Dart

Spry has five Dart-native targets. They share the same route pipeline and differ only in how the compiled server is delivered.

All targets generate source under .spry/src/. The exe, aot, jit, and kernel targets also compile it to a binary or snapshot under .spry/dart/.

Dart VM

BuildTarget.vm skips compilation entirely. Spry generates source files and the server runs directly with dart run.

import 'package:spry/config.dart';

void main() {
  defineSpryConfig(host: '127.0.0.1', port: 4000, target: BuildTarget.vm);
}

Output:

.spry/src/
  app.dart
  hooks.dart
  main.dart

Run:

dart run spry serve          # development
dart run .spry/src/main.dart # production

Best for local development and self-hosted environments where the Dart SDK is already present. Static assets are served from publicDir at the project root — run the binary from the project root to avoid path drift.

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Native executable

BuildTarget.exe compiles to a self-contained native executable. No Dart SDK required on the target machine.

import 'package:spry/config.dart';

void main() {
  defineSpryConfig(target: BuildTarget.exe);
}

Output:

.spry/dart/
  server     ← native executable
  public/    ← copied from publicDir

Run:

dart run spry build
./.spry/dart/server

The executable and public/ directory are everything you need to deploy. On Linux/macOS make sure the binary has execute permission (chmod +x .spry/dart/server). This is usually the right choice for Docker images and CI-produced release artifacts.

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AOT snapshot

BuildTarget.aot compiles to an AOT snapshot. Requires dartaotruntime on the target machine, but not the full SDK.

import 'package:spry/config.dart';

void main() {
  defineSpryConfig(target: BuildTarget.aot);
}

Output:

.spry/dart/
  server.aot
  public/

Run:

dart run spry build
dartaotruntime .spry/dart/server.aot

dartaotruntime must be from the same Dart release used during the build — version mismatches will fail at startup.

---

JIT snapshot

BuildTarget.jit compiles to a JIT snapshot. Requires the Dart VM but avoids re-parsing source on every startup.

import 'package:spry/config.dart';

void main() {
  defineSpryConfig(target: BuildTarget.jit);
}

Output:

.spry/dart/
  server.jit
  public/

Run:

dart run spry build
dart run .spry/dart/server.jit

---

Kernel snapshot

BuildTarget.kernel compiles to a kernel snapshot — the most portable Dart snapshot format. Runs on any compatible Dart VM regardless of platform.

import 'package:spry/config.dart';

void main() {
  defineSpryConfig(target: BuildTarget.kernel);
}

Output:

.spry/dart/
  server.dill
  public/

Run:

dart run spry build
dart run .spry/dart/server.dill

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Choosing a target

Target	Needs at runtime	Startup	Best for
vm	Dart SDK	Interpreted	Development, SDK-available hosts
exe	Nothing	Fastest	Docker, portable releases
aot	dartaotruntime	Fast	Cold-start sensitive, no full SDK
jit	Dart VM	Medium	Snapshot without AOT complexity
kernel	Dart VM	Slower	Maximum portability