# Sdk Development > Working on the Rust, TypeScript, or MoonBit SDKs in sdks/. Use when modifying SDK code, adding SDK features, or testing SDK changes with the main Golem platform. - Skill: `golemcloud/sdk-development` (Agent Skill) - Install (CLI): `npx skillmds@latest add golemcloud/sdk-development` - Raw SKILL.md: https://api.skillmd.com/api/skills/golemcloud/sdk-development/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: golemcloud (https://skillmd.com/u/golemcloud) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/golemcloud/sdk-development --- # SDK Development The SDKs in `sdks/` are **not part of the main build flow** (`cargo make build` does not build them). Each SDK has its own build system and conventions. ## Rust SDK (`sdks/rust/`) ### Crates - `golem-rust` — Runtime API wrappers (transactions, durability, agentic framework, value conversions). Also re-exports the `#[derive(IntoSchema)]` / `#[derive(FromSchema)]` derives, which are defined by the root-workspace `golem-schema-derive` crate, not by `golem-rust-macro`. - `golem-rust-macro` — Procedural macros: `#[agent_definition]`, `#[agent_implementation]`, `#[tool_definition]`, `#[golem_operation]`, and the `MultimodalSchema`, `ConfigSchema`, `AllowedLanguages`, `AllowedMimeTypes`, and `ToolError` derives. ### Building ```shell cd sdks/rust cargo build -p golem-rust cargo build -p golem-rust-macro ``` ### Testing Tests use `test-r`. Library entry points call `#[cfg(test)] test_r::enable!();`. Integration-test entry points call `test_r::enable!();` at the top, and `test_r::test` must be in lexical scope for each `#[test]`. ```shell cargo test -p golem-rust cargo test -p golem-rust --features export_golem_agentic # Agent tests ``` ### Testing with the main platform ```shell # From the repository root, after building the test components needed by : cargo test -p golem-worker-executor --test integration -- --report-time ``` Use the `modifying-test-components` skill to build the selected test's WASM prerequisite. Run a worker-executor group or `cargo make worker-executor-tests` only for broad runtime, durability, value-conversion, or agent framework changes whose consumers cannot be isolated. ### Testing with golem-cli Set `GOLEM_RUST_PATH` to use local SDK in generated applications: ```shell export GOLEM_RUST_PATH=/path/to/golem/sdks/rust/golem-rust golem-cli app new my-test-app ``` ### Code style ```shell cargo fmt -p -- --check cargo clippy -p --all-targets -- -Dwarnings ``` ## TypeScript SDK (`sdks/ts/`) ### Prerequisites - Node.js - pnpm (managed via `packageManager` field) - `wasm32-wasip2`: `rustup target add wasm32-wasip2` (the Preview 3 wrapper still builds through this Rust target) - `wasm-rquickjs-cli`: `cargo install --locked wasm-rquickjs-cli@` (check `WASM_RQUICKJS_VERSION` in `.github/workflows/ci.yaml`) ### Packages Build order matters: `golem-ts-sdk` → `golem-ts-bridge` → `golem-ts-repl`. ### Building ```shell cd sdks/ts npx pnpm install npx pnpm run build ``` ### Testing ```shell npx pnpm --filter run test npx pnpm run test # All packages, for cross-package changes ``` Check the affected package's `package.json` before running a package test; for example, `@golemcloud/golem-ts-bridge` currently has no `test` script. ### Agent template WASM The agent template WASM embeds the existing `packages/golem-ts-sdk/dist/index.mjs`. Build that bundle before rebuilding the template whenever a change can affect the emitted runtime. Triggers include: - `wasm-rquickjs-cli` is updated - WIT dependencies change - any source or dependency in the Rollup graph rooted at `packages/golem-ts-sdk/src/index.ts` changes - wrapper generation or agent-template toolchain inputs change The filenames above are intentionally described by dependency graph rather than a fixed list: runtime modules can be added or reorganized. ```shell npx pnpm --filter @golemcloud/golem-ts-sdk run build npx pnpm run build-agent-template ``` The package build refreshes `dist/index.mjs`; `build-agent-template` then embeds it in the pre-compiled WASM. Running either command alone is not sufficient after a runtime change. ### Testing with the main platform ```shell # From repository root cargo make build-cli-test-bins-non-ci (cd sdks/ts && npx pnpm run build && npx pnpm run build-agent-template) # Build the specific test components required by . cargo-test-r run --package golem-cli --test integration -- --report-time --nocapture ``` Prefer targeted CLI integration filters that generate or exercise the affected SDK feature. They require fresh CLI binaries, SDK/template artifacts, and any selected test components. Use the full CLI suite only for broad template, bridge, REPL, or generated-application changes; after TS source changes, refresh the SDK/template first because `build-sdk-ts` skips when output files already exist. ### Testing with golem-cli ```shell export GOLEM_TS_PACKAGES_PATH=/path/to/golem/sdks/ts/packages npx pnpm install && npx pnpm run build # Build first! golem-cli app new my-test-app ``` ### Code style ```shell npx pnpm --filter run lint npx pnpm exec prettier --check ``` ## MoonBit SDK (`sdks/moonbit/`) See `sdks/moonbit/AGENTS.md` for full details. The MoonBit SDK has its own build system (`moon`) and code generation tools (`golem_sdk_tools`). ### Building ```shell cd sdks/moonbit/golem_sdk moon check --target wasm # Type-check moon build --target wasm # Build ``` ### Testing ```shell cd sdks/moonbit/golem_sdk ./scripts/run-sdk-tests.sh # For a narrower package/file check that does not need the JS runner: moon test --target wasm cd sdks/moonbit/golem_sdk_tools moon test ``` ### Regenerating WIT bindings ```shell cd sdks/moonbit/golem_sdk moon run script bindgen # Enforces the pinned Golem wit-bindgen and required post-processing moon info moon fmt ``` ### Code style ```shell moon info # Regenerate .mbti files when public interfaces changed moon fmt ``` ## Downstream Rebuild Requirements SDK changes can require rebuilding test components. This is the most common source of errors. ### Rust SDK change → test components 1. Build `golem-rust` / `golem-rust-macro` 2. Find Rust test components depending on the SDK: check `test-components/**/Cargo.toml` for `golem-rust` references 3. Rebuild each affected component following its `AGENTS.md` ### TS runtime/WIT change → test components 1. Build the affected TS SDK package and its required package dependencies (`npx pnpm run build` in `sdks/ts/` is the broad option) 2. Rebuild agent template WASM (`npx pnpm run build-agent-template` in `sdks/ts/`) 3. Find TS test components depending on the SDK 4. Rebuild each affected component following its `AGENTS.md` Type-only, test-only, documentation, bridge, or REPL changes that cannot affect `golem-ts-sdk/dist/index.mjs` or WIT do not require an agent-template rebuild. ## Test Process Ownership SDK unit tests and worker-executor tests must not invoke external tools or Golem binaries. Put tests that execute `golem`, `golem-cli`, `cargo`, `rustc`, `npm`, `npx`, `tsc`, `moon`, or another process in the CLI integration test suite. Build SDKs, generated code, templates, and test components as prerequisites before running unit or worker-executor tests. Non-CLI integration tests use `golem-test-framework` for process-backed dependencies and do not spawn additional processes directly. ## WIT Dependencies The Rust, TypeScript, and MoonBit SDKs covered by this skill have WIT files synced from the root `wit/` directory. **Never manually edit** their `wit/deps/` copies. ```shell # From repository root cargo make wit ``` ## Checklist 1. SDK code modified 2. SDK builds successfully 3. SDK tests pass 4. Agent template rebuilt from a fresh bundle (if TS runtime bundle or WIT inputs changed) 5. Dependent test components rebuilt (if any) 6. Platform tests that exercise changed SDK/platform integration pass 7. Affected SDK code is formatted and linted with its native tools 8. Full SDK/platform suites run only for broad or unclear impact