Human workloads
A team backs up once a night and serves media to visitors through apps. Objects are large, long-lived, and read by people.
Gigabytes dominate the invoice. Requests are rounding errors.
Storage for AI agents
Agents use object storage as shared working memory: checkpoints, reports, and datasets passed between tools by URL. Frequent writes, repeated reads, and short object lifetimes change which provider costs least.
Two clients, two patterns
The same S3 API serves both, but the access shape barely overlaps. Billing follows the shape, not the technology.
Agent workloads
An agent publishes checkpoints, diffs, reports, and datasets every few minutes. Readers are other agents, model APIs, and pipelines fetching plain URLs.
Operations dominate the invoice. Thousands of small writes per hour and repeated machine reads decide what you pay.
The bill moves to requests
Ranked on a representative agent month: fifty gigabytes kept, one hundred fifty downloaded, five million writes, thirty million reads.
- Writes
- Five million small writes cost $25 on AWS S3 at $5 per million. R2 includes the first million free, then charges $4.50 per million.
- Reads
- Thirty million reads run $12 on AWS at $0.40 per million. R2's ten million free reads plus $0.36 after bring that to $7.20.
- Egress
- R2 never bills downloads; Backblaze B2 and IDrive e2 include three times stored data monthly. S3's free 100 GB disappears fast when models re-fetch artifacts.
- Fine print
- Tiny objects trip minimums: Wasabi retains data at least 90 days, Hetzner bills any object under 64 kB as a full 64 kB, and IDrive floors Pay-Go accounts at one terabyte.
- Lifecycle
- Expiry is the feature. Providers without retention floors let throwaway checkpoints disappear early instead of becoming standing cost.
One month of a coding agent
50 GB stored · 150 GB downloaded · 5M writes · 30M reads
| Provider | Monthly estimate |
|---|---|
| Backblaze B2 | $0.28Lowest |
| Scaleway Multi-AZ | $1.79+$1.51 vs lowest |
| IDrive e2 | $6.00+$5.72 vs lowest |
| AWS S3 Standard | $41.64+$41.37 vs lowest |
AWS S3 Standard is the compatibility baseline most agent frameworks default to. The full model, warnings, and sources are in the main calculator.
Where agents store today
Three options cover most setups. The first two need no infrastructure from you.
- Platform files APIs
Anthropic, OpenAI, and Gemini ship file storage inside their platforms, so agents can attach and share artifacts without any external bucket.
- Dedicated sharing tools
Services like EasySend or f2u expose MCP servers and no-auth upload APIs that turn local files into short-lived links on demand.
- Your own bucket
For production fleets, point agents at S3-compatible storage you control. That is where the pricing rules above decide your bill.