Edit your Contract

The Data Contract Editor is a web-based visual editor for ODCS data contracts. It is hosted at editor.datacontract.com, and the CLI can launch it locally against a file on your machine.

Edit a local file

datacontract edit odcs.yaml

This starts a local web server and opens the Data Contract Editor for the given file in your browser. The editor is bundled with the CLI, so no internet access is required. Saving in the editor writes directly back to the local file.

Key behaviors:

• If the file does not exist, you are asked whether to initialize a new data contract.
• If a URL is given, you are asked whether to download a local copy, which is then edited.
• The server also acts as the editor's test runner: clicking "Run test" in the editor executes the data contract tests locally against the servers defined in the contract. Credentials for the data sources must be provided as environment variables — see Test your Data.

Requirements

The edit command requires the api extra:

pip install 'datacontract-cli[api]'

The editor assets (JS/CSS) are bundled with the CLI and work offline by default. You can change where they are loaded from:

• --editor-version — load a specific version of the datacontract-editor npm package from the CDN, e.g. 0.1.9 or latest.
• --editor-assets-url — load assets from a self-hosted editor build. Takes precedence over --editor-version.

AI Assistant

The editor's AI assistant is enabled when DATACONTRACT_EDITOR_AI_ENDPOINT is set. Like data source credentials, these variables can be set in a .env file.

Environment variable	Description
DATACONTRACT_EDITOR_AI_ENDPOINT	Chat completions URL (OpenAI-compatible) or Messages URL (Anthropic).
DATACONTRACT_EDITOR_AI_API_KEY	API key. The key is passed to the browser, which calls the endpoint directly.
DATACONTRACT_EDITOR_AI_MODEL	Model name, e.g. gpt-4o or claude-sonnet-4-5.
DATACONTRACT_EDITOR_AI_PROVIDER	openai (default) or anthropic.
DATACONTRACT_EDITOR_AI_AUTH_HEADER	bearer (default), api-key (Azure OpenAI), or x-api-key (Anthropic).

export DATACONTRACT_EDITOR_AI_PROVIDER=anthropic
export DATACONTRACT_EDITOR_AI_ENDPOINT=https://api.anthropic.com/v1/messages
export DATACONTRACT_EDITOR_AI_API_KEY=sk-ant-...
export DATACONTRACT_EDITOR_AI_MODEL=claude-sonnet-4-5
export DATACONTRACT_EDITOR_AI_AUTH_HEADER=x-api-key
datacontract edit datacontract.yaml

Options

Option	Default	Description
--port	4243	Bind the local server to this port.
--host	127.0.0.1	Bind to this host. For Docker, set it to 0.0.0.0.
--editor-version	bundled	Version of the datacontract-editor npm package to load from the CDN.
--editor-assets-url	—	Base URL to load editor assets from (e.g. a self-hosted build).
--open / --no-open	--open	Open the editor in the default browser.
--debug / --no-debug	--no-debug	Enable debug logging.

Example

datacontract edit datacontract.yaml

See the edit command reference for the full signature.