Learn / Code graph

What is a code graph?

A code graph is a structured representation of a codebase where functions, types, and modules are nodes, and relationships — calls, imports, dependencies, effects — are edges. Instead of reading files one at a time, a tool or AI agent queries the graph: who calls this, what does it touch, what breaks if it changes.

Also called:code intelligencecode knowledge graphcodebase indexingstatic analysis graphblast radius analysisimpact analysis for codesemantic code searchrepository context for AI agentscodebase context engineAI agent code understanding

Why AI agents need one

Coding agents burn most of their context window reading files to rebuild an understanding that existed the last time someone — or something — analyzed the repository. A code graph makes that understanding persistent and queryable, so the agent asks a targeted question and receives a compact, structured answer instead of raw source.

The practical effect is fewer tokens spent orienting and more spent working, with answers — callers, dependencies, tests, contracts — that are computed rather than guessed.

Blast radius: the killer query

The question every engineer asks before a risky change — what does this touch? — becomes a computable answer: the transitive set of code affected through calls, contracts, shared state, and history. Severity-ranked impact turns 'I think it's safe' into a checked claim.

From ClassEve

Context Zero Engine indexes a repository into a PostgreSQL-backed code graph and serves symbols, effects, contracts, similar code, and blast radius to AI agents over MCP and HTTP — entirely on your machine.

Context Zero Engine — local code graph for agents

Code graph · FAQ

Common questions.

How is a code graph different from grep or text search?

Text search finds strings; a graph knows structure. Grep can find the words 'calculateTotal' — the graph knows which of those are the definition, which are calls, what the callers are, and what depends on the result.

Does building a code graph send my code to the cloud?

Not necessarily — and for private code it shouldn't. Local-first engines index and serve entirely on your machine. ClassEve's Context Zero Engine, for example, runs against a local PostgreSQL database; nothing leaves the machine.

Compared head to head

Context Zero Engine vs. Context7