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.
Autonomous clients
Storage for AI agents
When the client is an autonomous agent, object storage stops being a bucket behind your app and becomes shared working memory. Agents drop artifacts in, other agents and models pull them out by URL, and most objects live for hours instead of years. That changes what you pay for.
What it is
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.
Why costs shift
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 each. 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.
Worked example
One day of a coding agent
Monthly estimate at published rates
50 GB stored · 150 GB downloaded · 5M writes · 30M reads
| B2Backblaze B2 | $0.28Lowest |
|---|---|
| SCScaleway Multi-AZ | $1.79+$1.51 vs lowest |
| e2IDrive e2 | $6.00+$5.72 vs lowest |
| S3AWS S3 Standard | $42.65+$42.37 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.
Landscape
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.