cndb — ContextDB

A single-file, embedded graph knowledge base for codebases.

cndb reads a repository, extracts its structure into a graph of symbols and relationships, and stores it in one portable .cndb file. Coding agents and applications query that graph to answer structural questions about code — who calls this, what breaks if I change it, what do I need to read to understand this subsystem — without crawling the filesystem.

cndb is a storage engine in its own right, an alternative to SQLite rather than a layer on top of one. No server, no daemon, no network protocol, no third-party database underneath.

• One file. The entire graph lives in a single .cndb file you can copy between machines.
• Local-first. Runs in-process with zero runtime dependencies. Source code never leaves the machine.
• Deterministic. Structure is extracted with tree-sitter, so the same commit produces the same graph on every machine. Heuristically resolved edges are tagged as such rather than reported as fact.
• No MCP. Applications get real in-process function calls. Agents shell out to one static binary that prints JSON — no server to register, no port, no editor restart.

cndb init                      # build the graph for this repo
cndb sync                      # incremental re-index of changed files
cndb explore "auth flow"       # relevant symbols, with call paths and snippets
cndb callers parse_header      # who calls this
cndb impact parse_header       # blast radius of a change
cndb path handle_request write_record

let db = Cndb::open(".cndb/graph.cndb")?;
let callers = db.callers("cndb::storage::append_record", Depth(2))?;

Early development. M1, the storage core, is implemented: the .cndb file format, the append-only record log, the document offset map, the BSON codec, and crash-safe commit and recovery.

let mut db = cndb::Cndb::open("graph.cndb")?;
let id = db.insert(&json!({ "kind": "Function", "name": "parse_header" }))?;
db.commit()?;
assert_eq!(db.get(id)?["kind"], "Function");

The graph model, extraction, query engine, CLI and bindings follow in M2–M6. See docs/ARCHITECTURE.md for the full design, the file-format specification and the roadmap.

Apache-2.0. See LICENSE.