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.
npx agentmods add instructions/anomalyco/models.dev/agents-mdgit clone --depth 1 https://github.com/anomalyco/models.devWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.03107 | $0.03107 |
| Opus 5 | $0.01554 | $0.01554 |
| Sonnet 5 | $0.00621 | $0.00621 |
| Haiku 4.5 | $0.00311 | $0.00311 |
Grade A, and why
models.dev AGENTS.md 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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 274 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent Guidelines for models.dev
Catalog-only. This file is how to add and maintain models and providers. Nothing else.
Validate
bun validate
Run this after every catalog change. It must pass before a PR is mergeable.
Two concepts: lab models vs providers
| Lab model metadata | Provider model | |
|---|---|---|
| What | Provider-agnostic facts about a model the lab built | How a specific API host serves that model |
| Where | models/<lab-id>/<model-id>.toml |
providers/<provider-id>/models/.../<id>.toml |
| Examples | models/anthropic/claude-opus-4-6.toml, models/openai/gpt-5.4.toml |
providers/openrouter/models/anthropic/claude-opus-4.6.toml |
| Contains | name, description, capabilities, modalities, limits, weights, … | cost, reasoning_options, status, request shape, and only real overrides |
- Labs create models (Anthropic, OpenAI, Google, DeepSeek, Alibaba, …).
- Providers host or relay them (the lab’s own API, OpenRouter, Bedrock, a random OpenAI-compatible gateway, …).
Filename (minus .toml) is the model id. Never put an id field in the TOML. Schema is strict — unknown keys fail validation.
When to use base_model (blocker)
If the provider did not create the model, the provider entry must use base_model.
- Identify the underlying lab model.
- If
models/<lab>/<model>.tomlis missing, add it under the lab that made the model, then pointbase_modelat it. - Provider file stays override-only (see below).
base_model = "anthropic/claude-opus-4-6"
[cost]
input = 5.00
output = 25.00
Exceptions (full inline definition allowed)
Use a full standalone provider model TOML only when:
- The provider is the lab (first-party host of its own model), or
- The model is unique to that host — private beta alias, custom/fine-tune, or something with no sensible shared lab identity elsewhere.
If you can name the lab model, it belongs in models/ and the host uses base_model. Do not skip creating models/ just because the file did not exist yet.
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.
- yesterday First seen · 274 lines · 3,107 tokens per session scan A 2fe731fca0d6
models.dev AGENTS.md is an instructions file published in the GitHub repository anomalyco/models.dev (6,649 stars, last pushed yesterday), licensed MIT. It adds 3,107 tokens to every session, about $0.0155 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.
Other instructions, from other repositories
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
buildNext
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
spec-kit AGENTS.md
Instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
langchain AGENTS.md
Instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.