Supported languages

Languages are registered at compile time in a satisfies Record<LanguageId, LanguageProvider> table at packages/ingestion/src/providers/registry.ts. Omitting a registered language raises a build-time TypeScript error, so the table and this page cannot drift.

Registered languages (15 GA)

The LanguageId union has 16 entries because tsx is a separate provider-id. The GA count rounds to 15 — TSX is a flavour of TypeScript in every consumer-facing surface (@opencodehub/cli output, query filters, project_profile).

Language	tree-sitter parse	SCIP indexer
TypeScript	yes	scip-typescript
TSX	yes	scip-typescript (shared)
JavaScript	yes	scip-typescript (shared)
Python	yes	scip-python
Go	yes	scip-go
Rust	yes	rust-analyzer (stable)
Java	yes	scip-java
C#	yes	scip-dotnet
C	yes	scip-clang
C++	yes	scip-clang
Ruby	yes	scip-ruby
Kotlin	yes	scip-kotlin
Swift	yes	—
PHP	yes	—
Dart	yes	—

COBOL is also indexed (regex hot path; the cobol provider is a stub). Add --allow-build-scripts proleap to opt into the JVM ProLeap deep-parse.

Native bindings and the WASM default

The default parse runtime on Node 22 and Node 24 is web-tree-sitter (WASM). It has no native ABI dependency, so it works on every supported Node version out of the box.

The native tree-sitter N-API addon is available as an opt-in path on Node 22, where it is measurably faster on large repos. Enable it with the env var or CLI flag:

opt into native parsing on Node 22

OCH_NATIVE_PARSER=1 codehub analyze
# or
codehub analyze --native-parser

Native is unavailable on Node 24 until node-tree-sitter@0.25.1 lands on npm (tree-sitter/node-tree-sitter#276). Kotlin, Swift, and Dart ship their grammars as .wasm blobs vendored at packages/ingestion/vendor/wasms/ regardless of the runtime selection — those grammars do not have prebuilt N-API addons on npm.

The complexity-metrics ingestion phase still uses native tree-sitter for cyclomatic-complexity counting. On Node 24 (or Node 22 without the opt-in) it degrades with a one-shot stderr warning; all other parsing continues via WASM.

ADR 0013 (docs/adr/0013-parse-runtime-wasm-default.md) explains the rationale.

Adding a language

Four steps, all committed together:

1. Pin the tree-sitter grammar in packages/ingestion/package.json.
2. Implement LanguageProvider in packages/ingestion/src/providers/<lang>.ts.
3. Add the entry to the registry in packages/ingestion/src/providers/registry.ts — TypeScript fails the build if the key is missing.
4. Add fixture tests under packages/ingestion/test/fixtures/<lang>/, using the parseFixture helper from test-helpers.ts.

See adding a language provider for the full walkthrough.