Custom MT endpoint

A Custom MT endpoint lets you add your own OpenAI-compatible machine-translation service to QuickTrans, alongside the built-in engines (Google, DeepL, Microsoft, …). It is most useful for a local MT proxy – a small server that exposes several free MT engines behind a single OpenAI-compatible API – so you can query them all from Workbench without per-engine API keys.

It is deliberately separate from the AI custom endpoint used for the AI Assistant chat, so you can run an MT proxy for quick lookups and point the AI chat at a different custom LLM at the same time.

When to use it

• You run (or have access to) an OpenAI-compatible endpoint that returns translations, e.g. a local MT proxy that maps a model name to a specific engine (google, sogou, cnpat, …).
• You want fast, free MT in QuickTrans without configuring each engine’s official API key.
• You want more than one such endpoint – for example a general proxy and a patent-specific one – each appearing as its own QuickTrans result.

Set it up

1. Open Workbench Settings → ⚡ QuickTrans.
2. Under MT engines, tick Custom MT endpoint (OpenAI-compatible).
3. Click + next to Profile and give the profile a name (e.g. Local proxy).
4. Fill in:
   • Endpoint URL – the OpenAI-compatible base URL, e.g. http://127.0.0.1:1234/v1
   • Model / engine – the model (or, for a multi-engine proxy, the engine name, e.g. google)
   • API key – only if your endpoint requires one; leave blank otherwise
   • Show this profile in QuickTrans – tick to include this profile as a QuickTrans result; untick to keep it configured but hidden
5. Click 💾 Save QuickTrans Settings.

Each profile that is enabled (Show this profile in QuickTrans ticked) and has an endpoint appears as its own result in the QuickTrans popup (summoned with Ctrl+Alt+Q). Add more profiles with + to expose several engines at once; remove one with −.

Note

The “Custom MT endpoint” checkbox is the master on/off for the whole feature; the per-profile “Show this profile in QuickTrans” checkbox lets you pick which of your saved profiles actually appear, so you can keep several configured but show only the ones you want.

Note

The endpoint must be OpenAI chat-completions compatible (it receives a POST to /v1/chat/completions with messages and a model, and returns the translation as the assistant message). Workbench sends a strict “translate only” prompt, so the endpoint should return just the translated text.

Example: a local multi-engine MT proxy

A common pattern is a small Python proxy that wraps free web MT engines and presents them as OpenAI “models”. Run it locally (e.g. on http://127.0.0.1:1234), then add a Custom MT profile per engine you want, setting Model / engine to the engine name the proxy expects.

Note

Free, unofficial web MT services are best-effort: availability and quality can vary, and they may rate-limit without notice. A proxy keeps that handling outside Workbench. Use each service in line with its own terms, and prefer an official provider API for production work.

Free Dutch ↔ English engines (via a multi-engine proxy)

If your proxy exposes several engines as “models”, set Model / engine to the engine’s key. For Dutch ↔ English, these work well:

Model / engine	Notes
google	Reliable, fast.
microsoft_builtin	Reliable; good Dutch.
modernmt_builtin	Reliable.
lingvanex_builtin	Works; quality varies.
deepl_builtin	Free DeepL — excellent quality when available, but the free endpoint rate-limits aggressively (HTTP 429), so it may intermittently fall back to another engine.

China-focused engines (sogou, transmart, niutrans) and the patent engine cnpat are not recommended for Dutch ↔ English.

Note

These are free, best-effort services and their availability and quality vary; deepl_builtin in particular can be throttled. For dependable, production-grade DeepL, use the official DeepL engine (with an API key) built into Workbench’s MT settings.

Custom MT vs the AI custom endpoint

	Custom MT endpoint	AI custom endpoint
Lives in	QuickTrans ▸ MT engines	AI Settings ▸ AI/LLM Providers
Used for	Fast MT results in QuickTrans	AI Assistant chat & AI translation
Independent?	Yes – configure both at once	Yes
Profiles	Multiple, each a QuickTrans result	Multiple, one active at a time