Baltor Get started

Models

Claude Sonnet 4.5

By Anthropic. Unknown parameters, a context window of 1,000,000 tokens, licence Unknown.

Facts

Released
2025-09-29 the release date models.dev records models.dev, read
Licence
Unknown
Open weights
No models.dev records whether the weights are open models.dev, read
Parameters
Unknown
Active parameters
Unknown
Knowledge cutoff
2025-07-31 the knowledge cutoff models.dev records models.dev, read
Context window
  • 1,000,000 tokens the context limit models.dev records for the maker's own API models.dev, read
Longest output
  • 64,000 tokens the output limit models.dev records for the maker's own API models.dev, read
Tool calling
  • Yes models.dev records tool_call as true models.dev, read
Structured output
  • Yes models.dev records structured_output as true models.dev, read
Reasoning controls
  • Yes models.dev records reasoning as true models.dev, read
Inputs and outputs
text, image, pdf in, text out models.dev, read
Good for
  • Vision: models.dev lists images among its inputs models.dev, read
  • Reasoning: models.dev records it as a reasoning model models.dev, read

Prices

Prices in US dollars per million tokens, as each source lists them
ProviderInputOutputContextAs ofSource
Anthropic direct3.00 USD15.00 USD1,000,000 older than 30 days; check the providermodels.dev, read

Run it on your own hardware

No source lists weight files or a parameter count for this model, so its memory needs are Unknown.

Use it from your harness

Set up for Anthropic with the model claude-sonnet-4-5-20250929. Each endpoint page has the same setup for its own address.

OpenCode

Put this in opencode.json in your project folder:

{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "anthropic": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "Anthropic",
      "options": {
        "baseURL": "https://api.anthropic.com/v1",
        "apiKey": "{env:ANTHROPIC_API_KEY}"
      },
      "models": {
        "claude-sonnet-4-5-20250929": {
          "name": "Claude Sonnet 4.5",
          "limit": {
            "context": 1000000,
            "output": 64000
          }
        }
      }
    }
  }
}
  • OpenCode reads any OpenAI-compatible address through the @ai-sdk/openai-compatible package, and an address that speaks the Responses API through @ai-sdk/openai.

From OpenCode documentation, read .

Pi

Put this in ~/.pi/agent/models.json:

{
  "providers": {
    "anthropic": {
      "baseUrl": "https://api.anthropic.com/v1",
      "api": "openai-completions",
      "apiKey": "$ANTHROPIC_API_KEY",
      "models": [
        {
          "id": "claude-sonnet-4-5-20250929"
        }
      ]
    }
  }
}
  • The apiKey field can name an environment variable as $NAME.

From Pi documentation, read .

Codex

Codex speaks only the Responses API, and Anthropic documents no Responses address. A gateway that offers one can sit in between.

  • Codex speaks the Responses API only: responses is the one supported wire API of a custom provider. Ollama and LM Studio are built in and start with --oss.

From Codex documentation, read .

Claude Code

Put this in ~/.claude/settings.json, or variables in your shell:

claude --model claude-sonnet-4-5-20250929

From Claude Code documentation, read .

Sources of this page