Langflow Agent Rules

Build AI applications with visual workflows and Python components.

Overview

Langflow maps its Python backend, frontend, and component system. It explains dependency direction, distinguishes an authorization interface from the plugin that enforces it, and protects class names stored in saved flows. Each package has its own environment and tests.

Architecture as narrative Hard prohibitions Verification by change type

Documents

├── 
├──  · imports AGENTS.md, .claude/CLAUDE.md (unavailable)
└── .claude
    └── CLAUDE.md · unavailable at this commit

Techniques in this file

01 / Architecture as narrative

Make dependency direction explicit

The package chain gives an agent a way to judge where new imports and provider integrations belong. Architecture is described as a dependency constraint, beyond a directory listing.

93The public dependency direction is `langflow → langflow-core → langflow-base → lfx`.

02 / Architecture as narrative

Distinguish a switch from enforcement

The authorization notes explain that enabling the interface alone does not introduce a deny policy. An agent changing permission-sensitive behavior must account for the registered implementation.

112Default is **off**: `LANGFLOW_AUTHZ_ENABLED=false`. When enabled with only the OSS stub registered, every check returns allow — the stub is a no-op so routes stay wired and audit rows still flow. Real allow/deny requires a registered authorization plugin.

03 / Hard prohibitions

Protect identifiers stored in user data

Class names are part of saved-flow compatibility. A rename that looks local in Python can break existing documents, so the instruction calls it out as a persistent contract.

147**IMPORTANT:** Changing a component's class name is a breaking change and should never be done. The class name serves as an identifier used to match components in saved flows and to flag them for updates in the UI. Renaming it will break existing flows that use that component.

04 / Verification by change type

Include the subpackage development environment

The test setup names the package whose development dependencies must be synchronized. A root install is not evidence that component test dependencies are present.

198- When running tests inside a sub-package (e.g. `langflow-base`, `lfx`), sync that package's dev group first: `uv sync --group dev --package langflow-base`. The default `uv sync` only resolves the top-level workspace and may leave dev-only test deps (e.g. `fakeredis`) uninstalled.