Claude Sonnet 4.5 (2025-09-29) API

Model details

Context window

200K tokens

Max output

64K tokens

Input

Text, images

Output

Text

Capabilities

Reasoning, Vision, Tool calling, Streaming

Interfaces

OpenAI-style Chat Completions, Anthropic-style Messages, OpenAI-style Responses

Why teams pick it

• Claude Sonnet 4.5 (2025-09-29) for OpenAI-style Chat Completions, Anthropic-style Messages, OpenAI-style Responses.

Call Claude Sonnet 4.5 (2025-09-29)

Claude Sonnet 4.5 (2025-09-29) answers on any of the APIs below — pick the one your code already speaks and just swap in your Inferray key.

curl https://api.inferray.com/v1/chat/completions \
  -H "Authorization: Bearer inferray_..." \
  -H "Content-Type: application/json" \
  -d '{
  "model": "claude-sonnet-4-5-20250929",
  "messages": [
    {
      "role": "user",
      "content": "Hello"
    }
  ]
}'

curl https://api.inferray.com/v1/messages \
  -H "Authorization: Bearer inferray_..." \
  -H "Content-Type: application/json" \
  -d '{
  "model": "claude-sonnet-4-5-20250929",
  "max_tokens": 1024,
  "messages": [
    {
      "role": "user",
      "content": "Hello"
    }
  ]
}'

curl https://api.inferray.com/v1/responses \
  -H "Authorization: Bearer inferray_..." \
  -H "Content-Type: application/json" \
  -d '{
  "model": "claude-sonnet-4-5-20250929",
  "input": "Hello"
}'

Use Claude Sonnet 4.5 (2025-09-29) in your tools

Every coding agent below has a setup guide. Set the model to claude-sonnet-4-5-20250929.

• Claude Code
• Codex
• opencode
• Cline
• Roo Code
• Aider
• Continue

More from Anthropic

Alternatives to Claude Sonnet 4.5 (2025-09-29)

• Kimi K3Long-horizon coding and end-to-end knowledge work.Moonshot AI
• Grok 4Grok 4 for OpenAI-style Chat Completions, Anthropic-style Messages, OpenAI-style Responses.xAI
• Mistral Large LatestMistral Large Latest for OpenAI-style Chat Completions, Anthropic-style Messages, OpenAI-style Responses.Mistral

Questions about this model

How much does the Claude Sonnet 4.5 (2025-09-29) API cost?

Claude Sonnet 4.5 (2025-09-29) costs $3 per 1M input tokens and $15 per 1M output tokens on Inferray, and cached input is $0.3 per 1M. That is the list price, with no gateway fee on top.

Is there a free tier for Claude Sonnet 4.5 (2025-09-29)?

No. You add credit and pay Claude Sonnet 4.5 (2025-09-29)'s list rate for each request — seats, projects, and API keys are free, and pay-as-you-go credit never expires.

Am I charged for failed requests?

No. A request that fails without returning a result is not billed. If a response fails part-way, the tokens already processed before the failure are charged.

Is Claude Sonnet 4.5 (2025-09-29) included in Token Plans?

No. Claude Sonnet 4.5 (2025-09-29) is pay-as-you-go only; Token Plans cover the other text models in the catalog.

Can I use Claude Sonnet 4.5 (2025-09-29) in Claude Code?

Yes. Set ANTHROPIC_BASE_URL to https://api.inferray.com, ANTHROPIC_AUTH_TOKEN to your Inferray key, and ANTHROPIC_MODEL to claude-sonnet-4-5-20250929. The same key works in Codex, opencode, Cline, and other agents.

Does Claude Sonnet 4.5 (2025-09-29) support tool calling and vision?

Claude Sonnet 4.5 (2025-09-29) supports tool calling, image input, reasoning and streaming on Inferray.

Is it the real Claude Sonnet 4.5 (2025-09-29)?

Yes. A request for claude-sonnet-4-5-20250929 is answered by Claude Sonnet 4.5 (2025-09-29) from Anthropic, billed at its published list price. Inferray never substitutes a different or smaller model.