# We've added a line field to the Models API

By Steven Van · 2026-10-01

Developers can group models in a model picker without parsing IDs, with Claude Opus 4.5 and 4.6 both reporting opus.

Developers can now group models from [Anthropic](<https://creatorstoolbox.com/tools/anthropic>) without parsing their IDs. GET /v1/models and GET /v1/models/{model\_id} return a line field naming the model line each model belongs to.

## Grouping models by line

Claude Opus 4.5 and Claude Opus 4.6 both return opus, for example, allowing applications to group them together in a model picker. The field is null when a model belongs to no line.

The [Models API documentation](<https://platform.claude.com/docs/en/models/overview#using-the-models-api>) advises reading line instead of inferring it from the model's id. Anthropic may add more lines, so applications should not treat the possible values as a fixed set.

![Anthropic](<https://www.google.com/s2/favicons?domain=anthropic.com&sz=128>)

Anthropic

Anthropic is an AI safety and research company that's working to build reliable, interpretable, and steerable AI systems.

[View Anthropic →](<https://creatorstoolbox.com/tools/anthropic>)

[Original source](<https://platform.claude.com/docs/en/release-notes/overview#october-1-2026>)

[Read We've added a line field to the Models API on Creators Toolbox](<https://creatorstoolbox.com/blog/anthropic-we-ve-added-a-line-field-to-the-models-api>)

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Canonical source: https://creatorstoolbox.com/blog/anthropic-we-ve-added-a-line-field-to-the-models-api