Backblaze B2 Cloud Storage API

Name: Backblaze B2 Cloud Storage API API
Brand: Backblaze B2 Cloud Storage API
Availability: InStock

★ Only Publicly Available OpenAPI DocumentStorageObject Storagebasic24 EndpointsREST

For Agents

Upload, download, and manage objects in Backblaze B2 cloud storage. Create buckets, generate upload URLs, and handle multipart uploads for large files with application key-based access control.

Quickstart

Get started with Backblaze B2 Cloud Storage API in minutes using your preferred integration method.

# Add to your MCP client config (Claude Desktop, Cursor, Windsurf)
{
  "jentic": {
    "url": "https://api.jentic.com/mcp",
    "auth": "oauth"
  }
}

# Then ask your agent:
"upload a file to Backblaze B2 storage"

# → Jentic returns the GET /events tool with parameter schema, agent executes.

Capabilities

What an agent can do with Backblaze B2 Cloud Storage API API.

Upload files to B2 buckets using pre-authorized upload URLs with SHA-1 integrity verification

Download files by ID or by bucket-name-plus-path with byte-range support for partial retrieval

Split files over 100 MB into parts for parallel multipart upload with independent retry per part

Generate scoped application keys that restrict access to specific buckets, path prefixes, or operations

GET STARTED

Start building with Backblaze B2 Cloud Storage API API

Explore with Jentic

View OpenAPI Document

Jentic publishes the only available OpenAPI document for Backblaze B2 Cloud Storage API, keeping it validated and agent-ready.

Jentic publishes the only available OpenAPI specification for Backblaze B2 Cloud Storage API, keeping it validated and agent-ready. Store and retrieve objects in B2 cloud storage with 24 endpoints covering bucket management, file upload and download, application key administration, and large file multipart operations. Pricing runs at one-quarter the cost of major cloud providers with no egress fees for partner integrations and S3-compatible access.

Use Cases

Patterns agents use Backblaze B2 Cloud Storage API API for, with concrete tasks.

★ AI Agent Backup Automation

AI agents automate backup workflows by uploading snapshots, database dumps, and log archives to B2 storage through Jentic. The agent searches for the upload intent, receives the two-step schema (get upload URL, then upload file), and executes without browsing documentation. Application keys scoped to a single bucket ensure agents cannot access unrelated data. At $0.006/GB/month storage, B2 is cost-effective for high-volume backup retention.

Call /b2_get_upload_url for bucket 'daily-backups', then upload a 50 MB database dump using /b2_upload_file with SHA-1 verification

Large File Multipart Upload

Upload files larger than 100 MB using B2's multipart upload mechanism. Start a large file, obtain part upload URLs, upload each part independently (enabling parallel transfers), then finish the upload to assemble the final object. Failed parts can be retried individually without re-uploading the entire file. The API tracks unfinished large files for cleanup.

Start a large file with /b2_start_large_file, get part URLs with /b2_get_upload_part_url, upload 3 parts, then finalize with /b2_finish_large_file

Application Key Access Control

Generate scoped application keys that limit API access to specific buckets, file path prefixes, or operation sets. Distribute keys to different services or agents with least-privilege permissions. Keys can be created with expiration timestamps and restricted to read-only or write-only operations, preventing accidental data deletion from automated systems.

Create a read-only application key scoped to bucket 'public-assets' with prefix 'images/' using /b2_create_key

Cost-Effective Media Asset Storage

Store media files — images, videos, audio — at a fraction of the cost of major cloud providers. B2 charges $0.006/GB/month for storage with free egress through CDN partners (Cloudflare, Fastly). Files are accessed by ID for direct download or by bucket name and file path. Lifecycle rules auto-delete temporary assets after a configured retention period.

List all files with prefix 'videos/' in bucket 'media-assets' using /b2_list_file_names and retrieve metadata for the most recent upload with /b2_get_file_info

Key Endpoints

24 endpoints — jentic publishes the only available openapi specification for backblaze b2 cloud storage api, keeping it validated and agent-ready.

METHOD

PATH

DESCRIPTION

POST

/b2_authorize_account

Authenticate and receive API URL and auth token

POST

/b2_get_upload_url

Get a URL for uploading files to a bucket

POST

/b2_upload_file

Upload a file to the bucket using the authorized URL

POST

/b2_download_file_by_id

Download a file by its unique file ID

POST

/b2_list_file_names

List file names in a bucket with optional prefix filter

POST

/b2_create_bucket

Create a new storage bucket

POST

/b2_create_key

Create a new application key with scoped permissions

POST

/b2_start_large_file

Begin a multipart upload for a large file

POST

/b2_authorize_account

Authenticate and receive API URL and auth token

POST

/b2_get_upload_url

Get a URL for uploading files to a bucket

POST

/b2_upload_file

Upload a file to the bucket using the authorized URL

POST

/b2_download_file_by_id

Download a file by its unique file ID

POST

/b2_list_file_names

List file names in a bucket with optional prefix filter

Why though Jentic?

Three things that make agents converge on Jentic-routed access.

Credential isolation

Backblaze B2 application key IDs and secrets are stored encrypted in the Jentic vault (MAXsystem). Agents receive pre-authorized tokens — raw keys never enter the agent's context.

Intent-based discovery

Agents search by intent (e.g., 'upload a file to cloud storage') and Jentic returns matching B2 operations with their input schemas, including the two-step upload flow (get URL then upload).

Time to first call

Direct B2 integration: 1-2 days for auth flow, upload URL management, and multipart handling. Through Jentic: under 1 hour — search, load schema, execute.

Related APIs

Alternatives and complements available in the Jentic catalogue.

Alternative

Google Cloud Storage

Multi-tier object storage with tight GCP integration and global redundancy options

Choose Google Cloud Storage when you need multi-region replication, object lifecycle tiering (Nearline/Coldline/Archive), or native GCP service integration

Complementary

Cloudflare API

CDN, DNS, and edge computing platform for content delivery

Use alongside B2 to serve stored objects through Cloudflare's CDN with zero egress fees via the Bandwidth Alliance partnership

Complementary

Cloudinary Admin API

Media asset management with on-the-fly image and video transformations

Use alongside B2 when stored media needs real-time transformations (resize, crop, format conversion) before delivery to end users

FAQs

Specific to using Backblaze B2 Cloud Storage API API through Jentic.

Why is there no official OpenAPI spec for Backblaze B2 Cloud Storage API?

Backblaze does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call Backblaze B2 Cloud Storage API via structured tooling. It is validated against the live API and kept up to date. Get started at https://app.jentic.com/sign-up.

What authentication does the Backblaze B2 API use?

The B2 API uses HTTP Basic authentication for the initial /b2_authorize_account call, where the username is the application key ID and the password is the application key. This returns an authorization token and API URL used for all subsequent requests. Through Jentic, these credentials are stored encrypted in the MAXsystem vault.

Can I upload files larger than 100 MB with the B2 API?

Yes. Files under 100 MB use the single-call /b2_upload_file endpoint. Larger files use the multipart flow: /b2_start_large_file to initiate, /b2_get_upload_part_url for each part URL, upload parts individually (minimum 5 MB each except the last), then /b2_finish_large_file to assemble. Maximum file size is 10 TB.

How do I list files in a B2 bucket through Jentic?

Search Jentic for 'list files in a Backblaze bucket' to load the /b2_list_file_names operation schema. Pass the bucketId and optional prefix/delimiter parameters to filter results. The endpoint returns up to 10,000 files per call with a nextFileName cursor for pagination. Install with pip install jentic.

What are the rate limits for the Backblaze B2 API?

B2 allows unlimited API calls for most read operations. Write operations are limited to approximately 100 calls per second per account. The /b2_authorize_account endpoint is limited to prevent brute-force attacks. The API returns HTTP 429 or 503 with a Retry-After header when limits are hit.

How does B2 pricing compare to other cloud storage providers?

B2 storage costs $0.006/GB/month — roughly one-quarter the price of AWS S3 Standard. Download bandwidth is $0.01/GB, and egress through CDN partners (Cloudflare, Fastly, Bunny) is free. There are no minimum storage durations or per-request charges for standard operations.