dsh-plugin-codegraph
English | 中文
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 |
The tool also reports its own state into the system prompt. Every prompt assembly carries one line describing the workspace's index — how many files, declarations and relationships it holds, when it was built, and how many generated artifacts were left out — or, when there is none, that codegraph_index has to run first. That line is a section whose text is a function, re-evaluated per request by the host; nothing is spent on a status round-trip to learn it.
Re-indexing parses only what changed. Every successful run leaves the extraction it produced for each file in .codegraph/cache/; the next run — a second codegraph_index, or a watch rebuild after one edit — confirms each file by its recorded modification time and size and reuses its extraction instead of reading and parsing it again. On a 337-file workspace measured here, a repeat run cost 45 ms against 991 ms for the first. Edges and call resolution are still rebuilt over the whole graph every time, deliberately: the rule that resolves a call by a workspace-unique name is global, so a symbol added in one file can invalidate edges pointing at another that never changed. cacheVerify: 'hash' trades that speed for correctness when a checkout can restore an older file without moving its mtime.
A large workspace indexes in the background. codegraph_index estimates the job from the previous run's summary: at or past backgroundIndexThreshold files it hands the run to the host's job registry and returns a job id immediately, instead of holding a tool call open for minutes. job_output <id> reads the report; job_kill <id> stops it. Small workspaces keep the synchronous path, so the common case never pays for a job round-trip. Set backgroundIndex: true or false to override the estimate.
A new session starts with an index. When an agent is created for a workspace that has no index yet, the plugin starts one in the background through the host's job registry, so the first structural question already has a graph to answer from instead of spending three round trips on status → codegraph_index → retry. A workspace that already has an index is left alone (the watcher maintains it), and a host without a job registry skips the auto-build rather than blocking session creation.
Chinese task descriptions get English candidates. context ranks by identifier overlap, and a task written in Chinese names no identifiers — measured on a React admin workspace, 「修改报表页的分页与筛选参数」 returned nothing at all. A built-in table now maps frequent Chinese development words to identifier candidates (报表 → report, 分页 → page/pageSize/pagination, 筛选 → filter/search, …) and appends them after the literal terms; the same task now leads with report, page, filter, param. contextSynonyms extends the table per deployment.
It says so, once, when the registry has a newer release. A plugin cannot upgrade itself — it lives in a profile's dependency tree, and rewriting that tree is the host's job. So it does the next best thing: after one of its tools runs, it checks the registry in the background and, when the published version is newer than the running one, appends a notice to the next step of the conversation, where both the model and the user can see it. Three details keep it from turning into noise: the check only ever happens after a tool was used, so nothing arrives out of nowhere; a release is announced once, with notifiedVersion persisted so a desktop restart does not replay it; and checks run at most every six hours, while an unreachable registry, a timeout, or an unwritable state file all mean "nothing to report" rather than an error. The registry follows npm's own resolution order — npm_config_registry, then registry= in the user's ~/.npmrc, then npm's public default — so a machine behind a mirror checks the mirror it actually installs from. updateCheck: false turns the whole thing off, and updateCheckIntervalMs changes the interval.
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.
- The parse cache is incremental; the edges are not. "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. So this plugin splits the two: each file's extraction is cached and reused (991 ms → 45 ms on a 337-file workspace), while edges are rebuilt over the whole graph on every run. Reparsing everything was the wrong thing to save; re-resolving everything is cheap.
Language coverage
Eighteen languages, all bundled — no per-language setup, and grammars load lazily, so a Go-only workspace never pays for the Python one.
| Language | Extensions | Language | Extensions |
|---|
| TypeScript | .ts .mts .cts | C | .c .h |
| TSX | .tsx | C++ | .cpp .cc .cxx .hpp .hh .hxx |
| JavaScript | .js .mjs .cjs | C# | .cs |
| JSX | .jsx | PHP | .php |
| Python | .py .pyi | Rust | .rs |
| Go | .go | Ruby | .rb |
| Java | .java | Zig | .zig |
| Kotlin | .kt .kts | Swift | .swift |
| Dart | .dart | Scala | .scala .sc |
The store is format-bound, not language-bound: a graph the codegraph CLI built over languages this indexer does not parse stays fully queryable. For anything outside the table above, index with the CLI and query through this plugin.
Auto-indexing
Three things keep the graph current without you asking:
- A new session starts with a current index. Open a session in a workspace that has never been indexed — or whose index is more than ten minutes old — and the plugin starts a background build for it. That refresh is also what restarts the file watcher after a host restart, since watching only begins once a successful index has established a baseline; without it a restarted host would sit on the previous process's graph indefinitely.
- Watching is on by default. Every in-scope directory is watched through the host's filesystem seam, and a debounced change triggers a rebuild. An empty change set schedules nothing, so the plugin's own
.codegraph writes never loop.
- Re-indexing parses only what changed. Each run persists its per-file extraction; the next one confirms each file by mtime+size (or a SHA-256, under
cacheVerify: 'hash') and reuses it. Measured on a 337-file workspace: 991 ms for the first run, 45 ms for every run after — and a watch rebuild after one edit costs about the same as reusing everything else.
Two more things keep it correct rather than just current: committed build output (a checked-in dist/ tree) is skipped by shape so its mangled names never pollute resolution, and a large workspace's first index moves to a background job instead of holding a tool call open.
What this plugin adds
Five things you do not get from a CLI an agent shells out to:
- No second runtime.
dsh plugin add dsh-plugin-codegraph is the whole install — no binary on PATH, no MCP server to wire, no version to keep in sync with the plugin.
- An index that starts itself. Opening a session in an unindexed workspace builds one in the background, and every change after that is picked up by a watcher.
- A model that knows the state of what it is querying. Every request's prompt carries how large the index is, when it was built, and how many generated files were skipped — for free, instead of a
status round-trip.
- Entry points for a human.
/codegraph status|index|files, and a settings panel with a rebuild button. Neither spends a model turn.
- Re-indexes that are cheap. A parse cache makes a repeat run 991 ms → 45 ms on a 337-file workspace, so "just re-index before you answer" stops being an expensive habit.
Compared with the codegraph CLI
The CLI is the origin of the on-disk format this plugin reads and writes, and it covers more languages than this indexer parses. They are aimed at different things:
| This plugin | @colbymchenry/codegraph |
|---|
| Shape | A DSH plugin: two tools, a /codegraph command, a settings panel, and a prompt section | An MCP server plus a CLI you install and wire into each agent |
| Install | dsh plugin add dsh-plugin-codegraph — no second runtime, no MCP config | Install the CLI, run its setup to wire the MCP server per agent, then codegraph init per project |
| First index | Automatic: opening a session in an unindexed workspace starts one | Explicit codegraph init per project |
| Index state | One line in the prompt on every request (size, age, skipped artifacts) plus a settings panel | Ask its MCP tool |
| Re-index cost | Parse cache — 991 ms → 45 ms on a 337-file workspace | Not measured here |
| Background indexing | Past ~1000 files the run becomes a ctx.jobs job | Not measured here |
| Committed bundles | Skipped by shape (.min., or an average line > 500 chars) | Not measured here |
| Languages | 18 bundled grammars | 40+, including ArkTS, Vue, Svelte, Solidity, Terraform |
| On-disk format | Schema v4 — the CLI's own path and format | Schema v4 (origin) |
What this plugin adds is not a better graph — it is the same graph, delivered where DSH can act on it: no second process, no MCP plumbing, a state line the model reads for free, a human command, and a UI.
The Rust engine
Parsing was the one place this plugin was visibly slow, and the reason was structural: parse plus extractFile ran on the host's main thread through web-tree-sitter, one file at a time. A native addon now does that work instead — tree-sitter compiled into Rust, one worker per core through rayon — and it is on for TypeScript, TSX, JavaScript and JSX already.
| JS + WASM | Rust addon |
|---|
| parse + extract (336 files, same input) | 727 ms | 110 ms |
| whole walk, 337-file workspace (median of 4) | 807–886 ms | 277–336 ms (2.6–2.9×) |
The whole-walk number is lower than the engine number because the walk is not only extraction: reading files, hashing, caching decisions and the final write are unchanged, and three files in that workspace would need the JS engine anyway (below). On a workspace with no such files the gap widens.
Three details worth knowing:
- It is optional, and it degrades quietly. The addon ships as
.node platform artifacts; if it is missing, unbuilt, or throws, every file falls back to the JS extractor. engine: 'js' forces that path, 'auto' (default) uses the addon where it can.
- The rule table is not duplicated. The addon receives
LANGUAGE_TABLE as JSON and builds its matchers from it, so the two engines cannot drift on what a rule says — only on how well they implement it, which is what the parity tests measure.
- Files whose parse tree has errors are left to the JS engine. The two grammars (WASM 0.20 vs crate 0.23/0.25) recover from malformed input differently — on a real workspace that showed up as one phantom definition and a line off by one — so the addon refuses those files and
walk extracts them the old way. Correct over fast.
It no longer freezes the host. Before 0.6.0 extractWorkspace was a synchronous export: the napi call waited on the whole batch on the JS thread, and rayon only made that wait shorter, never optional. Auto-indexing runs inside the renderer, so that wait was the whole UI — opening a historical conversation could take the desktop down, and a sample of the main thread put 2415 of 2415 frames in uv_fs_stat at 47% CPU. The call is an AsyncTask now: the work goes to libuv's thread pool and the caller awaits a promise. Across one 1480-file, 644 ms call the event loop ticked 53 times, worst delay 12 ms.
The binaries now arrive with npm. Five platform packages (dsh-plugin-codegraph-indexer-*) are published as this package's optionalDependencies, and npm's os/cpu fields pull exactly the one this machine can dlopen — no more copying a .node into the package by hand. When it cannot be had (a pruned install, a mirror missing the package, an unsupported platform) the JS path still answers.
packages/tree-sitter/tests/rust-parity.spec.ts asserts the two engines produce byte-identical extractions on every fixture, and on a real workspace when CODEGRAPH_PARITY_WORKSPACE is set.
Coverage and next. Four languages today. Python, Go, Java, C/C++, Rust, C# and the rest still go through the JS extractor, which keeps working unchanged; each new language needs its own Rust-side special cases plus a parity run before it ships. The five-platform binaries are built by the build-native matrix in .github/workflows/publish.yml; the build details — especially the npx -p @napi-rs/cli napi invocation and the toolchain traps — live in crates/indexer-rust/README.md.
Call resolution never guesses
Every call site resolves in a fixed order: an import that lands on an indexed file wins; otherwise a declaration in the calling file itself wins when exactly one carries the name — lexical scope settles it before the workspace gets a say, which is what keeps a helper declared in two test files, or a render in two components, from being counted as ambiguous; otherwise a unique workspace-wide name wins; otherwise no edge is emitted and the site is recorded as unresolved.
The same-file tier applies to bare calls only. A member call (x.map()) names a property of a receiver this resolver cannot type, so letting a same-named local declaration win it would be a guess, not a scope resolution.
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.
Command and panel
Two human-facing surfaces over the same index, for when you would rather not ask the model:
/codegraph [status|index|files <pattern>] — report the current workspace's index, rebuild it, or list indexed files. status is the default.
- Settings → 代码图谱 — a panel showing the workspace's index state (files, declarations, relationships, unresolved counts, when it was built, how many generated artifacts were skipped), with a path box and a rebuild button. Its data comes from the plugin's own
/dsh-plugin-codegraph/api/state and /api/reindex endpoints, which read nothing but <root>/.codegraph/status.json and never expose arbitrary files.
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
skipMinified: true # the default; set false to index committed bundles anyway
engine: auto # auto | js | rust — prefer the native addon where it applies
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.
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 it goes through the host's filesystem seam. A successful
codegraph_index starts watching that root automatically: one watch per in-scope directory, opened through ctx.fs.watch rather than node:fs directly, so a workspace a backend serves from another execution world is watched where it actually lives. The seam's change callback carries no filename, so a rebuild is triggered by re-listing the watched directories and diffing them against the previous snapshot; an empty diff schedules nothing, which is what keeps the indexer's own .codegraph writes from rebuilding forever. A backend that cannot watch degrades to explicit indexing with a logged reason instead of failing the plugin. 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.
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
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License
MIT