if you use aws4fetch, you can get free caching without needing to fiddle with the Cache API manually

const aws_client = new AwsClient({
  accessKeyId: c.env.S3_ACCESS_KEY_ID,
  secretAccessKey: c.env.S3_SECRET_ACCESS_KEY,
  retries: 0,
  service: "s3",
})

const s3_url = new URL(`${c.env.S3_ENDPOINT}/${sha256}.json`);

const s3_result = await aws_client.fetch(s3_url.toString(), {
  method: "GET",
  cf: {
    cacheEverything: true,
    cacheTtl: 31536000, // 1 year
  }
});

const aws_client = new AwsClient({
  accessKeyId: c.env.S3_ACCESS_KEY_ID,
  secretAccessKey: c.env.S3_SECRET_ACCESS_KEY,
  retries: 0,
  service: "s3",
})

const s3_url = new URL(`${c.env.S3_ENDPOINT}/${sha256}.json`);

const s3_result = await aws_client.fetch(s3_url.toString(), {
  method: "GET",
  cf: {
    cacheEverything: true,
    cacheTtl: 31536000, // 1 year
  }
});