cost-optimizer

A reviewer for Claude API usage that looks for ways to reduce cost. It checks patterns related to caching, model choice, batch processing, streaming, output limits, and context size.

In plain words
What is it for?
Use it to review API usage, find cost-saving opportunities, plan batch jobs, and track improvements over time.
Why use it?
It points out changes that may lower API spending when prompts or usage patterns are inefficient.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/apiliumcode/mayros/cost-optimizer
Any agent
npx skills add ApiliumCode/mayros --skill cost-optimizer
Clone the repo
git clone --depth 1 https://github.com/ApiliumCode/mayros

Made for: Claude Code, Codex.

Per session 13 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 220 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00013 $0.00220
Opus 5 $0.00006 $0.00110
Sonnet 5 $0.00003 $0.00044
Haiku 4.5 $0.00001 $0.00022

Measured 2d ago against content hash 730926adc692, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cost-optimizer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

The scan reads SKILL.md. This mod also ships 3 executable files (skill.test.ts, skill.ts, types.ts), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/official/cost-optimizer/SKILL.md · 31 lines

What it actually says

cost-optimizer

Detect cost optimization opportunities for Claude API usage by analyzing usage patterns and recommending pricing-aware strategies.

When to Use

Use when analyzing API usage costs, planning batch processing workflows, or optimizing prompt engineering for cost efficiency. The skill evaluates 6 optimization rules: prompt caching, model downgrade, Batch API, streaming, output limits, and context trimming.

Instructions

  1. Recall previous cost analysis with skill_memory_context using predicate cost:opportunity
  2. The skill scans usage data for patterns indicating optimization potential
  3. Each detected opportunity includes an estimated savings percentage
  4. Review recommendations and apply the most impactful changes first
  5. Re-run periodically to track cost reduction progress over time
Files

What ships with it

9 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 31 lines · 13 tokens per session scan A 730926adc692

Subscribe to this mod's changes

cost-optimizer is a skill published in the GitHub repository ApiliumCode/mayros (12 stars, last pushed 1mo ago), licensed MIT. It adds 13 tokens to every session and 220 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.