llm-router

llm-router is a skill for Claude Code from curiositech/some_claude_skills. It costs 121 tokens per session (1,820 once invoked), scanned A, original, MIT.

A decision guide for choosing an AI language model and provider for each task, based on the task's difficulty, quality needs, and cost limits.

In plain words
What is it for?
It supports model selection, cost-aware routing in multi-step agent workflows, and try-cheap-first systems.
Why use it?
It helps avoid using an expensive model for simple work while still escalating difficult tasks when a cheaper model is not good enough.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: positional $N argument.

Part of the llm-router plugin — 1 skill shipped together

Good fit It supports model selection, cost-aware routing in multi-step agent workflows, and try-cheap-first systems.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/curiositech/some_claude_skills/llm-router
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.

Any agent
npx skills add curiositech/some_claude_skills --skill llm-router
Clone the repo
git clone --depth 1 https://github.com/curiositech/some_claude_skills

Made for: Claude Code.

Or install llm-router, the plugin that ships this one along with the rest of its 1 skill.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for llm-router

README.md
[![agentmods](https://agentmods.dev/badge/skills/curiositech/some_claude_skills/llm-router/github.svg)](https://agentmods.dev/skills/curiositech/some_claude_skills/llm-router)
Your own site
<a href="https://agentmods.dev/skills/curiositech/some_claude_skills/llm-router"><img src="https://agentmods.dev/badge/skills/curiositech/some_claude_skills/llm-router/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for llm-router

Your own site · 80×15
<a href="https://agentmods.dev/skills/curiositech/some_claude_skills/llm-router"><img src="https://agentmods.dev/badge/skills/curiositech/some_claude_skills/llm-router.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 121 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,820 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 5.1 $0.00121 $0.01820
Opus 5 $0.00060 $0.00910
Sonnet 5 $0.00024 $0.00364
Haiku 4.5 $0.00012 $0.00182

Measured 7d ago against content hash fc1d57acf95b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

llm-router 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 7d ago.

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.

.claude/skills/llm-router/SKILL.md · 170 lines

How it starts

The opening of the file, as written. The whole thing — 170 lines — stays where its author put it; the contents beside it link to each section on GitHub.

LLM Router

Selects the optimal LLM model for each task. The single biggest cost lever in multi-agent systems — intelligent routing saves 45-85% while maintaining 95%+ of top-model quality.


When to Use

Use for:

  • Deciding which model to call for a specific task
  • Assigning models to DAG nodes in agent workflows
  • Optimizing LLM API costs across a system
  • Building cascading try-cheap-first patterns

NOT for:

  • Prompt engineering (use prompt-engineer)
  • Model fine-tuning or training
  • Comparing model architectures (academic research)

Routing Decision Tree

flowchart TD
  A{Task type?} -->|Classify / validate / format / extract| T1["Tier 1: Haiku, GPT-4o-mini (~$0.001)"]
  A -->|Write / implement / review / synthesize| T2["Tier 2: Sonnet, GPT-4o (~$0.01)"]
  A -->|Reason / architect / judge / decompose| T3["Tier 3: Opus, o1 (~$0.10)"]
  
  T1 --> Q1{Quality sufficient?}
  Q1 -->|Yes| Done1[Use cheap model]
  Q1 -->|No| T2
  
  T2 --> Q2{Quality sufficient?}
  Q2 -->|Yes| Done2[Use balanced model]
  Q2 -->|No| T3

Tier Assignment Table

Task Type Tier Models Cost/Call Why This Tier
Classify input type 1 Haiku, GPT-4o-mini ~$0.001 Deterministic categorization
Validate schema/format 1 Haiku, GPT-4o-mini ~$0.001 Mechanical checking
Format output / template 1 Haiku, GPT-4o-mini ~$0.001 Structured transformation
Extract structured data 1 Haiku, GPT-4o-mini ~$0.001 Pattern matching
Summarize text 1-2 Haiku → Sonnet ~$0.001-0.01 Short summaries: Haiku; nuanced: Sonnet
Write content/docs 2 Sonnet, GPT-4o ~$0.01 Creative quality matters
Implement code 2 Sonnet, GPT-4o ~$0.01 Correctness + style
Review code/diffs 2 Sonnet, GPT-4o ~$0.01 Needs judgment, not just pattern matching
Research synthesis 2 Sonnet, GPT-4o ~$0.01 Multi-source reasoning
Decompose ambiguous problem 3 Opus, o1 ~$0.10 Requires deep understanding
Design architecture 3 Opus, o1 ~$0.10 Complex system reasoning
Judge output quality 3 Opus, o1 ~$0.10 Meta-reasoning about quality
Plan multi-step strategy 3 Opus, o1 ~$0.10 Long-horizon planning

Read the full file on GitHub · 170 lines

Files

What ships with it

2 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. 7d ago First seen · 170 lines · 121 tokens per session scan A fc1d57acf95b

Subscribe to this mod's changes

llm-router is a skill published in the GitHub repository curiositech/some_claude_skills (219 stars, last pushed 4d ago), licensed MIT. It adds 121 tokens to every session and 1,820 once invoked, about $0.0006 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 2026-09-03.

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