Messagevisor lets teams manage application copy, translations, and locale behavior as source code:

1. Manage a Messagevisor project in Git.
2. Author messages, locales, targets, overrides, segments, tests, and examples as YAML or JSON.
3. Validate everything with the CLI.
4. Build compact target and locale-specific datafiles.
5. Serve those JSON datafiles from a CDN or application server.
6. Evaluate translations, formatting, and conditional copy with the SDK.

• Translations as code: review copy changes in pull requests with the same workflow as application code.
• Targeted datafiles: ship only the messages, locales, formats, metadata, and override logic each app needs.
• Runtime conditions: define attributes, segments, and ordered overrides for plan, platform, country, feature flag, experiment, and audience-specific copy.
• Locale inheritance: share translations and format presets across language and regional variants.
• Portable formatting: define named number, date, time, relative, and range presets that SDKs can consume consistently.
• Review UI: generate the Catalog to inspect messages, locales, targets, examples, relationships, Git history, and optional reports.
• Release lanes: use sets and promotion flows for dev, staging, production, or parallel localization streams.

npx messagevisor init
npm install

npx messagevisor lint
npx messagevisor build
npx messagevisor catalog

Read the full Quick start when you are ready to wire a generated datafile into an application.

Run commands inside a Messagevisor project:

npx messagevisor <command> [options]

See the CLI docs for all options. The fastest correctness loop while authoring is usually:

npx messagevisor lint
npx messagevisor evaluate --message=<key> --locale=<locale> --target=<target>
npx messagevisor test --keyPattern=<key>
npx messagevisor diff
npx messagevisor diff --resolved

diff compares HEAD with a dirty working tree, or main/master with the current branch when clean. Use --from and --to for explicit refs and --format=markdown for a PR-friendly report. It reports authored copy, workflow, and override routing changes; add --resolved to include downstream locale-inheritance impact.

Catalog is a generated, read-only website for reviewing a Messagevisor project:

npx messagevisor catalog
npx messagevisor catalog export
npx messagevisor catalog serve
npx messagevisor catalog --set=staging --set=production

Translation-value search and duplicate reports are opt-in because they can be expensive in large projects:

npx messagevisor catalog --with-translation-search
npx messagevisor catalog --with-duplicates
npx messagevisor catalog export --with-translation-search --with-duplicates

catalog serve requires and serves already generated output. Run catalog export first. It does not build optional search or duplicate indexes.

For sets-based projects, catalog generation includes all sets by default. Pass --set=<name> one or more times to generate only selected sets.

This monorepo includes focused projects under projects/:

Try one:

npx @messagevisor/cli init --project=environments
npm install

npx messagevisor info
npx messagevisor test
npx messagevisor catalog

Applications consume built datafiles, not source YAML or JSON files:

import { createMessagevisor } from "@messagevisor/sdk";
import { createIcuModule } from "@messagevisor/module-icu";
import datafile from "./datafiles/messagevisor-web-en-US.json";

const m = createMessagevisor({
  datafile,
  modules: [createIcuModule()],
});

m.translate("auth.signin");
m.translate("dashboard.welcome", { name: "Ada" });

See the SDK docs for JavaScript, React, Vue, browser, Node.js, React Native, and react-intl compatibility usage.

Messagevisor ships an agent skill in skills/messagevisor. It helps AI coding agents understand the project model, choose safe commands, author translations, run evaluate, write tests, use Catalog, and avoid editing generated output as source.

Install it with:

npx skills add messagevisor/messagevisor

See skills/README.md for details.

Install dependencies at the monorepo root:

npm install

Useful checks:

npm run typecheck
npm run test
npm run build

Targeted package checks:

npm run test --workspace @messagevisor/core
npm run test --workspace @messagevisor/catalog
npm run build --workspace @messagevisor/catalog

Read the Contributing docs for project conventions and release workflow.

MIT © Fahad Heylaal