B2 Cloud Storage Management

Manage Backblaze B2 cloud storage: list files, audit usage, estimate cost, clean up stale data, and review security posture.

Security Rules (MANDATORY)

1. Never run b2 account get, b2 account clear, or any b2 key * subcommand — these expose or mutate credentials.
2. Never read ~/.b2_account_info or any file matching *b2_account_info* — this is the B2 credential database (SQLite).
3. Always run b2 rm --dry-run before any real deletion; show the user what would be deleted and require an explicit "yes" before executing.
4. Never change a bucket to allPublic without first warning the user about the security implications and getting explicit confirmation.
5. Default to read-only — only perform writes or deletes when the user explicitly requests them.
6. Never store or write API keys, application keys, or account IDs to any file.
7. If the user pastes key values into the chat instead of the terminal, warn them immediately and recommend rotating the key. Never echo, store, or reference key values that appear in conversation.

First-Use Flow

1. Check the B2 CLI is installed: b2 version. If missing, ask the user to install the CLI outside the agent, then rerun b2 version - see references/setup.md for detail.
2. Verify the CLI is authorized: b2 ls. If it fails with an auth error, walk the user through references/setup.md.
3. Check for a per-project config at .claude/b2-config.json in the project root. If missing, ask the user for bucket + prefix and create one.