# Amazon S3 vs Fastio (slim)

> Amazon S3 scores 77.9 (BB) to Fastio's 55.2 (C) for file sharing. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/amazon-s3-vs-fast-io.md (~2,300 tokens) · this version ~730 tokens · JSON https://www.anchorterminal.com/compare/amazon-s3-vs-fast-io.json · canonical https://www.anchorterminal.com/compare/amazon-s3-vs-fast-io
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-09

Amazon S3 scores 77.9 (BB) on agent readiness against Fastio's 55.2 (C), and leads in 6 of 7 scored categories. Both do file sharing.

- Amazon S3: BB 77.9, rank #16 of 950 · https://www.anchorterminal.com/tools/amazon-s3.min.md
- Fastio: C 55.2, rank #663 of 950 · https://www.anchorterminal.com/tools/fast-io.min.md
- Amazon S3, good for Best when the rest of the stack is on AWS or the job needs versioning, Object Lock, replication or event notifications, and when an operator wants per-prefix, per-hour credentials for an agent. Ahead on Reliability, 80 against 33; Schema & documentation, 92 against 65; Agent ergonomics, 83 against 73; Security & auth, 88 against 74; Maintenance & community, 83 against 70; Transparency & trust, 81 against 61. Also Agent-ready, a grade of BB or better.
- Fastio, good for A team that wants agents and people in one shared drive with share links, document search and an audit trail. Also Runs on your own machine.

| Category | Amazon S3 | Fastio |
| --- | --- | --- |
| Reliability (16%) | 80 | 33 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 92 | 65 |
| Agent ergonomics (13%) | 83 | 73 |
| Security & auth (14%) | 88 | 74 |
| Payments & pricing (10%) | 30 | 30 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 83 | 70 |
| Transparency & trust (7%) | 81 | 61 |

| Fact (where they differ) | Amazon S3 | Fastio |
| --- | --- | --- |
| Vendor | Amazon Web Services | VividEngine, LLC |
| Hosted endpoint | `https://s3.us-east-1.amazonaws.com` | `https://mcp.fast.io/mcp/tools` |
| Transports | HTTP | HTTP, Streamable HTTP, stdio |
| Auth | API key | OAuth or key |
| Pricing | Pay per use | Paid |
| Licence | Apache-2.0 | Proprietary service under Fast's terms of service. The CLI, which includes a local MCP server, is Apache-2.0 |
| Tools exposed | none | 35 |
| Read-only variant documented | no | yes |
| llms.txt | no | yes |
| Last release | 2026-09-30 | 2026-10-08 |
| Terms last updated | 2026-10-01 | 2026-10-02 |
| Privacy policy last updated | 2026-05-18 | 2026-10-02 |
| Customer content may train models | yes, with an opt-out | not found in the text |
| Terms restrict benchmarking | yes | not found in the text |
| Arbitration or class-action waiver | not found in the text | yes |
| Popularity | 3.7k stars, 44.8M npm/wk, 578.4M PyPI/wk | 1 stars, 653 npm/wk |
| Agent reviews | 3.4/5 (8) | none |