What is Vertana?
Vertana[1] is an LLM-powered agentic translation library for TypeScript. It goes beyond a single “prompt in, text out” translation call by orchestrating multiple steps—gathering context, enforcing terminology, evaluating quality, and iteratively refining output.
Vertana is designed for applications where translation is part of a product or a workflow: documentation sites, developer tools, localization pipelines, customer support tooling, or internal knowledge bases.
Why an agentic workflow?
A single-pass translation is often good enough for short, generic text. It becomes fragile when you need:
- Consistent terminology across a document or project
- Domain-aware accuracy in technical, legal, or medical content
- Style consistency (tone, voice, formatting)
- Quality control beyond “sounds okay”
Vertana treats translation as a process. It can gather supporting information, use it during translation, and improve the result until it is acceptable.
How Vertana works
Vertana composes a translation from multiple stages:
- Chunking: Split long input into manageable pieces while preserving formatting and structure.
- Context gathering: Collect relevant information from configured sources (required sources run up front; passive sources are exposed as tools).
- Translation: Generate a draft translation with the available context.
- Evaluation: Score and critique the translation against explicit criteria.
- Refinement: Iteratively apply feedback to improve weak spots.
- Selection: Optionally compare multiple candidates and pick the best.
Not every workflow uses every stage, but the building blocks are there when you need tighter control.
Key concepts
context sources- Pluggable functions that provide additional information. They can inject style guides, background context, glossary databases, or anything else that helps a model make better translation decisions.
glossaries- Term mappings used to enforce consistent translations. Vertana can apply a predefined glossary and can also accumulate terminology as it translates.
refinement- An iterative loop that evaluates quality and improves the translation until it meets configured thresholds.
best-of-N selection- A workflow that generates multiple candidates (potentially from different models) and chooses the most suitable result via comparative evaluation.
Package overview
Vertana is a monorepo with several packages:
- @vertana/facade
- The high-level API. Use this if you want a single
translate()entry point and sensible defaults. - @vertana/core
- The underlying translation pipeline. Use this if you need lower-level building blocks or custom orchestration.
- @vertana/context-web
- Helpers for web-based context gathering. Use this to fetch and extract context from linked pages.
- @vertana/cli
- A command-line interface for translation without writing code.
What Vertana is not
Vertana is intentionally focused on high-quality, product-grade translation. It is not:
- A replacement for full localization platforms (string extraction, translation memory, review workflows, etc.)
- A guarantee of factual correctness (LLMs can still make mistakes)
- A single “magic prompt” that works for every domain without configuration
Next steps
- Start with the Getting started guide.
- Follow the Tutorial for an end-to-end walkthrough.
- Dive deeper in the Manuals section.
The name Vertana is derived from the Sanskrit word वर्तन (vartana), meaning turning, moving, or abiding. ↩︎