webbrain

WebBrain is a web browser extension that puts an AI agent in a side panel next to your tabs. Ask it about the page you're on, or hand it a task and let it click, type, and navigate its way through. It runs on the model you choose — a local llama.cpp or Ollama server, a frontier cloud API, or the managed default that needs no setup at all.

Install

Install from the Chrome Web Store, Firefox Add-ons, or Edge Add-ons.

git clone https://github.com/webbrain-one/webbrain.git

Chrome — open chrome://extensions/, enable Developer mode (top right), click Load unpacked, and select the webbrain/src/chrome folder.

Firefox — open about:debugging#/runtime/this-firefox, click Load Temporary Add-on, and select src/firefox/manifest.json. Temporary add-ons are removed when Firefox restarts; permanent installation requires signing via addons.mozilla.org.

Use it

Click the WebBrain icon to open the side panel, then type something like:

• "Summarize this page"
• "Find all links about pricing"
• "Fill in the search box with 'AI agents' and click Search"
• "Navigate to github.com and find trending repositories"

Three modes control what the agent is allowed to do:

Pick a model

WebBrain Cloud 1.0 is the default and needs no API key or local setup.

Local models need no API key either. Point WebBrain at any OpenAI-compatible server:

llama-server -m your-model.gguf --port 8080          # llama.cpp
ollama serve                                          # Ollama  → :11434/v1
vllm serve your-model --port 8000                     # vLLM    → :8000/v1
python -m sglang.launch_server --model-path your-model --port 30000

LM Studio (:1234/v1), Jan (:1337/v1), LocalAI (:8080/v1), and GPT4All (:4891/v1) work the same way. A generic Local OpenAI-compatible Proxy card also supports authenticated loopback gateways such as CLIProxyAPI; see the secure subscription proxy setup. Load a model with at least a 16k-token context window — 8k works only with the Compact tier, and 4k is too small for the system prompt plus tool schemas. WebBrain auto-detects the real window for llama.cpp, Ollama, and LM Studio, and auto-compacts the conversation as it fills up. For Ollama, llama.cpp, LM Studio, and LocalAI, it also reads native server metadata before adding screenshots; Settings provides Auto, Force on, and Off overrides. When the optional Model field is blank, the loaded-model capability is rechecked on every user turn so a server-side hot swap takes effect. There is also a preview ollama launch webbrain --model <model> handoff. Details: providers and models.

Cloud APIs — OpenAI, Anthropic Claude, Google Gemini, Azure OpenAI, AWS Bedrock, Mistral, DeepSeek, xAI Grok, MiniMax, Kimi, Qwen, z.ai GLM, Groq, Together, Cloudflare, Nvidia NIM, Hugging Face, Fireworks, OpenRouter, and more. Settings ships 106 built-in provider cards on Chromium (105 on Firefox), including an endpoint-free local WebGPU option with the tested LFM2.5 2.6B preset and an experimental custom Hugging Face ONNX repository option — see the full catalog.

Features

• Reads any page — text, links, forms, tables, PDFs, and interactive elements, via the accessibility tree rather than brittle selectors
• Acts on it — click, type, scroll, navigate, upload, download, and verify forms, with per-site permission prompts before consequential actions
• Plan before Act — Act and Dev can generate a structured plan, show it for approval, and pin the approved plan to the scratchpad before any tool runs
• Multi-step agent — autonomous tool-use loop, configurable up to 195 steps (default 130), with a Continue button when it hits the limit
• Saved workflows — turn a successful run into a reusable, value-free workflow you can re-run, export, and share
• Scheduled tasks and watches — /schedule for later, /watch to poll a page and act when a condition is met
• Skills — trusted instructions and tools that load only when relevant
• Smart context — token-aware auto-compaction, tool-result limits, and emergency overflow recovery
• Per-tab conversations — each tab keeps its own history; optional local user memory for stated preferences
• Reading-first side panel — streaming Ask replies, floating controls that keep your question in view as answers grow, copy buttons, a page-inspection banner, and a stop button that works mid-run
• Deterministic by default — temperature 0.15 for browser-control decisions, 0.3 for Ask, 0 for vision screenshot descriptions

Agent tools

WebBrain separates tier from mode. Tier (compact, mid, full) is a per-provider setting controlling how many tools a model sees — Compact suits small local models, Full unlocks hover, drag-drop, frames, and shadow DOM. Mode (ask, act, dev) controls what the user is allowing.

The full tool-by-tier matrix, WebMCP notes, and Dev-mode diagnostics are in agent tools.

Slash commands

Type /help in the panel for full signatures and flags. The most useful ones:

/watch runs its first check immediately, then polls every 60 seconds (--secs accepts 30–120). Relative conditions like "when a new commit appears" establis