dsh-plugin-codegraph

dsh-plugin-codegraph

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Structural code intelligence for DeepSeek Harness (dsh).

Gives the agent two tools — codegraph and codegraph_index — so it can ask where is this declared, who calls it, what breaks if I change it, and how does one symbol reach another, answered from a pre-built index instead of from text search.

dsh plugin --profile <name> add dsh-plugin-codegraph

Why

An agent editing code asks structural questions before it touches anything. The tools it usually has answer them badly or not at all:

• grep matches a name inside comments, strings, and unrelated identifiers, and cannot answer "who calls this" at all.
• LSP answers precisely, but needs a running server per language, a warm workspace index, and a cursor position rather than a name.

A symbol graph answers all of it from one cheap lookup. This plugin ships both halves: a store that serves queries from an on-disk graph, and an indexer that builds one, so a fresh workspace needs no external tooling.

What the model gets

Two tools, deliberately separate.

codegraph — ten read-only operations

Operation	Answers	Required
search	Where is a symbol declared?	query
node	One symbol with its immediate callers and callees	symbol
callers	What calls this?	symbol
callees	What does this call?	symbol
impact	What can a change to this reach?	symbol
trace	How does one symbol reach another?	from, to
files	What is indexed, under a directory or glob?	—
status	How large and how fresh is the index?	—
explore	Several related declarations with their source	query
context	Everything relevant to a task	task

codegraph_index — build or refresh the graph

Separate from codegraph rather than an eleventh operation, because indexing a large workspace takes minutes while a query takes milliseconds, and a tool's timeout budget is fixed per registration. Folding them together would force one budget that is either too tight for a real build or too loose to catch a hung query.

Indexing is always explicit. No query ever triggers it implicitly: a callers call that silently took four minutes would be indistinguishable, to the model, from a hung tool.

When no index exists, status answers plainly rather than failing — it says there is no index and names codegraph_index as the fix. Every other operation fails loudly instead, so an unindexed workspace is never mistaken for an empty one.

Interoperability with the codegraph CLI

The on-disk format is not ours. This plugin reads and writes schema version 4 at <projectRoot>/.codegraph/codegraph.db — the same path and format that @colbymchenry/codegraph writes.

That means:

• Already using the codegraph CLI? Its index is picked up as-is. Mount the plugin, skip codegraph_index entirely, and query.
• Indexed with this plugin? The CLI still reads it.
• There is never a second, disagreeing graph for one workspace.

Why not just spawn the CLI

A plugin can wrap @colbymchenry/codegraph's own CLI instead of reimplementing the store and indexer: spawn it as a subprocess, expose each of its commands as a separate tool, done in an afternoon. This plugin chose not to, for three concrete reasons:

• No second thing to install. Shelling out to a CLI means the host needs that binary on PATH, at a version the plugin was actually tested against — an extra install step, and an extra way for the two to drift out of sync. npm install is the whole story here; the indexer and store run in-process.
• Fewer tools, not more. Every tool's schema rides along in the system prompt on every turn, whether or not it gets called that turn. Ten single-purpose tools (one per CLI subcommand) cost more of that budget, every turn, than the two this plugin exposes — codegraph's operation field is a dispatch, not a compromise.
• No incremental reparse, on purpose. "Sync only the changed files" sounds obviously faster, but the rule this graph resolves calls by — one unique name wins workspace-wide — is global: adding a symbol in file A that collides with one already indexed from file B should invalidate edges that point at B, even though B never changed. A parser that reparses only the touched files and patches in their own new edges has no way to notice that. codegraph_index always rebuilds the whole graph instead — cheaper to reparse everything than to get that invalidation wrong — leaving incremental reparse as a future optimization only once it's an actual, measured bottleneck, not a default.

Language coverage

The bundled indexer parses TypeScript, TSX, JavaScript, JSX, Python, Go, Java, C, C++, C#, PHP, Rust, Ruby, Zig, Kotlin, Swift, Dart, and Scala. Grammars load lazily — one per language, on first sight of a matching file — so a Go-only workspace never loads a Python grammar.

The store is format-bound, not language-bound: a graph built by the codegraph CLI over languages this indexer does not parse is still fully queryable. If you need broader indexing coverage today, index with the CLI and query through this plugin.

Call resolution never guesses

Every call site resolves in a fixed order: an import that lands on an indexed file wins; otherwise a unique workspace-wide name wins; otherwise no edge is emitted and the site is recorded as unresolved.

That last rule is deliberate. The model acts on callers output, so a confidently wrong caller sends it to edit the wrong file, while a missing caller merely sends it back to text search. The index report's unresolved_count is not, by itself, that gap's size — a type-free resolver was never going to settle a member call (x.map()) or a name already imported from elsewhere, and those dominate the total in a typical workspace. unresolved_likely_internal_count is the subset worth judging completeness by: bare, undeclared names that were structurally plausible workspace calls.

Install

dsh plugin --profile <name> add dsh-plugin-codegraph

That one command is the whole install: it fetches the package and reconciles the profile's manifest for you, appending dsh-plugin-codegraph to dsh.profile.bundles. There is no JSON to edit by hand. Afterwards, $DSH_HOME/profiles/<name>/package.json — $DSH_HOME defaults to ~/.dsh — reads like this, shown here so you can check it rather than write it:

{
  "dsh": {
    "profile": {
      "bundles": ["@deepseek-ai/dsh-base", "dsh-plugin-codegraph"]
    }
  }
}

To confirm the four plugins mounted without spending an API key, run dsh --profile <name> --dump-default-config; they appear grouped under a # == dsh-plugin-codegraph heading.

The bundle mounts all four plugins in one layer. Retune any of them from the profile's own cordis.patch.yml, addressing rows by the ids the bundle declares (codegraph, codegraph-sqlite, codegraph-tree-sitter, codegraph-tool):

- id: codegraph-tree-sitter
  config:
    languages: ['typescript', 'tsx']
    exclude: ['node_modules', 'dist', 'vendor']
    respectGitignore: true
    watch: true # the default; shown for clarity — set false to keep indexing purely explicit

- id: codegraph-tool
  config:
    maxLimit: 50
    indexTimeoutMs: 600000

Packages

Installing the bundle is enough; these are listed for anyone composing by hand.

Package	Role
dsh-plugin-codegraph	The bundle — depends on the four below and ships the patch layer
dsh-plugin-codegraph-service	Service Definition: ctx.codegraph, the provider registries, the query vocabulary
dsh-plugin-codegraph-sqlite	Service Provider: read-only SQLite store over the on-disk graph
dsh-plugin-codegraph-tree-sitter	Service Provider: the tree-sitter indexer that writes that graph
dsh-plugin-codegraph-tool	Consumer: the model-facing tools, their bounds, and their rendering

The split is not ceremony. The seam carries no source text and performs no filesystem access, so a store needs no filesystem capability at all; retrieving a declaration's code composes a graph query with a ctx.fs read in the consumer, which is the only role that can reach a remote workspace's files.

Known limits

• Watching is on by default, and self-limiting where it wouldn't help. A successful codegraph_index starts watching that root automatically — a single recursive fs.watch on macOS/Windows, one inotify watch per directory on Linux — refreshing the index after a debounced quiet period. Set watch: false to keep indexing purely explicit instead. It's overridden back off on a WSL2 kernel watching a path mounted in from the Windows host (/mnt/<drive>/...), since inotify doesn't reliably deliver events over that mount; CODEGRAPH_FORCE_WATCH=1 and CODEGRAPH_NO_WATCH=1 override that default either way. Whether or not watching is on, status still reports how many indexed files have gone stale — modified or removed since the last run — found by statting the filesystem directly, so a caller can always tell a trustworthy index from a drifted one instead of assuming the best.
• Git hooks and worktree detection ship as library functions only — installGitHooks/uninstallGitHooks (a post-checkout/post-merge/post-commit/post-rewrite hook running a command of your choosing, for environments where live watching isn't available) and detectWorktree (whether a root is a linked git worktree, and where its main repository lives). Neither is wired into plugin load or exposed as a model-visible tool: .git/hooks/* is shared, ambient state this package doesn't own, so installing it is left to a caller's own init script, never automatic.
• Exclusion unions the built-in default directories with the project's own .gitignore. Build output that lands outside node_modules/dist/build/coverage (a lib a TypeScript project compiles to, say) is almost always gitignored too, and indexing it alongside its own source would hand call resolution two same-named declarations of one symbol to pick between arbitrarily. Only a practical subset of gitignore syntax is understood — no **, character classes, or per-directory .gitignore files. Turn it off with respectGitignore: false.
• The unresolved tail can be large, and most of it is not a gap. unresolved_count includes every member call and already-imported name a type-free resolver could never have settled; unresolved_likely_internal_count is the narrower number that reflects re-exports and dynamic dispatch the graph actually missed.
• context ranks by identifier-term overlap, so a task phrased without naming any symbol ranks poorly. There is no semantic matching.
• dsh itself is in developer preview and iterating fast; expect compatibility-breaking changes.

Credits

The on-disk graph format — schema version 4 at .codegraph/codegraph.db — originates with @colbymchenry/codegraph (MIT), a local-first code-intelligence tool for AI agents. This plugin adopts that format deliberately so the two remain mutually readable; the indexer, store, and tool here are independent implementations written against the DeepSeek Harness plugin model.

Built on DeepSeek Harness and Cordis.

Feedback

Questions or need support? Open an issue.

License

MIT