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.

Parse runtime — WASM-only

The parse runtime is web-tree-sitter (WASM) on Node 20, 22, and 24. WASM has no native ABI dependency, so it works on every supported Node version out of the box and npm install -g @opencodehub/cli@latest does zero native builds.

All 15 GA grammar .wasm blobs are vendored at packages/ingestion/vendor/wasms/, built from the grammar sources pinned in package.json. Re-vendoring is a one-shot operation via bash scripts/build-vendor-wasms.sh; consumers never build grammars at install time.

The complexity-metrics ingestion phase is also WASM-backed, so cyclomatic-complexity counting runs on every install instead of degrading to a no-op.

ADR 0015 (docs/adr/0015-wasm-only-parser-at-the-npm-distributed-boundary.md) explains the rationale and the bulletproof-install plan; ADR 0013 records the prior WASM-default + native-opt-in posture and is now superseded.

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.