Session Miser

Session-Miser — Session-Level Cost Optimization

Core Principle

Use the cheapest model that can do the job well. Opus for thinking, Sonnet for doing, Haiku for fetching.

For per-call routing, pricing data, and API-level optimization, see the token-miser skill. This skill covers session-level decisions only: which model to start on, when to switch, and what to delegate.

Planning Phase Exemption

During the planning phase (before ExitPlanMode), use Opus for all subagents:

• project-management planning — Explore/Plan agents building the work queue
• /plan mode — implementation design

Once ExitPlanMode is called, normal routing resumes.

Session Start Assessment

At session start, assess the work and recommend:

| Work Profile | Recommendation | |---|---| | Architecture, design, complex planning | Stay on Opus | | Debugging root cause analysis | Stay on Opus | | Mixed planning + execution | Stay on Opus, DELEGATE mechanical tasks to subagents | | Primarily code edits, file changes, deploys | Suggest /model sonnet | | Bulk operations, config changes, formatting | Suggest /model sonnet |

When to Switch Models Mid-Session

| Signal | Action | |---|---| | Planning phase complete, entering execution | Suggest /model sonnet | | Hit unexpected architectural decision | Switch back to Opus for that decision | | 30+ minutes of file edits on Opus | Suggest /model sonnet | | Debugging shifts from "apply known fix" to "investigate root cause" | Switch to Opus | | Cost climbing fast with no complex reasoning | Suggest delegation or model switch |

Delegation Rules

ALWAYS delegate (automatic, don't ask):

• File exploration → Explore agent (haiku)
• Git status, diff, log → haiku subagent
• Searching codebase → haiku subagent
• Running bash for status checks → haiku subagent

SUGGEST delegating (mention to user):

• Bulk file edits across repos → sonnet subagent
• Running test suites → haiku subagent
• Documentation generation → sonnet subagent
• Config file updates → sonnet subagent

NEVER delegate:

• Active user discussion topics
• Security-sensitive operations
• Complex multi-step reasoning chains

Effort Level Guide

| Effort | Use For | Relative Cost | |---|---|---| | high | Complex problems, architecture, security | 1x | | medium | Most coding, debugging, research | ~0.7x | | low | Simple edits, formatting, git ops | ~0.4x |

Prefer opus:low for simple tasks over switching to Sonnet entirely — preserves Opus quality for unexpected complexity.

Cost Tracking

Check session cost via hydra-pulse / session-snitch:

# If hydra-pulse CLI available
hydra-pulse stats

If cost climbing fast: delegate more, switch model, or reduce effort level.

Anti-Patterns

• Using Opus to read a file and report contents (haiku job)
• Using Opus for git status (haiku job)
• Using Opus for JSON/YAML formatting (sonnet:low)
• Staying on Opus for 30+ minutes of mechanical edits
• Switching to Haiku for anything requiring judgment

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: scoobydont-666
• Source: scoobydont-666/shared-claude-skills
• License: MIT

Install and usage instructions live in the source repository linked above.