A field guide to AI models

Every model gets a lesson: what it's good at, three real tasks, where it sits in your stack, and the request to paste.

The board

Pick a job. See which models do it, then open a lesson to learn how to use one.

Which model should run your agent loop?

Frontier models that plan, call tools, and edit code across many steps.

Intelligence index· Artificial Analysis via OpenRouter

Claude Opus 5.5

GPT-6.1 Sol

Claude Sonnet 5.5

Gemini 4 Argon

Grok 4.7

GLM 5.3

Kimi K3

#ModelBest atAA index$/M in · outContext
1The planner in a coding agent. Multi-step changes across a large codebase59.1$4 · $201.0MLesson
2The document-heavy agent. Agentic coding with tool calls54.6$2 · $101.1MLesson
3The everyday builder. Building a feature from a clear ticket54.5$2 · $101.0MLesson
4The brain when inputs are not just text. Reasoning over mixed media: video, audio, screenshots, and PDFs together50.4$2 · $101.0MLesson
5The self-checking engineer. Long-running software engineering tasks35.5$2 · $6500KLesson
6
GLM 5.3

Z.ai· open weights

The open-weight agent. Long-horizon coding agents on an open-weight model31.7$0.070 · $1.41.0MLesson
7
Kimi K3

Moonshot· open weights

The open-weight multimodal agent. Open-weight agents that also need to see images or video17.4$0.192 · $161.0MLesson

AA index = Artificial Analysis Intelligence Index, as published on each model's OpenRouter listing. A dash means the listing has no score. Prices are per million tokens, live from OpenRouter.

How a stack fits together

Five layers. Most apps use three.

A model is one part of a system. Learn the layers once, and every new release has an obvious place to go.

  1. Layer 01

    Retrieve

    Find the right context: embeddings and rerankers.

  2. Layer 02

    Plan & reason

    The main model: plans, calls tools, writes the hard parts.

  3. Layer 03

    Do the volume

    Fast models for subagents, extraction, and bulk text.

  4. Layer 04

    Gate & route

    Decision models return probabilities your code thresholds.

  5. Layer 05

    Draw, speak, listen

    Image, speech, and transcription models at the edges.

Recipes

Whole stacks you can copy.

Each one follows an OpenRouter cookbook, so the request shapes match the docs.

Tell us the job. Get a stack.

Describe what you're building. We'll suggest models for each layer and link the lessons that show you how.

Find my model