Cortex MCP server
Commit Sep 11, 2026Indexes a local repository so coding agents can search code, follow symbol relationships, and check change impact.
Also known as DanielBlomma/cortex, @danielblomma/cortex-mcp
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What is Cortex MCP?
Cortex indexes a local repository so coding agents can search code, follow symbol relationships, and check change impact.
Summary generated from the project's README
About Cortex MCP server
Providing AI coding agents with structured repository context is what Cortex enables by building a local map of code, symbols, and project rules. Instead of agents guessing or reading entire files, they query a local index through a CLI to find relevant information. This tool works entirely on your machine, ensuring your code stays private, and it requires Node.js 20.9+ and Git to function.
Developers use specific commands like cortex search to find code, cortex impact to estimate the blast radius of a change, and cortex guidance to get cited context before starting a task. The system maintains accuracy through a background watcher and Git hooks that perform incremental updates. While the primary workflow is via the CLI, you can use cortex connect for clients that require MCP compatibility. It is designed to help agents follow symbol relationships and respect active repository conventions without needing to call external network services for indexing.
What you can do with it
- 1Analyze change impactAsk an agent to estimate how a specific modification will affect the rest of the codebase.
- 2Find implementation patternsHave an AI agent identify nearby code patterns to ensure new code follows existing styles.
- 3Retrieve repository rulesDirect an agent to read the active project rules and architecture decisions before writing code.
- 4Perform code reviewsUse the tool to review staged or unstaged changes against the current head of the repository.
Written from the project's README. Every use case is checked against a quote from it.
How to install Cortex MCP
Formats verified 10 Nov 2026Install Cortex MCP in Claude Code
$ claude mcp add cortex -- npx -y @danielblomma/cortex-mcpInstall Cortex MCP in Cursor
~/.cursor/mcp.json
{
"mcpServers": {
"cortex": {
"command": "npx",
"args": [
"-y",
"@danielblomma/cortex-mcp"
]
}
}
}Install Cortex MCP in VS Code
.vscode/mcp.json
{
"servers": {
"cortex": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@danielblomma/cortex-mcp"
]
}
}
}Install Cortex MCP in Claude Desktop
claude_desktop_config.json
{
"mcpServers": {
"cortex": {
"command": "npx",
"args": [
"-y",
"@danielblomma/cortex-mcp"
]
}
}
}Install Cortex MCP in Codex
~/.codex/config.toml
[mcp_servers.cortex] command = "npx" args = ["-y", "@danielblomma/cortex-mcp"]
Install Cortex MCP in Gemini CLI
~/.gemini/settings.json
{
"mcpServers": {
"cortex": {
"command": "npx",
"args": [
"-y",
"@danielblomma/cortex-mcp"
]
}
}
}README
View on GitHubCortex
Give AI coding agents the right context from your repository.
Cortex builds a local map of your code, symbols, relationships, and project rules. Coding agents query that map through the CLI instead of guessing or reading the whole repository.
Your code stays on your machine. MCP is not required.
Start
Requires Node.js 20.9+ and Git.
npm install --global @danielblomma/cortex-mcp
cd your-project
cortex init --bootstrap
This indexes the repository, adds Cortex instructions to AGENTS.md, installs
Git hooks, and starts the background watcher.
Check the setup:
cortex doctor
Use
# Find relevant code.
cortex search "where is authentication handled?" --json
# Follow relationships from a search result.
cortex related <entity-id> --json
# See what a change may affect.
cortex impact "authentication" --json
# Read repository rules.
cortex rules --json
# Compare a changed file with nearby patterns.
cortex pattern-evidence src/auth.ts --json
# Inspect deterministic active conventions for a file or indexed entity.
cortex conventions src/payments/retry.ts --json
# Get cited, deterministic context before implementing a code task.
cortex guidance src/payments/retry.ts --task "add bounded retry handling" --json
# Review the staged, unstaged, and non-ignored untracked candidate against HEAD.
cortex review --diff --json
# Refresh context after significant changes.
cortex update
Agents can run these commands directly. cortex init adds instructions that
tell them to search before answering and check impact before refactoring. They
do not need an MCP connection.
What Cortex adds
Without Cortex, an agent often searches by filename and reads many unrelated files. Cortex gives it structured repository context:
- semantic search across code, rules, and architecture decisions;
- symbol definitions and file relationships;
- caller and dependency traversal;
- impact analysis before refactoring;
- active rules, deprecations, and source-of-truth signals;
- deterministic, subsystem-scoped convention profiles with cited reusable symbols;
- incremental updates after Git and filesystem changes.
The pipeline is local and straightforward:
repository -> local index -> Cortex CLI -> coding agent
Commands you will use
| Command | Purpose |
|---|---|
cortex search "..." --json |
Find relevant code and context |
cortex related <entity-id> --json |
Follow relationships from a result |
cortex impact "..." --json |
Estimate the blast radius of a change |
cortex rules --json |
Show active repository rules |
cortex pattern-evidence <file> --json |
Find nearby implementation patterns |
cortex conventions <file-or-entity> --json |
Inspect bounded repository convention profiles |
cortex guidance <file-or-entity> --task <text> --json |
Get bounded cited pre-coding guidance |
cortex review --diff --json |
Review the current Git candidate with cited local evidence |
cortex update |
Refresh changed context |
cortex status |
Show index status |
cortex doctor |
Diagnose the local setup |
cortex watch status |
Check background synchronization |
cortex dashboard |
Open the local status dashboard |
Run cortex help for the complete command list.
cortex conventions uses only the local index. It returns bounded, live-backed
version-1 profiles and does not call a model, planner, provider, or network
service. See Repository convention profiles
for the exact eligibility, limit, hashing, persistence, and safety contract.
Before implementing a code task, use cortex guidance as cited additive
context—not policy authority. Continue to use normal search, related, and
impact when needed, and never skip explicit active rules or conflicts. The
command is local-only and inspection-only; see the exact versioned contract in
Pre-coding guidance.
After coding and before finalization, use cortex review --diff. It separates
exact source-of-truth violations from heuristic local-pattern warnings and is
inspection-only. See Deterministic diff review.
Keep the index fresh
Git hooks and the watcher normally update Cortex automatically.
cortex status
cortex watch status
cortex update
Run cortex update manually after a large change or when results look stale.
Large repositories
Make lexical and graph search available first while semantic indexing continues in the background:
cortex bootstrap --background --profile interactive
cortex indexing status --json
This mode supports macOS, Linux, and WSL. Native Windows should use normal foreground bootstrap.
Upgrade
npm install --global @danielblomma/cortex-mcp@latest
cortex init --force
cortex bootstrap
cortex update
Project configuration and rules are preserved. See CHANGELOG.md for version-specific notes.
Optional MCP compatibility
The normal Cortex workflow uses the CLI. If a client explicitly requires MCP,
run cortex connect.
DeepSeek Harness integration
Cortex supports DeepSeek Harness through the V1 explicit tools and skills
integration. Cortex 2.6.0 contains and validates the integration source against
the pinned Harness 0.1.1-rc.2 release. Separate npm bundle distribution is
deferred and currently unavailable.
The bundle provides four agent-scoped tools (cortex_search,
cortex_related, cortex_impact, and cortex_rules) and five Cortex behavior
skills (change-impact, context-review, pattern-review, repo-research,
and using-cortex). Retrieval is local, repository-scoped, explicit, and
user-controlled. The integration does not automatically initialize, update,
or watch a repository.
V2 proactive/assistive retrieval remains planned and experimental; it is not included in Cortex 2.6.0. See the V1-to-V2 integration plan for details.
Links
License
MIT
Cortex MCP questions
How do I add Cortex MCP to Claude Code?
Run claude mcp add cortex -- npx -y @danielblomma/cortex-mcp in your terminal. Add --scope user to make it available in every project.
How do I add Cortex MCP to Cursor?
Open ~/.cursor/mcp.json and add the server under mcpServers, using the Cursor config shown in the install section above.
Does Cortex send my code to a remote service?
No. The index is built and queried locally, and the code stays on your machine.
Does Cortex require an MCP connection?
No. Agents run Cortex CLI commands directly; MCP is optional for clients that explicitly require it.
How do I set up Cortex in my project?
Install the npm package globally, then run cortex init --bootstrap in the project directory. This indexes the repo, adds instructions to AGENTS.md, installs Git hooks, and starts the watcher.
How do I keep the index up to date?
Git hooks and a background watcher normally update Cortex automatically, but you can run cortex update manually after large changes.
How do I analyze what a change might affect?
Run cortex impact on a topic to estimate the blast radius before refactoring.