Native TypeScript Workflows

A3S Flow is a Rust SDK. NativeTsRuntime is an optional runtime adapter for hosts that want workflow authors to write TypeScript while Rust still owns run creation, event storage, replay, workers, scheduling, and inspection.

This is not a standalone TypeScript SDK. TypeScript source is compiled into a native artifact and invoked through a versioned JSON protocol.

Compiler Contract

NativeTsRuntime expects a compiler executable with this command shape:

a3s-flow-native-compiler compile <entrypoint.ts> -o <artifact>

The produced artifact must:

• be executable by the host,
• accept --a3s-flow-runtime,
• read one NativeRuntimeRequest JSON object from stdin,
• write one NativeRuntimeResponse JSON object to stdout,
• dispatch workflow requests to the configured export,
• dispatch step requests by payload.step_name.

Configure The Runtime

use a3s_flow::{NativeTsRuntime, NativeTsRuntimeConfig};

let runtime = NativeTsRuntime::new(NativeTsRuntimeConfig::new(
    "/path/to/a3s-flow-native-compiler",
    ".a3s/flow/native-ts",
    ".",
));

Examples can also read the compiler path from the environment:

A3S_FLOW_NATIVE_TS_COMPILER=/path/to/a3s-flow-native-compiler \
  cargo run --example native_ts_greeting

A3S_FLOW_NATIVE_TS_COMPILER=/path/to/a3s-flow-native-compiler \
  cargo run --example native_ts_preflight

When that variable is not set, the examples print the missing prerequisite and exit successfully so normal Rust example suites remain portable.

Preflight

Call preflight(&spec) when a host wants early validation:

let preflight = runtime.preflight(&spec).await?;

println!("entrypoint={}", preflight.entrypoint.display());
println!("artifact={}", preflight.artifact.display());
println!("source_hash={}", preflight.source_hash);
println!("cache_hit={}", preflight.cache_hit);

Preflight validates the spec, resolves the entrypoint, hashes the source and runtime identity, compiles only on a cold artifact cache, and surfaces compiler stderr as a runtime error when compilation fails.