Table of Contents [expand]

• When to Use This Model
• Usage
• Example curl Requests

Last updated May 28, 2026

Claude Opus 4.8 is a large language model (LLM) in Anthropic’s Claude family that supports conversational chat, tool-calling, autonomous coding, effort control, and enhanced reasoning for complex tasks with extended thinking. It offers a highly intelligent, fast, and practical solution you can use to power your AI apps. This version, claude-opus-4-8, offers better performance than the claude-opus-4-7 model.

• Model ID: claude-opus-4-8
• Region: us, eu

When to Use This Model

Claude Opus 4.8 supports a variety of use cases, including advanced software development, complex agentic workflows, and enterprise operations. It’s optimized to combine maximum intelligence and capability with functional performance.

Usage

Claude Opus 4.8 follows our Claude /v1/chat/completions API schema.

To provision access to the model, attach the Managed Inference and Agents add-on to your app $APP_NAME:

heroku addons:create heroku-inference:standard -a $APP_NAME

Using config variables, you can invoke the model in various ways:

• Heroku CLI ai plugin (heroku ai:models:call)
• curl
• Python
• Ruby
• Javascript

Multimodal Support

• Supported inputs: text, image
• Supported outputs: text

Rate Limits

• Maximum requests per minute: 50
• Maximum tokens per minute: 300,000

Prompt Caching

Prompt caching is supported for system prompts and tools. The minimum tokens required for prompt caching is 4,096.

Example curl Requests

To retrieve and export your API credentials:

export INFERENCE_KEY=$(heroku config:get -a $APP_NAME INFERENCE_KEY)
export INFERENCE_URL=$(heroku config:get -a $APP_NAME INFERENCE_URL)

Text to Text

curl $INFERENCE_URL/v1/chat/completions \
  -H "Authorization: Bearer $INFERENCE_KEY" \
  -H "Content-Type: application/json" \
  -d @- <<EOF
{
  "model": "claude-opus-4-8",
  "messages": [
    { "role": "user", "content": "Hello!" },
    { "role": "assistant", "content": "Hi there! How can I assist you today?" },
    { "role": "user", "content": "What's the weather like in Portland, Oregon right now?" }
  ],
  "max_tokens": 100,
  "stream": false,
  "tools": [
    {
      "type": "function",
      "function": {
        "name": "get_weather",
        "description": "Fetches the current weather for a given city.",
        "parameters": {
          "type": "object",
          "properties": {
            "location": {
              "type": "string",
              "description": "The city and state, e.g. San Francisco, CA"
            }
          },
          "required": ["location"]
        }
      }
    }
  ],
  "tool_choice": "auto"
}
EOF

Image to Text

curl -X POST "$INFERENCE_URL/v1/chat/completions" \
  -H "Authorization: Bearer $INFERENCE_KEY" \
  -H "Content-Type: application/json" \
  -d @- <<EOF
{
  "model": "claude-opus-4-8",
  "messages": [
    {
      "role": "user",
      "content": [
        {
          "type": "text",
          "text": "What do you see in this image?"
        },
        {
          "type": "image_url",
          "image_url": {
            "url": "https://upload.wikimedia.org/wikipedia/commons/thumb/e/ec/Heroku_logo.svg/960px-Heroku_logo.svg.png"
          }
        }
      ]
    }
  ]
}
EOF