Prompt Caching on Bedrock

import Portkey from 'portkey-ai'

const portkey = new Portkey({
    apiKey: "PORTKEY_API_KEY", // defaults to process.env["PORTKEY_API_KEY"]
    virtualKey: "VIRTUAL_KEY" // Your Bedrock Virtual Key
})

const chatCompletion = await portkey.chat.completions.create({
    messages: [
        { "role": 'system', "content": [
            {
                "type":"text","text":"You are a helpful assistant"
            },
            {
                "type":"text","text":"This is a large document I want to cache...",
                "cache_control": {"type": "ephemeral"}
            }
        ]},
        { "role": 'user', "content": 'Summarize the above document for me in 20 words' }
    ],
    model: 'anthropic.claude-3-7-sonnet-20250219-v1:0'
});

console.log(chatCompletion.choices[0].message.content);