List Models

models.list(**kwargs) -> Page<ModelInfo>

GET/v1/models

List available models.

The Models API response can be used to determine which models are available for use in the API. More recently released models are listed first.

Parameters

after_id: String

ID of the object to use as a cursor for pagination. When provided, returns the page of results immediately after this object.

before_id: String

ID of the object to use as a cursor for pagination. When provided, returns the page of results immediately before this object.

limit: Integer

Number of items to return per page.

Defaults to 20. Ranges from 1 to 1000.

maximum1000

minimum1

betas: Array[AnthropicBeta]

Optional header to specify the beta version(s) you want to use.

One of the following:

String = String

AnthropicBeta = :"message-batches-2024-09-24" | :"prompt-caching-2024-07-31" | :"computer-use-2024-10-22" | 38 more

One of the following:

:"message-batches-2024-09-24"

:"prompt-caching-2024-07-31"

:"computer-use-2024-10-22"

:"computer-use-2025-01-24"

:"pdfs-2024-09-25"

:"token-counting-2024-11-01"

:"token-efficient-tools-2025-02-19"

:"output-128k-2025-02-19"

:"files-api-2025-04-14"

:"mcp-client-2025-04-04"

:"mcp-client-2025-11-20"

:"dev-full-thinking-2025-05-14"

:"interleaved-thinking-2025-05-14"

:"code-execution-2025-05-22"

:"extended-cache-ttl-2025-04-11"

:"context-1m-2025-08-07"

:"context-management-2025-06-27"

:"model-context-window-exceeded-2025-08-26"

:"skills-2025-10-02"

:"fast-mode-2026-02-01"

:"output-300k-2026-03-24"

:"user-profiles-2026-03-24"

:"user-profiles-2026-08-18"

:"advisor-tool-2026-03-01"

:"managed-agents-2026-04-01"

:"cache-diagnosis-2026-04-07"

:"dreaming-2026-04-21"

:"thinking-token-count-2026-05-13"

:"server-side-fallback-2026-06-01"

:"server-side-fallback-2026-07-01"

:"fallback-credit-2026-06-01"

:"fallback-credit-2026-07-01"

:"agent-memory-2026-07-22"

:"mid-conversation-tool-changes-2026-07-01"

:"compact-2026-01-12"

:"computer-use-2025-11-24"

:"mcp-tunnels-2026-06-22"

:"structured-outputs-2025-11-13"

:"task-budgets-2026-03-13"

:"thinking-display-updates-2026-08-18"

:"ce-user-management-2026-07-13"

Returns

class ModelInfo { id, capabilities, created_at, 4 more }

id: String

Unique model identifier.

capabilities: ModelCapabilities { batch, citations, code_execution, 6 more }

Model capability information.

created_at: Time

RFC 3339 datetime string representing the time at which the model was released. May be set to an epoch value if the release date is unknown.

formatdate-time

display_name: String

A human-readable name for the model.

max_input_tokens: Integer

Maximum input context window size in tokens for this model.

max_tokens: Integer

Maximum value for the max_tokens parameter when using this model.

type: :model

Object type.

For Models, this is always "model".

List Models

require "anthropic"

anthropic = Anthropic::Client.new(api_key: "my-anthropic-api-key")

page = anthropic.models.list

puts(page)

{
  "data": [
    {
      "id": "claude-opus-5",
      "capabilities": {
        "batch": {
          "supported": true
        },
        "citations": {
          "supported": true
        },
        "code_execution": {
          "supported": true
        },
        "context_management": {
          "clear_thinking_20251015": {
            "supported": true
          },
          "clear_tool_uses_20250919": {
            "supported": true
          },
          "compact_20260112": {
            "supported": true
          },
          "supported": true
        },
        "effort": {
          "high": {
            "supported": true
          },
          "low": {
            "supported": true
          },
          "max": {
            "supported": true
          },
          "medium": {
            "supported": true
          },
          "supported": true,
          "xhigh": {
            "supported": true
          }
        },
        "image_input": {
          "supported": true
        },
        "pdf_input": {
          "supported": true
        },
        "structured_outputs": {
          "supported": true
        },
        "thinking": {
          "supported": true,
          "types": {
            "adaptive": {
              "supported": true
            },
            "enabled": {
              "supported": true
            }
          }
        }
      },
      "created_at": "2026-07-24T00:00:00Z",
      "display_name": "Claude Opus 5",
      "max_input_tokens": 0,
      "max_tokens": 0,
      "type": "model"
    }
  ],
  "first_id": "first_id",
  "has_more": true,
  "last_id": "last_id"
}

Returns Examples

{
  "data": [
    {
      "id": "claude-opus-5",
      "capabilities": {
        "batch": {
          "supported": true
        },
        "citations": {
          "supported": true
        },
        "code_execution": {
          "supported": true
        },
        "context_management": {
          "clear_thinking_20251015": {
            "supported": true
          },
          "clear_tool_uses_20250919": {
            "supported": true
          },
          "compact_20260112": {
            "supported": true
          },
          "supported": true
        },
        "effort": {
          "high": {
            "supported": true
          },
          "low": {
            "supported": true
          },
          "max": {
            "supported": true
          },
          "medium": {
            "supported": true
          },
          "supported": true,
          "xhigh": {
            "supported": true
          }
        },
        "image_input": {
          "supported": true
        },
        "pdf_input": {
          "supported": true
        },
        "structured_outputs": {
          "supported": true
        },
        "thinking": {
          "supported": true,
          "types": {
            "adaptive": {
              "supported": true
            },
            "enabled": {
              "supported": true
            }
          }
        }
      },
      "created_at": "2026-07-24T00:00:00Z",
      "display_name": "Claude Opus 5",
      "max_input_tokens": 0,
      "max_tokens": 0,
      "type": "model"
    }
  ],
  "first_id": "first_id",
  "has_more": true,
  "last_id": "last_id"
}