English documentation · runtime 7.24.4 · SDK 2.6.7. Content is maintained with runtime development; see each guide's scope and review date.

TypeScript native support

Status: Active in source; packaged runtime release pending Scope: current-state source toolchain and language service Last reviewed: 2026-09-14 Owner: AX Code maintainers

AX Code uses the official Go-based TypeScript 7.0.2 compiler for workspace checks, SDK emission, and its built-in JavaScript/TypeScript language server. The language server runs the shipped native executable directly with --lsp --stdio. It does not invoke a registry runner or download a floating language-server version. No Go toolchain is required to use AX Code.

Install dependencies with pnpm install, including optional dependencies. The native compiler needs its matching OS/CPU package. Standalone builds stage and verify that package before delivery. A missing or mismatched binary produces an actionable error instead of silently starting a JavaScript server.

Compiler API compatibility

The workspace pins @typescript/native to npm:typescript@7.0.2 and keeps typescript aliased to npm:@typescript/typescript6@6.0.2 for tools that import the legacy JavaScript Compiler API. Type checks and SDK emission use the native compiler. The compatibility API is not the default language server.

Framework tooling for Vue, Svelte, and Astro uses its own server integration; TypeScript library compatibility does not establish compiler-plugin support. SolidJS JSX transformation continues through Babel. Runtime tests and emitted artifacts must pass independently of a successful type check.

Diagnostics and memory

Native TypeScript uses pull diagnostics. AX Code requests them when a caller asks to wait for diagnostics or collects the diagnostic inventory. Synchronizing a file alone does not wait for type checking. Edits invalidate dependent cached results; stale, pending, or failed inventories are reported as partial/degraded by the aggregated diagnostics API. A successful pull refreshes that file. Server refresh requests mark cached results stale; the next diagnostic request refreshes them on demand. Background server traffic does not renew the idle lifetime. File edits can still refresh previously requested documents in the background. The raw record API refreshes stale results within a bounded collection budget and rejects incomplete inventories; edit tools disclose this condition without losing the successful file edit. Other language servers retain their existing push diagnostics behavior.

Overlapping explicit diagnostic waits for the same file share a request only within the same workspace generation. Sequential requests still refresh; a workspace change prevents reuse of an older in-flight request. Background and inventory refreshes recheck freshness after waiting for a document lock.

Successful patch deletions and moves close the removed source documents in the language service. Failed patch transactions retain their document state. Cleanup has a shared two-second deadline and skips paths recreated by a later operation in the same patch. Incomplete cleanup is disclosed without undoing saved edits. If delivery to the server times out, diagnostics remain incomplete until that client restarts.

Idle language servers are reclaimed after 30 minutes in the normal memory profile, or five minutes with AX_CODE_MEMORY_PROFILE=low. Reclamation runs on the existing one-minute health-check interval and waits for active and queued requests to settle. Servers restart on demand. AX_CODE_LSP_IDLE_MS overrides the idle duration in milliseconds; 0 disables idle reclamation. Invalid values use the profile default. These settings do not impose a process RAM ceiling or a machine-wide budget. Speculative prewarming remains opt-in.

Reclaiming a server discards its diagnostic inventory. Aggregated results remain marked degraded until previously open documents have been reopened and checked, or explicitly removed. The raw inventory API rejects incomplete coverage. The coverage ledger is limited to 2,000 paths; overflow remains conservatively incomplete until the project instance is disposed. Reclaiming an empty server loses no coverage. Edit tools preserve saved changes and disclose that diagnostics are incomplete. Use a full project type check to establish whether the project is clean.

Native compilation does not guarantee a particular resident-memory reduction. Compare the same project, open documents, requests, and process-tree RSS before making a memory claim.

Explicit server override

An existing trusted lsp.typescript.command configuration still overrides the built-in native server. For a legacy server, install and pin the server and its compatible TypeScript SDK in the project, then set command to that installed executable with --stdio. Avoid unpinned npx commands. The override is explicit; AX Code does not automatically fall back when the native compiler is unavailable.

Upstream: TypeScript 7 announcement.

TypeScript 7.0.2 saved-document compatibility

The native 7.0.2 server can return an earlier diagnostic snapshot when file-watch traffic overlaps saved edits. AX Code closes and reopens changed documents for that exact server version before requesting diagnostics. One bounded document query flushes the deferred close before reopening; other queries wait for this replacement. This sends the full changed document; unchanged documents still reuse overlapping requests. Other server versions keep their negotiated synchronization mode. An interrupted replacement remains incomplete until the language server restarts.