Practical overview
When it fits
Use it when a TypeScript workflow needs LLM-based structured extraction from supplied page content, or HTML-to-Markdown preprocessing before an LLM step.
Who it is for
- TypeScript developers adding web-content extraction to applications or data pipelines.
- Teams preprocessing HTML for LLM use or collecting structured fields from product pages.
Documented uses
- Extract schema-defined fields from HTML, Markdown or plain text.
- Convert HTML to Markdown and optionally focus on main content or clean tracking parameters from URLs.
- Recover malformed JSON output and handle relative or invalid URLs in extracted content.
- Load pages with Playwright before extraction, or pair with a separate browser agent when page interaction is needed.
Requirements & limits
The project is an open-source TypeScript library under the Apache-2.0 license. Its README identifies `@langchain/core` as a required peer dependency.
- HTML input requires a source URL to handle relative URLs correctly.
- The extraction function requires an LLM instance, content, content format and Zod schema.
- A LangChain provider integration must be installed separately; the README names OpenAI, Google Gemini, Anthropic and Ollama integrations.
- The optional input-token limit can truncate content when the configured threshold is exceeded.
- Repository integration tests require valid provider API keys; unit tests do not make API calls.
Check current requirements in the official documentation. Source-based guidance does not mean OpenViST has run or independently tested this project.
Install Extractor and configure an LLM provider
Set up the library and provider dependencies for a TypeScript project.
Before you start
- A TypeScript project with Node package installation available.
- A LangChain chat-model provider to use with the library.
- Provider API credentials if the selected model requires them.
Steps
Install
@lightfeed/extractorand@langchain/core.Install the LangChain integration package for the chosen provider, such as
@langchain/openai,@langchain/google-genai,@langchain/anthropicor@langchain/ollama.Configure the provider’s model instance and credentials for the project.
Expected outcome
The project has the documented library and provider dependencies needed to configure an LLM for extraction.
Guide limitations
- The README setup steps do not by themselves perform an extraction.
- Provider credentials and model configuration depend on the selected integration.
Sources & review
Source record details
- Source availability
- Active
- Sources checked
- 12 October 2026
- Original website title
- lightfeed/extractor · Official homepage title · retained in its source language

