Skip to main content
~author/family-latest slugs always resolve to the newest concrete model in a given family, so you can ship code against a stable alias and pick up new releases without redeploying.

​
Overview

When a model author ships a new version (for example Anthropic releasing claude-opus-4.8), OpenRouter automatically starts routing ~anthropic/claude-opus-latest to it. Older code calling the alias keeps working — it just runs on the newest version. This is ideal for:
  • Product teams who want to always use the best-in-class model from a specific author without monitoring release notes.
  • Internal tools and prototypes where you care about “latest Claude Opus” more than a specific version pinned for reproducibility.
  • Rolling migrations where you want to defer version pinning until after a release has stabilised.

​
Usage

Send a chat completion request with a ~author/family-latest slug as the model: 
import { OpenRouter } from '@openrouter/sdk';

const openRouter = new OpenRouter({
  apiKey: '<OPENROUTER_API_KEY>',
});

const completion = await openRouter.chat.send({
  model: '~anthropic/claude-opus-latest',
  messages: [
    {
      role: 'user',
      content: 'Summarize this in one sentence: ...',
    },
  ],
});

console.log(completion.choices[0].message.content);
// The `model` field reflects the concrete version that served the request.
console.log('Resolved to:', completion.model);

​
Response

The response’s model field reflects the concrete model that actually served the request, not the alias you sent. This makes it trivial to log or alert on version rollovers: 
{
  "id": "gen-...",
  "model": "anthropic/claude-opus-4.8",
  "choices": [
    {
      "message": {
        "role": "assistant",
        "content": "..."
      }
    }
  ],
  "usage": {
    "prompt_tokens": 12,
    "completion_tokens": 85,
    "total_tokens": 97
  }
}

​
How It Works

Each ~author/family-latest slug is mapped to a model family on OpenRouter. When a request comes in:
  1. Slug recognition: OpenRouter sees the ~ prefix and identifies which family the alias points to (for example ~anthropic/claude-opus-latest → the Claude Opus family).
  2. Target selection: The newest visible model in that family is selected. When a new version ships, it takes over automatically, with no client changes required.
  3. Request forwarding: Your request is forwarded to the resolved model and routed across providers exactly as if you’d called that concrete slug directly.
  4. Transparent reporting: The response’s model field reports the concrete model that served the request (for example anthropic/claude-opus-4.8), so you can always tell which version answered any given call.
If a family has no eligible model available, the request returns an error rather than silently falling back to something unrelated.

​
Pricing and Capabilities

~author/family-latest rows on the models page and in /api/v1/models responses report the pricing, context length, modalities, and supported parameters of the target they currently resolve to — not a frozen snapshot. This way:
  • Clients that list models for their users see accurate per-token prices.
  • Capability-gated flows (for example “only offer this model for vision requests”) see up-to-date modalities.
  • Cost dashboards reflect the real rate charged, because requests are billed at the concrete model’s price.
When a new model is promoted to “latest”, these fields update automatically.

​
Use Cases

  • Always-on assistants: Point user-facing agents at ~anthropic/claude-sonnet-latest and get new releases for free.
  • Evaluation harnesses: Benchmark “the latest” model per author without editing configs.
  • Enterprise pilots: Share a slug with a partner and upgrade them in place when a newer model ships.

​
Limitations

  • Versions can change at any time: When a newer model is rolled in as the latest target, subsequent requests resolve to it. If your application requires a fixed version for reproducibility (for example in regression tests), use the concrete model slug instead.
  • Only latest: The router always resolves to the newest eligible model. There is no built-in way to pin to “second newest” or to roll back through the alias — to downgrade, switch to a concrete slug.
  • Aliases and hidden models are excluded: The router never resolves to another alias slug or to models that have been hidden.

​
Pinning to a Specific Version

When you need reproducibility, bypass latest resolution by calling the concrete model slug directly: 
{
  "model": "anthropic/claude-opus-4.8"
}
You can see the exact slug your last request resolved to in the response’s model field (see above) or in the activity log for the request.