Authenticate against R2 API using auth tokens

The following example shows how to authenticate against R2 using the S3 API and an API token.

Note

For providing secure access to bucket objects for anonymous users, we recommend using pre-signed URLs instead.

Pre-signed URLs do not require users to be a member of your organization and enable programmatic application directly.

Ensure you have set the following environmental variables prior to running either example:

export R2_ACCOUNT_ID=your_account_id
export R2_ACCESS_KEY_ID=your_access_key_id
export R2_SECRET_ACCESS_KEY=your_secret_access_key
export R2_BUCKET_NAME=your_bucket_name

JavaScript

Install the aws-sdk package for the S3 API:

npm install aws-sdk

const AWS = require('aws-sdk');
const crypto = require('crypto');

const ACCOUNT_ID = process.env.R2_ACCOUNT_ID;
const ACCESS_KEY_ID = process.env.R2_ACCESS_KEY_ID;
const SECRET_ACCESS_KEY = process.env.R2_SECRET_ACCESS_KEY;
const BUCKET_NAME = process.env.R2_BUCKET_NAME;

// Hash the secret access key
const hashedSecretKey = crypto.createHash('sha256').update(SECRET_ACCESS_KEY).digest('hex');

// Configure the S3 client for Cloudflare R2
const s3Client = new AWS.S3({
    endpoint: `https://${ACCOUNT_ID}.r2.cloudflarestorage.com`,
    accessKeyId: ACCESS_KEY_ID,
    secretAccessKey: hashedSecretKey,
    signatureVersion: 'v4',
    region: 'auto' // Cloudflare R2 doesn't use regions, but this is required by the SDK
});

// Specify the object key
const objectKey = '2024/08/02/ingested_0001.parquet';

// Function to fetch the object
async function fetchObject() {
    try {
        const params = {
            Bucket: BUCKET_NAME,
            Key: objectKey
        };

        const data = await s3Client.getObject(params).promise();
        console.log('Successfully fetched the object');

        // Process the data as needed
        // For example, to get the content as a Buffer:
        // const content = data.Body;

        // Or to save the file (requires 'fs' module):
        // const fs = require('fs').promises;
        // await fs.writeFile('ingested_0001.parquet', data.Body);

    } catch (error) {
        console.error('Failed to fetch the object:', error);
    }
}

fetchObject();

Python

Install the boto3 S3 API client:

pip install boto3

Run the following Python script with python3 get_r2_object.py. Ensure you change object_key to point to an existing file in your R2 bucket.

get_r2_object.py

import os
import hashlib
import boto3
from botocore.client import Config

ACCOUNT_ID = os.environ.get('R2_ACCOUNT_ID')
ACCESS_KEY_ID = os.environ.get('R2_ACCESS_KEY_ID')
SECRET_ACCESS_KEY = os.environ.get('R2_SECRET_ACCESS_KEY')
BUCKET_NAME = os.environ.get('R2_BUCKET_NAME')

# Hash the secret access key using SHA-256
hashed_secret_key = hashlib.sha256(SECRET_ACCESS_KEY.encode()).hexdigest()

# Configure the S3 client for Cloudflare R2
s3_client = boto3.client('s3',
    endpoint_url=f'https://{ACCOUNT_ID}.r2.cloudflarestorage.com',
    aws_access_key_id=ACCESS_KEY_ID,
    aws_secret_access_key=hashed_secret_key,
    config=Config(signature_version='s3v4')
)

# Specify the object key
object_key = '2024/08/02/ingested_0001.parquet'

try:
    # Fetch the object
    response = s3_client.get_object(Bucket=BUCKET_NAME, Key=object_key)

    print('Successfully fetched the object')

    # Process the response content as needed
    # For example, to read the content:
    # object_content = response['Body'].read()

    # Or to save the file:
    # with open('ingested_0001.parquet', 'wb') as f:
    #     f.write(response['Body'].read())

except Exception as e:
    print(f'Failed to fetch the object. Error: {str(e)}')

Go

Use go get to add the aws-sdk-go-v2 packages to your Go project:

go get github.com/aws/aws-sdk-go-v2
go get github.com/aws/aws-sdk-go-v2/config
go get github.com/aws/aws-sdk-go-v2/credentials
go get github.com/aws/aws-sdk-go-v2/service/s3

Run the following Go application as a script with go run main.go. Ensure you change objectKey to point to an existing file in your R2 bucket.

package main

import (
    "context"
    "crypto/sha256"
    "encoding/hex"
    "fmt"
    "io"
    "log"
    "os"

    "github.com/aws/aws-sdk-go-v2/aws"
    "github.com/aws/aws-sdk-go-v2/config"
    "github.com/aws/aws-sdk-go-v2/credentials"
    "github.com/aws/aws-sdk-go-v2/service/s3"
)

func main() {
    // Load environment variables
    accountID := os.Getenv("R2_ACCOUNT_ID")
    accessKeyID := os.Getenv("R2_ACCESS_KEY_ID")
    secretAccessKey := os.Getenv("R2_SECRET_ACCESS_KEY")
    bucketName := os.Getenv("R2_BUCKET_NAME")

    // Hash the secret access key
    hasher := sha256.New()
    hasher.Write([]byte(secretAccessKey))
    hashedSecretKey := hex.EncodeToString(hasher.Sum(nil))

    // Configure the S3 client for Cloudflare R2
    r2Resolver := aws.EndpointResolverWithOptionsFunc(func(service, region string, options ...interface{}) (aws.Endpoint, error) {
        return aws.Endpoint{
            URL: fmt.Sprintf("https://%s.r2.cloudflarestorage.com", accountID),
        }, nil
    })

    cfg, err := config.LoadDefaultConfig(context.TODO(),
        config.WithEndpointResolverWithOptions(r2Resolver),
        config.WithCredentialsProvider(credentials.NewStaticCredentialsProvider(accessKeyID, hashedSecretKey, "")),
        config.WithRegion("auto"), // Cloudflare R2 doesn't use regions, but this is required by the SDK
    )
    if err != nil {
        log.Fatalf("Unable to load SDK config, %v", err)
    }

    // Create an S3 client
    client := s3.NewFromConfig(cfg)

    // Specify the object key
    objectKey := "2024/08/02/ingested_0001.parquet"

    // Fetch the object
    output, err := client.GetObject(context.TODO(), &s3.GetObjectInput{
        Bucket: aws.String(bucketName),
        Key:    aws.String(objectKey),
    })
    if err != nil {
        log.Fatalf("Unable to fetch object, %v", err)
    }
    defer output.Body.Close()

    fmt.Println("Successfully fetched the object")

    // Process the object content as needed
    // For example, to save the file:
    // file, err := os.Create("ingested_0001.parquet")
    // if err != nil {
    //   log.Fatalf("Unable to create file, %v", err)
    // }
    // defer file.Close()
    // _, err = io.Copy(file, output.Body)
    // if err != nil {
    //   log.Fatalf("Unable to write file, %v", err)
    // }

    // Or to read the content:
    content, err := io.ReadAll(output.Body)
    if err != nil {
        log.Fatalf("Unable to read object content, %v", err)
    }
    fmt.Printf("Object content length: %d bytes\n", len(content))
}