What is Spiderbrain?
Spiderbrain, sometimes searched as Spider Brain, is the cognition layer for AI coding: a living map of your codebase that gives AI agents persistent memory and tells them exactly what a change will break.
Most AI coding tools forget. The moment a chat window closes, the context is gone, and the next session starts from zero. Spiderbrain fixes that. It ingests every file, dependency, decision and change into one always-current graph, then serves that graph to your AI agents so they reason over the real structure of your project instead of re-reading text every time.
The problem it solves
A large codebase is mostly invisible relationships. Which files are load-bearing? What breaks if you change this one function? Which decisions are going stale? Humans lose this map over time, and language models never had it. Spiderbrain makes the structure explicit and keeps it current, so neither you nor your agent is flying blind.
How Spiderbrain works
- It builds a context graph. Every file and dependency becomes a node and an edge in one deterministic graph, built on your machine from your files.
- It scores what matters. Each node gets a severity score (how much its failure would hurt) and a blast radius (how much breaks along with it).
- It finds the keystones. The few hubs everything leans on are surfaced as masters, the natural firebreaks in a cascade.
- It serves agents over MCP. The graph drops into Claude, Cursor, Continue and any Model Context Protocol client, so agents inherit memory and reasoning that stays current.
Agentic chat that understands your codebase
Spiderbrain includes an in-app agentic chat. Unlike a generic coding assistant, it is grounded in your brain, so it knows the shape of your project and what your change will break before it makes it.
It knows your codebase
The chat retrieves the files that matter, ranked by importance (webscore), so the AI answers with the right context instead of guessing.
It warns before it breaks things
Before any edit, it shows the blast radius, how many files depend on what you are about to change, and waits for your approval.
Your models, your keys
Multi-provider: Anthropic, OpenAI, Google, or local models through Ollama and LM Studio. Bring your own key, or run fully private and offline.
Ask, or Agent
Switch between read-only questions and an agent that proposes and applies scoped edits, each behind a diff with one-step undo.
How Spiderbrain helps you
Agents that remember
Persistent memory across every session, not just the current chat window.
Know what breaks
Severity and blast-radius scores tell you the real impact of a change before you ship it.
Find what matters
Importance scoring surfaces the handful of files that carry the whole project.
Always current
The map updates itself as you work. No manual re-indexing, no stale embeddings.
Local-first
The brain is built on your machine from your files. Your source code stays on your device.
Plugs into your tools
MCP-native: Claude, Claude Code, Cursor, Continue, Zed, Windsurf and more, with no glue code.
Who it is for
Developers and teams who use AI agents and want them to actually understand the codebase, not just autocomplete it. It suits a solo engineer keeping one project coherent, and it scales to a team that needs one shared, deterministic brain. It also works on any corpus, not only code: docs, records and decisions all fit the same graph.