Install & quickstart

glot is a single Rust binary: a CLI, an MCP server for coding agents and, optionally, an API + dashboard. It works with the i18n library you already use (next-intl, i18next/react-i18next, FormatJS) and keeps your catalogs as plain JSON in Git.

Install

Pick one channel. They all install the same prebuilt binary from the GitHub release, checked against its SHA-256.

Check it: glot --version.

Coding agents get it through their own channels: the Claude Code plugin (claude plugin marketplace add MattJeff/glot), the MCP registry entry io.github.MattJeff/glot, or any MCP client with npx -y glot-i18n mcp. See Integrations.

1. glot init

Run it at the root of your app:

glot init                       # interactive
glot init --yes --targets fr,de,ja --provider anthropic

It detects your stack and catalogs, then writes:

• glot.toml: source and target locales, catalog paths, format, message syntax, LLM settings;
• glossary.toml: your product terms (empty to start);
• agent rules: CLAUDE.md, AGENTS.md, .claude/skills/glot, .cursor/rules/glot.mdc, .mcp.json;
• a GitHub workflow (.github/workflows/glot.yml) that checks and translates on pull requests.

A minimal glot.toml:

source_locale = "en"
target_locales = ["fr", "de", "ja"]
files = ["messages/{locale}.json"]
format = "auto"          # auto | json-nested | json-flat
syntax = "icu"           # icu | i18next | mf2

[llm]
provider = "anthropic"   # anthropic | openai | openai-compatible | mock
model = "claude-haiku-5-5"
fallback_model = "claude-sonnet-5-5"
api_key_env = "ANTHROPIC_API_KEY"
budget_usd = 5.0

2. glot i18nize (apps with hardcoded strings)

If your UI text is still hardcoded, glot i18nize rewrites it to translation calls:

glot extract                    # list hardcoded strings, missing and unused keys
glot i18nize --dry-run          # show the diff and the keys it would create
glot i18nize --yes              # rewrite the code, fill the source catalog, wire the library

It handles JSX text with expressions and inline tags, attributes, concatenations and template literals, and turns count-based concatenations into ICU plurals. Key names come from one LLM call; the rewrite itself is deterministic. It also wires the runtime it detects (next-intl provider, config and proxy; react-i18next init; see Frameworks). Pass --no-setup to only rewrite code, --switcher to also get a <LocaleSwitcher />.

On the bundled demo app (examples/demo-saas, a small Next.js invoicing SaaS), extract finds 117 hardcoded strings. After i18nize, extract reports nothing left. A few strings are deliberately skipped and listed with the reason (for example sample data in module-level arrays).

3. glot translate

Try it without a key

The mock provider needs no API key and no network: it writes placeholder translations (⟦fr⟧ …) through the same pipeline (plan, validator, lockfile, catalogs), so you can see what glot does before paying for anything.

glot init --yes --targets fr,de --provider mock
glot translate --yes
glot status

Switch to a real provider later by editing [llm] in glot.toml, then run glot translate --force to replace the placeholders.

With an LLM key

export ANTHROPIC_API_KEY=...
glot translate --dry-run        # plan + estimated cost, writes nothing
glot translate                  # translates missing and stale strings only
glot translate --batch          # same, through the Message Batches API: -50 %, asynchronous, resumable
glot check                      # deterministic QA, exit 1 on errors (--format text|json|sarif|github)

Every output goes through the validator before it is written. Hand-edited translations are never overwritten without --force. glot status shows coverage per locale and what the next translate would do.

Visual commands need Node.js and Chromium

glot fit, glot measure, glot coverage --render and glot translate --visual drive a real browser through the @glot-i18n/visual-qa helper (Playwright); glot parity uses @glot-i18n/agent-qa. The glot binary itself needs neither. glot starts the helper with npx -y @glot-i18n/visual-qa (pinned to its own version) unless glot-visual-qa is on your PATH, so you only need:

node --version                   # Node.js >= 20
npx -y playwright install chromium

To use a local checkout instead, set GLOT_VISUAL_QA=/path/to/visual-qa/dist/cli.js (GLOT_AGENT_QA for parity).

Next steps

• Let your coding agent do this while you code: MCP server.
• Keep it running on every pull request: GitHub Action.
• Fix translations that overflow their button: pixel budgets and glot fit.
• Edit text in the running app with Alt+click: glot dev + overlay.