. Write a fresh .claude/llm-mode.json with defaults (single mode, zeroed stats).
2. Clear .claude/delegation.log (keep any header comments).
3. Confirm.

Delegation logging protocol

Other skills that delegate should follow this protocol:

After a successful delegation:

echo "$(date -u +%Y-%m-%dT%H:%M:%SZ) | <skill> | ok | <duration>s | <notes>" \
  >> .claude/delegation.log

Also increment stats.delegations_total and update stats.last_delegation in .claude/llm-mode.json.

On failure:

echo "$(date -u +%Y-%m-%dT%H:%M:%SZ) | <skill> | fail | <duration>s | <reason>" \
  >> .claude/delegation.log

Increment stats.delegations_failed.

Schema for .claude/llm-mode.json

{
  "mode": "single",
  "updated_at": "2026-06-04T00:00:00Z",
  "stats": {
    "delegations_total": 0,
    "delegations_failed": 0,
    "last_delegation": null
  }
}

Known gotchas

• Multi mode without authenticated CLIs silently falls back to Claude. That can mask a real problem — the user thinks they're saving tokens but every delegation is failing. The status display surfaces both auth state and recent failure rate for this reason.
• The log file grows unboundedly. Rotate or truncate it before it crosses ~10k lines or the stats view gets slow.
• Mode is per-project. Each project has its own .claude/llm-mode.json. Setting it in one project does not affect siblings.
• agy -p "<prompt>" requires </dev/null. Without the stdin redirect, Antigravity CLI waits on a TTY even when a prompt arg is given. The probe in "Switch to multi" uses the canonical agy -p "..." </dev/null form; mirror it in every other call site.

Anti-patterns

• Flipping to multi mode for a quick win, then forgetting to switch back when the delegated CLIs go stale. Add the status check to a /brief-style routine.
• Trusting delegations_total as a token-savings proxy. The skills that delegate know their own savings; the mode skill just tracks counts.

Validated patterns

• Logging both success and failure (rather than just success) keeps the failure-rate metric honest. A 30% failure rate is a signal that the auth or model config needs attention.

Self-improvement

This skill ships with a lightweight feedback loop. Adopt or ignore — the skill works without it.

Trigger a review when:

• The status display is wrong about CLI availability (the detection command needs updating).
• A new external CLI joins the routing pattern.
• learnings.md crosses ~100 bullets (consolidation time).
• The skill mis-triggers or fails to trigger.

Consolidation pass (5–10 min, weekly or threshold-driven):

• Each entry gets one fate: apply, capture, or dismiss.
• Apply = merge into Known gotchas / Anti-patterns / Validated patterns.
• Capture = leave in learnings.md for now.
• Dismiss = delete.
• Bump last-consolidated: in frontmatter.