Frequently Asked Questions

Quick answers to the questions that come up most often when evaluating or starting with Syntax.

Is Syntax open source?

Syntax is a proprietary product — your Fully Managed, Privately Owned, General-Purpose AI Factory, built on dUX. The Syntax platform itself is free of additional charge; you pay only for the infrastructure it runs on, via dUX.

What platforms are supported?

macOS 12+, Linux (Ubuntu 20.04+ / Debian 11+ / Fedora 38+ / equivalent glibc-based distros), and Windows 10 (21H2)+ / Windows 11. x86_64 and ARM64 are both supported. See Getting Started → Install.

Do I need a GPU?

No. Syntax runs without a GPU; smaller models serve on CPU and larger requests can route to hosted providers. With a GPU (NVIDIA, AMD ROCm, or Apple Silicon) you can run larger models locally.

Which coding assistants does Syntax support?

The Syntax CLI, Codex, Claude Code, OpenCode, and Pi. You can use multiple at once; they share the same active model policy. See Harnesses → Overview.

Does Syntax send my code to a server?

Only if you choose to. Syntax runs on infrastructure you own — your machine for local serving, your boxes for self-managed remote, your dUX-managed environment for managed remote. Your sessions stay within your boundary unless you've configured a hosted provider. The control plane never sees your session content.

How does Syntax make money?

The Syntax platform itself is free of additional charge. You pay for the infrastructure it runs on, via dUX.

Can I use my own provider keys?

Yes. OpenAI, Anthropic, Google, and other supported providers all work with your own API keys. Syntax routes requests through the Bridge so the keys are stored within your environment and never leave your control.

How does Syntax compare to running an OpenAI-compatible proxy myself?

A custom proxy gets you the routing primitive. Syntax adds:

Hardware-aware multi-engine inference for local serving.
Multi-model party deployments.
Managed remote inference (with dUX).
Per-harness connect/disconnect so you don't manually edit each tool's config.
Plan Mode, Agent Handoff, Runtime Modes.
Budgets, exposed-endpoint bearers, audit.

If a custom proxy gets you 70% of what you need, Syntax gets you 100% without you maintaining it.

Yes. Issue a per-deployment exposed-endpoint bearer (sk-syntax-…) from the desktop app. The bearer is scoped to a single deployment and can be revoked at any time. The exposed URL is OpenAI- and Anthropic-compatible so any tool that speaks either ecosystem can use it.

Does Syntax work offline?

Local inference works offline by definition. Hosted-provider routing needs network. Managed remote needs network to dUX. The desktop app itself runs offline.

Can Syntax run on on-prem, air-gapped infrastructure?

Absolutely. Syntax fully supports on-prem and air-gapped deployments. You run a dUX server on your internal network, and it orchestrates whatever compute Syntax needs from the hardware you've made available behind your perimeter. You then choose which OSS models to import into the internal catalog, and from there the internal dUX server manages your private model and image registries — so every user on your private network gets the full Syntax experience without ever leaving the walled garden.

How does Plan Mode differ from "just asking the agent to plan first"?

Plan Mode separates the planning context from the execution context. The executor starts fresh and works from the approved plan, not from the back-and-forth that produced it. That's structurally different from "please plan first then execute" in the same conversation. See Concepts → Plan Mode.