Syntac

Syntac is a local-first Android coding agent by DraxonV1.

Open a project folder on your phone, connect an AI provider, chat about code, inspect file changes, run commands, and keep project state on-device.

In development right now, expect issues & bugs. Report issues at /issues.

• Developer: DraxonV1
• Repository: https://github.com/DraxonV1/Syntac
• Android package: com.syntac
• Current version: 0.1.1-beta.6 (versionCode 16)
• Default update channel: beta

Overview

Syntac is built for code work away from a laptop. It gives one Android app enough local context to review a project, ask an AI model for changes, inspect generated edits, and run command-line checks through an Android runtime.

Core behavior:

• Project folders stay on your device.
• Chat history and tool results stay on your device.
• API keys and OAuth credentials stay in Android secure storage.
• Model requests go only to the provider you configure.
• Shell commands run only for the active project.

Main features

• Local project browser with recent projects and search.
• Chat-based coding agent with streaming responses.
• File tools for reading, writing, patching, globbing, listing, deleting, and searching project files; explicit read-only systemwide diagnostics.
• Bash and durable runtime job tools through packaged Android runtime or Termux bridge.
• Provider support for Google Antigravity / Cloud Code Assist, ChatGPT Codex OAuth, Grok, and OpenAI-compatible APIs.
• Markdown/code rendering and expandable tool result cards.
• Startup, runtime, provider, and storage diagnostics.
• Built-in update check with stable, beta, and nightly channels.

Shared app storage

On Android, user-visible Syntac data lives under /storage/emulated/0/.syntac/ when All files access is granted:

.syntac/syntac.sqlite
.syntac/cache/
.syntac/logs/
.syntac/natives/
.syntac/run/
.syntac/agent/SYSTEM.md
.syntac/agent/blobs/
.syntac/agent/config.yml
.syntac/agent/sessions/chats.jsonl
.syntac/agent/sessions/attachments.jsonl

Runtime rootfs, temporary PRoot files, and secrets stay app-private. Existing private and legacy chat stores migrate into this layout without overwriting current files. Global instructions live in .syntac/agent/SYSTEM.md; project .syntac/agent/SYSTEM.md or AGENTS.md overrides it. Grant storage access from Shell Runtime screen when Android reports shared access unavailable.

Android runtime

Syntac can run shell commands through:

1. Packaged Arch Linux PRoot runtime installed into app-private storage.
2. Termux RUN_COMMAND bridge, if Termux is installed and configured.

Termux setup:

mkdir -p ~/.termux
printf 'allow-external-apps=true\n' >> ~/.termux/termux.properties
termux-reload-settings
termux-setup-storage

Then grant Syntac the Termux command permission from Android settings.

Updates

Syntac checks update manifests for the active channel. Current default channel is beta.

Channels:

• stable: tested public releases.
• beta: current default channel.
• nightly: early testing builds.

Current beta APK target:

https://github.com/DraxonV1/Syntac/releases/download/v0.1.1-beta.6/syntac-arm64.apk

Current manifest files:

update/stable.json
update/beta.json
update/nightly.json

GitHub fallback manifest URL:

https://raw.githubusercontent.com/DraxonV1/Syntac/main/update/<channel>.json

Build from source

Requirements:

• Flutter stable with Dart compatible with sdk: ^3.11.5.
• JDK 17.
• Android SDK.
• Android NDK from Flutter/Android tooling.
• Git LFS.

Clone:

git clone https://github.com/DraxonV1/Syntac.git
cd Syntac
git lfs pull

Install dependencies:

flutter pub get

Run checks:

dart format lib test
flutter analyze
flutter test

Build debug/development APK:

flutter build apk --release

Release APK output:

build/app/outputs/flutter-apk/app-release.apk

Releases

com.syntac is public Android package identity. Keep it stable so updates install over existing beta builds.

Contribution and release flow:

• Make source changes on a branch and open PR into master.
• PR CI runs formatting, analysis, and tests without release secrets.
• Review and merge PR only after CI passes.
• Manual Android APK workflow builds signed candidate artifact without creating or moving tags.
• Push exact version tag, such as v0.1.1-beta.6, only after candidate passes physical-phone checks. Tag must match pubspec.yaml.
• Tag workflow rebuilds, verifies, and publishes only matching channel manifest. It never force-moves tags or overwrites other channels, then opens generated manifest-sync PR for master.

Latest beta release:

https://github.com/DraxonV1/Syntac/releases/tag/v0.1.1-beta.6

PR builds never receive release signing credentials or provider OAuth secrets.

Release artifacts:

https://github.com/DraxonV1/Syntac/releases/download/v0.1.1-beta.6/syntac-arm64.apk
update/beta.json

Reference and attribution

Thanks to oh-my-pi for protocol and agent-tool references. Current compatibility audit pins upstream commit e24466515dae616f4027170027245c6222f28ab2 in assets/models/catalog-source.json; upstream source is not vendored.

Runtime sources live under:

• third_party/proot: PRoot
• third_party/termux-proot: Termux PRoot fork

Provider and model icons use the official Lobe Icons unpkg CDN: https://unpkg.com/@lobehub/icons-static-svg@latest/icons/{slug}.svg. Provider and model metadata comes from bundled Models.dev snapshot. Refresh with python scripts/update_model_catalog.py; recorded SHA-256 preserves provenance.

License