OpenRouter LLM provider for Strapi Translate Plugin

Translate your Strapi content using any LLM via OpenRouter or any OpenAI-compatible API (OpenAI, Ollama, LM Studio, etc.).

This provider is part of strapi-plugin-translate-llm.

Installation

npm install strapi-plugin-translate-llm strapi-provider-translate-openrouter

Configuration

Configure the provider through the plugin options in config/plugins.js:

module.exports = ({ env }) => ({
  // ...
  translate: {
    enabled: true,
    config: {
      provider: 'openrouter',
      providerOptions: {
        // Your API key - required (or set OPENROUTER_API_KEY env var)
        apiKey: env('OPENROUTER_API_KEY'),
        // Model to use (default: 'anthropic/claude-sonnet-4')
        model: 'anthropic/claude-sonnet-4',
        // Temperature: 0.1-0.3 = literal, 0.5-0.7 = creative (default: 0.3)
        temperature: 0.3,
        // Custom instructions appended to the translation prompt
        customPrompt: 'Keep "MyBrand" untranslated. Use informal register.',
        // Map Strapi locale codes to human-readable language names
        localeMap: {
          en: 'English',
          fr: 'French',
          sv: 'Swedish',
        },
        // Use a different OpenAI-compatible API (default: 'https://openrouter.ai/api/v1')
        // apiUrl: 'https://api.openai.com/v1',
      },
      translatedFieldTypes: [
        'string',
        { type: 'text', format: 'plain' },
        { type: 'richtext', format: 'html' },
        'component',
        'dynamiczone',
      ],
    },
  },
  // ...
})

Or use the default environment variables:

• OPENROUTER_API_KEY - required, your OpenRouter API key
• OPENROUTER_API_URL - optional, override the API endpoint

To get an API key, register at openrouter.ai/keys.

Provider Options

| Option | Type | Default | Description | |--------|------|---------|-------------| | apiKey | string | OPENROUTER_API_KEY env var | Required. API key | | model | string | anthropic/claude-sonnet-4 | Any OpenRouter model | | temperature | number | 0.3 | Controls translation creativity | | customPrompt | string | — | Additional translation instructions | | localeMap | object | {} | Maps locale codes to language names | | maxTextsPerRequest | number | 20 | Max texts batched per LLM call | | maxConcurrent | number | 3 | Max parallel API requests | | apiUrl | string | https://openrouter.ai/api/v1 | API endpoint URL |

Recommended Models

| Model | Best for | Approximate cost | |-------|----------|-----------------| | anthropic/claude-sonnet-4 | Best quality/cost balance | ~$3/1M tokens | | anthropic/claude-haiku-4-5 | Fast, cheap, simple content | ~$0.80/1M tokens | | google/gemini-2.5-flash | Very cheap, fast | ~$0.15/1M tokens | | openai/gpt-4o | Strong alternative | ~$2.50/1M tokens | | openai/gpt-4o-mini | Budget option | ~$0.15/1M tokens |

Using Other OpenAI-Compatible APIs

The provider uses the OpenAI SDK internally, so it works with any compatible endpoint:

// OpenAI directly
providerOptions: {
  apiKey: env('OPENAI_API_KEY'),
  apiUrl: 'https://api.openai.com/v1',
  model: 'gpt-4o',
}

// Local Ollama
providerOptions: {
  apiKey: 'ollama',
  apiUrl: 'http://localhost:11434/v1',
  model: 'llama3',
}

Custom Prompt

The customPrompt option appends additional instructions to the system prompt. The base prompt already handles format preservation (HTML tags, Markdown syntax, JSON structure), so focus on domain-specific rules:

// Preserve brand names
customPrompt: 'Keep "UCPA" and "MyBrand" untranslated.'

// Control tone
customPrompt: 'Use informal "du" in Swedish, not "ni".'

// Combine rules
customPrompt: `
  Keep "UCPA" untranslated.
  Use informal register in all languages.
  Translate ski terminology naturally for the target audience.
`

Reliability

• Retry with backoff — transient errors (429, 500, 502, 503) are retried up to 2 times with exponential backoff
• Rate limiting — Bottleneck-based concurrency control prevents overwhelming the API
• Batch fallback — if the LLM returns a malformed batch response, texts are automatically re-sent one at a time
• HTTP keep-alive — the plugin writes periodic heartbeat bytes during slow translations, preventing reverse proxy timeouts (Heroku 30s, AWS ALB 60s)

Supported Formats

| Format | How it works | |--------|-------------| | plain | Direct text translation | | markdown | LLM preserves all Markdown syntax | | html | LLM preserves HTML tags and attributes, translates only text content | | jsonb (Blocks) | Converted to HTML before translation, converted back after |

Limitations

• LLM translation costs vary by model and text volume — monitor usage via the admin UI or your OpenRouter dashboard
• Translation quality depends on the chosen model; larger models produce better results for nuanced content
• Very long texts may be split into chunks, which can occasionally affect cross-paragraph context