deepagents AGENTS.md

A set of repository instructions for contributors working on LangChain's Deep Agents monorepo, a code repository containing multiple related packages. It covers development, security review, linting, testing, and release practices.

In plain words
What is it for?
Use it when modifying the Deep Agents repository, especially when planning changes, running checks, handling lint exceptions, or preparing releases.
Why use it?
It gives coding agents the project-specific rules they need before changing code. It also points them to the correct documents for architecture, development, and releases.

Instructions file for CodexOpenCode

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 instructions/langchain-ai/deepagents/agents-md
Clone the repo
git clone --depth 1 https://github.com/langchain-ai/deepagents

Made for: Codex, OpenCode.

Per session 2,268 This file is loaded in full into every session.
When invoked 2,268 The same file — it is already loaded in full.
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 $0.02268 $0.02268
Opus 5 $0.01134 $0.01134
Sonnet 5 $0.00454 $0.00454
Haiku 4.5 $0.00227 $0.00227

Measured 3d ago against content hash 46b5bf4789af, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

deepagents 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 3d 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.

AGENTS.md · 155 lines

How it starts

The opening of the file, as written. The whole thing — 155 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Global development guidelines for the Deep Agents monorepo

This file contains repository-wide rules for agents and contributors. Use these sources for details instead of duplicating them here:

Corridor security analysis

When Corridor's analyzePlan tool is available, create a plan and use the tool to analyze it before generating or modifying code. Apply the resulting security guidance before writing code.

Development workflow

Work inside the package you are changing; libs/DEVELOPMENT.md covers environment setup (uv, make) and the edit-test-lint loop.

Do not add dependencies unless required. When adding one, justify its maintenance, adoption, and release activity.

Suppressing ruff rules

Use inline # noqa: RULE with a justification for individual exceptions. Reserve [tool.ruff.lint.per-file-ignores] for categorical policies that apply to a whole class of files, such as tests not requiring docstrings. Do not hide a single violation with a file-wide ignore. If you cannot justify a suppression, the code is probably the problem. See libs/DEVELOPMENT.md for worked examples.

PR conventions

Titles and scope

Follow Conventional Commits and include a scope. Allowed types and scopes are defined in .github/workflows/pr_lint.yml.

  • Start the text after type(scope): with a lowercase letter unless it begins with a proper noun or named code entity.
  • Wrap class, function, method, parameter, and variable names in backticks.
  • Do not put Linear issue-closing markers in titles; put issue relationships in the PR body.
  • For version-branch syncs, use chore(repo): sync main into vX.Y; release is a type, not a scope.
  • Keep each bump-worthy PR to one releasable component. Put cross-package dependency or lockfile churn in a separate chore(deps): PR. See multi-component fan-out and lockfile churn fan-out.

Read the full file on GitHub · 155 lines

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. 3d ago First seen · 155 lines · 2,268 tokens per session scan A 46b5bf4789af

Subscribe to this mod's changes

deepagents AGENTS.md is an instructions file published in the GitHub repository langchain-ai/deepagents (28,825 stars, last pushed yesterday), licensed MIT. It adds 2,268 tokens to every session, about $0.0113 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.