contextatlas — Claude Code MCP server: codebase context in one call
Bundles code structure, ADR decisions, git history and test links into a single context payload. Fewer tokens spent hunting through a repo.
claude mcp add contextatlas -- npx -y contextatlasWhat contextatlas does
ContextAtlas is an MCP server that hands the agent a prepared slice of your codebase per symbol. Four signals go in: language-server data (definition, references, types, diagnostics), architectural decisions pulled from ADRs and docs, git history with hot and cold markers, plus test associations. All of it comes back fused in one response instead of a run of greps and file reads.
No ADRs in the repo? You still get structure, git and tests. More signals make the bundle denser. Token savings scale with codebase size, while architectural intent capture does not — a 30-file library can carry constraints the agent should see before touching anything.
Install runs through npx, no separate server process to babysit. Cursor and GitHub Copilot need the MCP config written into their settings files by hand. Without ADRs part of the value is missing, which is a reason to write down a couple of decisions you already follow.
What it helps with
- pull context for a symbol in one call instead of repeated greps
- surface architectural constraints before the agent proposes a change
- locate tests that reference a given class or function
- check how often a symbol changed in recent commits
- cut token spend when reading an unfamiliar repository
Example prompts for the agent
- Give me context on
OrderProcessorbefore I change it - Which ADRs touch the billing module?
- Show me which tests cover
charges.ts
How to install contextatlas
Platform CLI
claude mcp add contextatlas -- npx -y contextatlasPlatform CLI
codex mcp add contextatlas -- npx -y contextatlasConfig file
{
"mcpServers": {
"contextatlas": {
"command": "npx",
"args": [
"-y",
"contextatlas"
]
}
}
}Config file
{
"servers": {
"contextatlas": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"contextatlas"
]
}
}
}Platform CLI
gemini mcp add contextatlas npx -y contextatlasStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about contextatlas
How do I install contextatlas in Claude Code?
Run claude mcp add contextatlas -- npx -y contextatlas. The server then becomes available to the agent in that project.
What does contextatlas do?
It returns one context bundle per symbol: language-server structure, ADR excerpts, git history and related tests. That replaces a dozen separate file lookups.
Do I need ADRs in my repository?
No. Without them the server still returns structure, git and tests. With ADRs the bundles get richer because architectural decisions are keyed to specific symbols.
