gograph

Give Go coding agents a compiler-aware map for safer refactors.

gograph builds a local structural graph of your Go repository, with optional type-checked CHA/SSA enrichment. Its CLI and MCP workflows help coding agents trace callers and interface implementations, plan change impact, and enforce architecture without embeddings or a hosted code index.

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Static analysis; no target-code execution. Default indexing parses Go source locally and does not call application services. Descendant links and special files for extensions recognized by go/build are excluded, graph-directed source reads are confined to regular files beneath the analyzed repository, and linked/non-regular Go tool metadata (go.mod, go.sum, go.work, go.work.sum, and vendor/modules.txt) is rejected before toolchain invocation; an explicitly symlinked repository root remains supported. Applicable go.work use members must stay beneath the workspace directory, and each member directory, go.mod, and optional go.sum is validated before cmd/go starts. Gograph also reads project metadata such as .gitignore, graph/config JSON, and Git state. Indexing asks the installed Go toolchain for the effective build/module context; precise mode additionally performs package type loading, and doc runs go doc. Those operations follow your configured module/cache/network policy. Before repository package loading or go doc, applicable local module/workspace source trees are preflighted for links that cmd/go may inspect; .git and .gograph subtrees are excluded. Session telemetry is local under .gograph/sessions/; nothing is sent to gograph services.

Quick Start

# Install
brew install ozgurcd/tap/gograph
# or: go install github.com/ozgurcd/gograph/cmd/gograph@latest

# Build a type-enriched precise graph, then verify it
gograph build . --precise
gograph stats

# Start with repository-wide results that require no guessed symbol
gograph summary
gograph hotspot --top 5
gograph flow --no-tests

Homebrew and go install install the normal gograph CLI. MCP clients that support MCP Bundles can instead discover the local stdio server in the official MCP Registry as io.github.ozgurcd/gograph. Registry/MCPB installation is a separate distribution path; it does not install the Homebrew formula or configure the Claude Code marketplace plugin. The Registry is currently in preview. See Official MCP Registry and MCPB installation for client support, target selection, and current limitations.

Choose a real function or method shown by summary, hotspot, or gograph complexity, then substitute its name below:

gograph context "YourSymbol" # source + callers + callees + tests

# For compilable repositories, enrich the graph before a major refactor
gograph build . --precise
gograph plan "YourSymbol"

Build artifacts are written under the target .gograph/ directory. gograph adds .gograph/ to the enclosing Git repository root .gitignore when available, falls back to the build target .gitignore outside Git, and exits without replacing artifacts if no Go files are found or no source file parses successfully. The update accepts only an absent or regular .gitignore; a repository-provided link is refused and its target is not modified. Go build constraints, cmd/go package-directory rules, generated sources, module-mode ignore directives, and Git ignores use the same scanner policy for building, freshness checks, and change detection. Source-file symlinks and other non-regular .go entries are reported and excluded; linked/non-regular go.mod, go.sum, go.work, go.work.sum, and vendor/modules.txt entries are rejected before gograph or the Go toolchain reads them. Applicable go.work use members must remain beneath the workspace directory; their directories, go.mod, and optional go.sum are validated before cmd/go starts. .gograph itself must be a real directory, and graph.json must be a regular repository-confined file. Graphs with a missing or unsupported confinement policy marker must be rebuilt with the current binary before graph-backed commands use them. Older binaries do not enforce this boundary and should not be used to analyze untrusted repositories.

Each indexed source file stores a SHA-256 content digest. Rebuilds reparse all selected files in a changed package together and reuse parser records for unchanged packages; stats reports reused_files and rebuilt_packages. Precise builds reuse that AST work but still recompute repository-wide type/CHA/SSA enrichment so cross-package dispatch remains correct.

MCP refreshes stay in memory by default. To publish each successful refresh for CLI consumers and later server processes, start the server explicitly with:

gograph mcp . --persist-refresh

This opt-in mode writes or overwrites .gograph/graph.json and the nine Markdown reports after a confirmed-fresh refresh. It does not modify .gitignore, so ignore .gograph/ yourself before enabling it when needed. The directory holds only the latest published state; it is not a per-branch cache. If no usable graph exists (including an unsafe or unsupported artifact), the startup auto-build is published before serving; a failure there prevents startup. A later tool-triggered publication failure makes that tool return an error, and the server retries the pending publication on another refresh-capable call without rebuilding the already-fresh in-memory graph. Writers coordinate through a local .gograph/.artifacts.lock file; an existing lock entry must be regular rather than a link or special file. Reports are replaced first and graph.json is replaced last as the publication commit marker; the complete ten-file bundle is not a single atomic filesystem transaction. Same-directory replacement is atomic on Unix-like systems; Go does not guarantee atomic rename semantics on non-Unix platforms. The lock file remains as operational coordination state in addition to the ten outputs.

Why gograph?

Illustrative point-in-time output comparison from an earlier gograph revision (counts vary as the repository evolves; these commands return different kinds of evidence):

Key Features

61 Query, Analysis, and Workflow Capabilities — callers, callees, impact, context, plan, review, flow, errorflow, orphans, hotspot, coupling, and more. The MCP server registers 65 endpoints including four session lifecycle tools. Full command reference →

Native MCP Server — query, analysis, and workflow capabilities have MCP equivalents for Claude, Cursor, Copilot, and other MCP clients. Host/build operations (build, gate, snapshot, plugin/hook installation, server startup, help, and version) intentionally remain CLI-only, and transport-specific presentation differs where appropriate.

Explicit Freshness Model — CLI graph-backed analysis reads the last trusted persisted graph. gograph stale compares selected source content digests plus the effective build/module fingerprint; mtimes are diagnostic only for current indexes. It is a tri-state predicate in text and JSON modes: exit 0 means current, 2 means stale, and 1 means an operational or JSON serialization error; a missing or unsupported source-policy marker is an explicit status-1 rebuild requirement. MCP source-analysis tools check the same freshness per call, adopt a newer persisted precise graph, and incrementally rebuild changed package ASTs in memory using the latest requested analysis mode. MCP stale, default changes, and stats inspect the trusted persisted snapshot, or the startup auto-build fallback when no usable artifact exists. With --persist-refresh, that snapshot advances after a successful refresh, so default changes compares against the newly published state and normally no longer reports that refresh's source edits.

Compact Composite Workflows — context, plan, and explain combine source and graph evidence that would otherwise require several separate queries. Actual tool-call and token savings depend on the repository and task.

Narrow by Design — never runs target repository binaries or tests and does not intentionally scan .env, key, certificate, or credential files. Descendant links and special files for recognized Go build inputs are excluded; on-demand source and snippet reads use a repository-rooted filesystem handle and accept only regular .go files with