agent-web-interface
A unified perception and interaction interface that enables AI agents to use the web efficiently
Agent Web Interface
An MCP server for browser automation that exposes semantic, token-efficient page representations optimized for LLM agents.
Motivation
LLM-based agents operate under strict context window and token constraints.
However, most browser automation tools expose entire DOMs or full accessibility trees to the model.
This leads to:
- Rapid token exhaustion
- Higher inference costs
- Reduced reliability as relevant signal is buried in noise
In practice, agents spend more effort finding the right information than reasoning about it.
Agent Web Interface exists to change the unit of information exposed to the model.
Core Idea: Semantic Page Snapshots
Instead of exposing raw DOM structures or full accessibility trees, Agent Web Interface produces semantic page snapshots.
These snapshots are:
- Compact and structured
- Focused on user-visible intent
- Designed for LLM recall and reasoning, not DOM completeness
- Stable across layout shifts and DOM churn
The goal is not to mirror the browser, but to present the page in a form that aligns with how language models reason about interfaces.
How It Works
At a high level:
- The browser is controlled via Puppeteer and CDP
- The page is reduced into semantic regions and actionable elements
- A structured snapshot is generated and sent to the LLM
- Actions are resolved against stable semantic identifiers rather than fragile selectors
This separation keeps:
- Browser lifecycle management isolated
- Snapshots deterministic and low-entropy
- Agent reasoning predictable and efficient
Benchmarks
Early benchmarks against Playwright MCP show:
- ~19% fewer tokens consumed
- ~33% faster task completion
- Same or better success rates on common navigation tasks
Benchmarks were run using Claude Code on representative real-world tasks.
Results are task-dependent and should be treated as directional rather than absolute.
What Agent Web Interface Is (and Is Not)
Agent Web Interface is:
- A semantic interface between browsers and LLM agents
- An MCP server focused on reliability and efficiency
- Designed for agent workflows, not test automation
Agent Web Interface is not:
- A general-purpose browser
- A visual testing or screenshot framework
- A replacement for Puppeteer
Puppeteer remains the execution layer; Agent Web Interface focuses on representation and reasoning.
Usage
Agent Web Interface implements the Model Context Protocol (MCP) and works with:
- Claude Code
- Claude Desktop
- Cursor
- VS Code
- Any MCP-compatible client
Example workflows include:
- Navigating complex web apps
- Handling login and consent flows
- Performing multi-step UI interactions with lower token usage
Claude Code
# Basic (auto-launches browser)
claude mcp add agent-web-interface -- npx agent-web-interface@latest
# With auto-connect to your Chrome profile (set via env var)
claude mcp add agent-web-interface -e AWI_CDP_URL=http://localhost:9222 -- npx agent-web-interface@latest
CLI Arguments
The server accepts transport-level arguments only. Browser configuration is per-session via the navigate tool.
| Argument | Description | Default |
|---|---|---|
--transport |
Transport mode: stdio or http |
stdio |
--port |
Port for HTTP transport | 3000 |
Browser Session Configuration
Browser initialization is automatic on the first tool call. The navigate tool accepts optional parameters to configure the session:
| Parameter | Description | Default |
|---|---|---|
headless |
Run browser in headless mode | false |
isolated |
Use an isolated temp profile instead of persistent | false |
auto_connect |
Auto-connect to Chrome 144+ via DevToolsActivePort | false |
Examples:
# Auto-launch visible browser (default)
npx agent-web-interface
# HTTP transport mode
npx agent-web-interface --transport http --port 8080
# Connect to existing CDP endpoint via env var
AWI_CDP_URL=http://localhost:9222 npx agent-web-interface
Using Your Existing Chrome Profile (Chrome 144+)
To connect with your bookmarks, extensions, and logged-in sessions:
- Navigate to
chrome://inspect/#remote-debuggingin Chrome - Enable remote debugging and allow the connection
- Use the
auto_connectparameter on thenavigatetool, or setAWI_CDP_URL
{
"mcpServers": {
"agent-web-interface": {
"command": "npx",
"args": ["agent-web-interface@latest"],
"env": {
"AWI_CDP_URL": "http://localhost:9222"
}
}
}
}
Environment Variables
| Variable | Description | Default |
|---|---|---|
AWI_CDP_URL |
CDP endpoint (http or ws) to connect to existing browser | - |
AWI_TRIM_REGIONS |
Set to false to disable region trimming globally |
true |
TRANSPORT |
Transport mode override (http) |
- |
HTTP_HOST |
Host for HTTP transport | 127.0.0.1 |
HTTP_PORT |
Port for HTTP transport | 3000 |
LOG_LEVEL |
Logging level | info |
CEF_BRIDGE_HOST |
CDP host for CEF bridge connection | 127.0.0.1 |
CEF_BRIDGE_PORT |
CDP port for CEF bridge connection | 9223 |
BRING_TO_FRONT |
Set to true to focus the Chrome tab before each action |
false |
CHROME_PATH |
Path to Chrome executable (multi-tenant) | - |
Installation
git clone https://github.com/lespaceman/agent-web-interface
cd agent-web-interface
npm install
npm run build
Configure the MCP server in your client according to its MCP integration instructions.
Architecture Overview
Agent Web Interface separates concerns into three layers:
- Browser lifecycle — page creation, navigation, teardown
- Semantic snapshot generation — regions, elements, identifiers
- Action resolution — mapping agent intent to browser actions
This separation allows each layer to evolve independently while keeping agent-visible behavior stable.
Status
Agent Web Interface is under active development.
APIs and snapshot formats may evolve as real-world agent usage informs the design.
Feedback from practitioners building agent systems is especially welcome.
License
MIT
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