Ctxo

What is Ctxo? ​

Ctxo is a Model Context Protocol (MCP) server that turns your repository into a queryable knowledge base for AI coding assistants. Instead of letting an agent grep its way through files one at a time, Ctxo serves Logic-Slices: a symbol plus all transitive dependencies, git commit intent, anti-pattern warnings, and change-health scores, all in a single sub-500ms call.

What Ctxo is ​

  • An MCP server over stdio, compatible with Claude Code, Cursor, Copilot, Windsurf, Cline, and any raw MCP client.
  • A CLI (@ctxo/cli) that builds and maintains a committed, deterministic index of your code at .ctxo/.
  • 14 semantic tools spanning impact analysis (get_blast_radius, get_pr_impact), retrieval (get_ranked_context, search_symbols), navigation (find_importers, get_class_hierarchy), and health (find_dead_code, get_change_intelligence).
  • Language-pluggable: TypeScript/JavaScript (ts-morph), Go (tree-sitter), and C# (Roslyn + tree-sitter) ship today; more plugins via the v1 protocol.

What Ctxo is NOT ​

  • Not a code search engine. Grep finds text; Ctxo traces call graphs, inheritance trees, and reverse dependencies.
  • Not a linter. Ctxo surfaces anti-patterns from git history (reverts, hotfix chains), not from static rules.
  • Not an LSP replacement. Ctxo is built for agent-sized context windows, not IDE cursor completions.
  • Not cloud-hosted. Everything runs locally. Your code never leaves your machine.
  • Not a memory layer. Ctxo does not remember your chats, prompts, or agent state. It answers fresh from the committed index every call.
  • Not a context compressor. Ctxo does not summarise or shrink existing context. It precomputes the right context — dependency-aware slices, sized to a token budget — so the agent never has to read the whole file.

How it fits together ​

  +-------------------+     MCP/stdio     +-------------------+
  | Claude Code /     | <---------------> | @ctxo/cli         |
  | Cursor / Copilot  |   JSON-RPC        | (MCP server)      |
  +-------------------+                   +---------+---------+
                                                    |
                                                    v
                                    +---------------+---------------+
                                    | .ctxo/                        |
                                    |   index/   (committed JSON)   |
                                    |   .cache/  (local SQLite)     |
                                    +---------------+---------------+
                                                    ^
                                                    | Ctxo indexer
                                                    |
                                            +-------+--------+
                                            | Your codebase  |
                                            +----------------+

The agent never reads raw files to orient itself. It calls an MCP tool, Ctxo resolves the query against the pre-built index, and the agent gets a structured, token-budgeted answer.

Why sub-500ms matters ​

Agents think in tool-call loops. Every second of latency on a navigation call compounds across a task. Ctxo's SQLite cache and deterministic symbol IDs mean a get_blast_radius on a symbol with 200 downstream dependents returns before your agent finishes thinking about the next step.

Next steps ​

Released under the MIT License.

Copyright © 2024–present Alper Hankendi