Build Extraction Schemas with the API

Use the API to programmatically generate a JSON extraction schema from the Markdown output of the API. The API analyzes the Markdown content and returns a schema you can pass directly to the API.

This is useful when you want to automate schema creation or refinement as part of a larger pipeline, without using the Playground schema wizard.

Endpoint: https://api.va.landing.ai/v1/ade/extract/build-schema

See the full API reference here.

For schema format requirements and supported field types, see Extraction Schema (JSON).

Request Parameters

At least one of markdowns, markdown_urls, or prompt must be provided.

Parameter	Type	Required	Description
model	string	No	The extraction model to use. Use extract-latest for the latest version.
markdowns	file or string	No	One or more Markdown files or inline Markdown strings to analyze. Provide multiple Markdown files for better schema coverage.
markdown_urls	array of strings	No	URLs to Markdown files to analyze.
prompt	string	No	Instructions for how to generate or modify the schema.
schema	string	No	An existing JSON schema to refine or iterate on.

Response

The response contains:

• extraction_schema (string): The generated JSON schema, returned as a string.
• metadata: Includes job_id, duration_ms, credit_usage, and version.

Workflows

Generate a Schema from Markdown Files

Pass one or more Markdown files to generate a schema based on the content. The API identifies the fields present in the Markdown file and returns an extraction schema.

curl -X POST 'https://api.va.landing.ai/v1/ade/extract/build-schema' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -F 'markdowns=@markdown.md' \
  -F 'model=extract-latest'

To improve coverage, pass multiple Markdown files that represent the range of layouts you expect to process:

curl -X POST 'https://api.va.landing.ai/v1/ade/extract/build-schema' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -F 'markdowns=@markdown_1.md' \
  -F 'markdowns=@markdown_2.md' \
  -F 'model=extract-latest'

Generate a Schema from a Prompt

Use the prompt parameter to specify which fields to extract. This is useful when you only need a subset of the fields in the Markdown file, or when you want to shape the field names and structure.

curl -X POST 'https://api.va.landing.ai/v1/ade/extract/build-schema' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -F 'markdowns=@markdown.md' \
  -F 'model=extract-latest' \
  -F 'prompt=Extract the vendor name, invoice date, and total amount due'

You can also use prompt without any Markdown input to generate a schema based on instructions alone:

curl -X POST 'https://api.va.landing.ai/v1/ade/extract/build-schema' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -F 'model=extract-latest' \
  -F 'prompt=Create a schema for extracting patient name, date of birth, and insurance provider from medical intake forms'

Refine an Existing Schema

Pass an existing schema in the schema parameter to refine it. For example, you may have a schema you built in the Playground or created manually, and want to update it based on new documents or instructions.

To refine a schema based on a Markdown file:

curl -X POST 'https://api.va.landing.ai/v1/ade/extract/build-schema' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -F 'markdowns=@markdown.md' \
  -F 'model=extract-latest' \
  -F 'schema={"type":"object","properties":{"vendor":{"type":"string"},"total":{"type":"number"}}}'

To update a schema based on a prompt:

curl -X POST 'https://api.va.landing.ai/v1/ade/extract/build-schema' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -F 'model=extract-latest' \
  -F 'schema={"type":"object","properties":{"vendor":{"type":"string"},"total":{"type":"number"}}}' \
  -F 'prompt=Add a field for the invoice number and make the total field return a string with the currency symbol'