List Models

beta.models.list(**kwargs) -> Page<BetaModelInfo { id, capabilities, created_at, 4 more } >

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.

ParametersExpand Collapse

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.

Accepts one of the following:

String

:"message-batches-2024-09-24" | :"prompt-caching-2024-07-31" | :"computer-use-2024-10-22" | 19 more

Accepts 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"

ReturnsExpand Collapse

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

id: String

Unique model identifier.

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

Model capability information.

batch: BetaCapabilitySupport { supported }

Whether the model supports the Batch API.

supported: bool

Whether this capability is supported by the model.

citations: BetaCapabilitySupport { supported }

Whether the model supports citation generation.

supported: bool

Whether this capability is supported by the model.

code_execution: BetaCapabilitySupport { supported }

Whether the model supports code execution tools.

supported: bool

Whether this capability is supported by the model.

context_management: BetaContextManagementCapability { clear_thinking_20251015, clear_tool_uses_20250919, compact_20260112, supported }

Context management support and available strategies.

clear_thinking_20251015: BetaCapabilitySupport { supported }

Indicates whether a capability is supported.

supported: bool

Whether this capability is supported by the model.

clear_tool_uses_20250919: BetaCapabilitySupport { supported }

Indicates whether a capability is supported.

supported: bool

Whether this capability is supported by the model.

compact_20260112: BetaCapabilitySupport { supported }

Indicates whether a capability is supported.

supported: bool

Whether this capability is supported by the model.

supported: bool

Whether this capability is supported by the model.

effort: BetaEffortCapability { high, low, max, 2 more }

Effort (reasoning_effort) support and available levels.

high: BetaCapabilitySupport { supported }

Whether the model supports high effort level.

supported: bool

Whether this capability is supported by the model.

low: BetaCapabilitySupport { supported }

Whether the model supports low effort level.

supported: bool

Whether this capability is supported by the model.

max: BetaCapabilitySupport { supported }

Whether the model supports max effort level.

supported: bool

Whether this capability is supported by the model.

medium: BetaCapabilitySupport { supported }

Whether the model supports medium effort level.

supported: bool

Whether this capability is supported by the model.

supported: bool

Whether this capability is supported by the model.

image_input: BetaCapabilitySupport { supported }

Whether the model accepts image content blocks.

supported: bool

Whether this capability is supported by the model.

pdf_input: BetaCapabilitySupport { supported }

Whether the model accepts PDF content blocks.

supported: bool

Whether this capability is supported by the model.

structured_outputs: BetaCapabilitySupport { supported }

Whether the model supports structured output / JSON mode / strict tool schemas.

supported: bool

Whether this capability is supported by the model.

thinking: BetaThinkingCapability { supported, types }

Thinking capability and supported type configurations.

supported: bool

Whether this capability is supported by the model.

types: BetaThinkingTypes { adaptive, enabled }

Supported thinking type configurations.

adaptive: BetaCapabilitySupport { supported }

Whether the model supports thinking with type 'adaptive' (auto).

supported: bool

Whether this capability is supported by the model.

enabled: BetaCapabilitySupport { supported }

Whether the model supports thinking with type 'enabled'.

supported: bool

Whether this capability is supported by the model.

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.

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.beta.models.list

puts(page)

Response 200

{
  "data": [
    {
      "id": "claude-opus-4-6",
      "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
        },
        "image_input": {
          "supported": true
        },
        "pdf_input": {
          "supported": true
        },
        "structured_outputs": {
          "supported": true
        },
        "thinking": {
          "supported": true,
          "types": {
            "adaptive": {
              "supported": true
            },
            "enabled": {
              "supported": true
            }
          }
        }
      },
      "created_at": "2026-02-04T00:00:00Z",
      "display_name": "Claude Opus 4.6",
      "max_input_tokens": 0,
      "max_tokens": 0,
      "type": "model"
    }
  ],
  "first_id": "first_id",
  "has_more": true,
  "last_id": "last_id"
}

Returns Examples

Response 200

{
  "data": [
    {
      "id": "claude-opus-4-6",
      "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
        },
        "image_input": {
          "supported": true
        },
        "pdf_input": {
          "supported": true
        },
        "structured_outputs": {
          "supported": true
        },
        "thinking": {
          "supported": true,
          "types": {
            "adaptive": {
              "supported": true
            },
            "enabled": {
              "supported": true
            }
          }
        }
      },
      "created_at": "2026-02-04T00:00:00Z",
      "display_name": "Claude Opus 4.6",
      "max_input_tokens": 0,
      "max_tokens": 0,
      "type": "model"
    }
  ],
  "first_id": "first_id",
  "has_more": true,
  "last_id": "last_id"
}