Plasmate SOM Action

A GitHub Action that fetches a web page with Plasmate and outputs the Semantic Object Model (SOM). SOM uses 4x fewer tokens than raw HTML while preserving page structure, element roles, and interactive affordances.

Usage

- uses: plasmate-labs/som-action@v1
  with:
    url: https://example.com
  id: som

- run: echo "Page title: ${{ steps.som.outputs.title }}"

Inputs

Input	Required	Default	Description
url	✅	—	URL to fetch
format	❌	json	Output format (json or text)

Outputs

Output	Description
som	The full SOM JSON output
title	Page title extracted from the SOM
tokens	Approximate token count of the SOM

Examples

Fetch and use in subsequent steps

name: Scrape and Process

on:
  workflow_dispatch:
    inputs:
      url:
        description: 'URL to scrape'
        required: true

jobs:
  scrape:
    runs-on: ubuntu-latest
    steps:
      - uses: plasmate-labs/som-action@v1
        with:
          url: ${{ github.event.inputs.url }}
        id: som

      - name: Display results
        run: |
          echo "Title: ${{ steps.som.outputs.title }}"
          echo "Tokens: ${{ steps.som.outputs.tokens }}"

      - name: Save SOM
        run: echo '${{ steps.som.outputs.som }}' > som.json

      - uses: actions/upload-artifact@v4
        with:
          name: som-output
          path: som.json

Scheduled monitoring

name: Monitor Page Changes

on:
  schedule:
    - cron: '0 */6 * * *'  # Every 6 hours

jobs:
  monitor:
    runs-on: ubuntu-latest
    steps:
      - uses: plasmate-labs/som-action@v1
        with:
          url: https://example.com/status
        id: som

      - name: Check for changes
        run: |
          echo "Current title: ${{ steps.som.outputs.title }}"
          # Add your change detection logic here

How It Works

1. Builds a Docker container with Plasmate installed
2. Fetches the specified URL using plasmate fetch
3. Parses the SOM JSON to extract metadata
4. Outputs the full SOM and extracted fields as step outputs

License

MIT

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Part of the Plasmate Ecosystem

Engine	plasmate - The browser engine for agents
MCP	plasmate-mcp - Claude Code, Cursor, Windsurf
Extension	plasmate-extension - Chrome cookie export
SDKs	Python / Node.js / Go / Rust
Frameworks	LangChain / CrewAI / AutoGen / Smolagents
Tools	Scrapy / Audit / A11y / GitHub Action
Resources	Awesome Plasmate / Notebooks / Benchmarks
Docs	docs.plasmate.app
W3C	Web Content Browser for AI Agents