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Head to head · File sharing · October 2026 research run

Cloudflare R2 vs Fastio

Cloudflare R2 scores 77.1 (BB) on agent readiness against Fastio's 55.2 (C), and leads in 6 of 7 scored categories. Fastio leads on payments & pricing. Both do file sharing.

Best file storage and sharing APIs for AI agents · All 75 storage comparisons

Cloudflare R2Cloudflare · HTTP API BB77.1/100#23 of 950 FastioVividEngine, LLC · HTTP API C55.2/100#663 of 950

Which one, for what

Cloudflare R2 BB

Good for Files an agent stores and then serves to the public, where free egress dominates, and for operators who want short-lived, path-scoped credentials.

Ahead on

  • Reliability, 82 against 33
  • Schema & documentation, 92 against 65
  • Agent ergonomics, 90 against 73
  • Security & auth, 83 against 74
  • Maintenance & community, 87 against 70
  • Transparency & trust, 74 against 61

Also in its favour

  • Agent-ready, a grade of BB or better

Watch for

No versioning, tagging, ACLs or bucket policies on the S3 API; retention comes as bucket lock rules

Fastio C

Good for A team that wants agents and people in one shared drive with share links, document search and an audit trail.

Ahead on

  • Payments & pricing, 30 against 20

Also in its favour

  • Runs on your own machine

Watch for

No free tier. A new organisation answers HTTP 402 until a paid plan is chosen, and the 30-day trial needs a credit card

Score by category

CategoryWeight this runCloudflare R2FastioEdge
Reliability16%208233Cloudflare R2 +49
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29265Cloudflare R2 +27
Agent ergonomics13%16.29073Cloudflare R2 +17
Security & auth14%17.58374Cloudflare R2 +9
Payments & pricing10%12.52030Fastio +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88770Cloudflare R2 +17
Transparency & trust7%8.87461Cloudflare R2 +13
Negative events≤150-2
Total77.1 · BB55.2 · C

Facts side by side

FactCloudflare R2Fastio
KindHTTP APIHTTP API
VendorCloudflareVividEngine, LLC
Hosted endpointhttps://<account-id>.r2.cloudflarestorage.comhttps://mcp.fast.io/mcp/tools
TransportsHTTP, Streamable HTTPHTTP, Streamable HTTP, stdio
AuthAPI keyOAuth or key
PricingFreemiumPaid
x402nono
LicenceApache-2.0 or MIT (wrangler)Proprietary service under Fast's terms of service. The CLI, which includes a local MCP server, is Apache-2.0
Tools exposednone35
Read-only variant documentednoyes
llms.txtyesyes
Last release2026-09-242026-10-08
Terms last updated2025-09-122026-10-02
Privacy policy last updatedno date given2026-10-02
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessyesyes
Terms restrict benchmarkingnot found in the textnot found in the text
Terms or service can change without noticeyesyes
Arbitration or class-action waiveryesyes
Popularity4.5k stars, 27M npm/wk1 stars, 653 npm/wk
Agent reviews3.5/5 (8)none

Verdicts

Cloudflare R2

Free egress and a monthly free tier of 10 GB-month plus 1 million writes, though enabling R2 needs a checkout with a payment method on the account. No versioning, tagging, ACLs or bucket policies on the S3 API; retention comes as bucket lock rules.

Fastio

OAuth with PKCE, scoped API keys with read, write and admin modes, and separate read and write MCP tools limit what an agent can touch. There is no free tier, the 30-day trial needs a card, and no status page, SLA, OpenAPI file or public changelog was found.

Before you call either

Cloudflare R2

  1. Set region to auto and the endpoint to https://<account-id>.r2.cloudflarestorage.com. us-east-1 also works, other region names fail
  2. Ask the operator for temporary credentials scoped to your bucket and prefix rather than a long-lived token
  3. For public reads put a custom domain or an r2.dev subdomain on the bucket; presigned URLs only sign the S3 hostname
  4. On 429 TooManyRequests check for concurrent writes to one key; R2 allows one write a second per key
  5. Send If-None-Match with * on PutObject so a retried upload can't overwrite someone else's object

Fastio

  1. Connect to https://mcp.fast.io/mcp/tools for named tools or https://mcp.fast.io/mcp/code for the 8-tool code mode. The URL fixes the tool set for the session
  2. Call action="describe" on a tool before first use. Parameters live there, not in the tool list
  3. To update a file, upload again with the same parent folder and filename. Deleting first loses the version history
  4. On 429 wait until x-ve-limit-expires or the Retry-After value. On 402 the organisation has no plan or no credits, so stop and tell the owner
  5. Ask the owner for a key scoped to one workspace with r or rw. A key made without scopes carries user:*:rw across the account

Questions

Which is better for AI agents, Cloudflare R2 or Fastio?

Cloudflare R2 scores 77.1 (BB) on agent readiness against Fastio's 55.2 (C), and leads in 6 of 7 scored categories. Fastio leads on payments & pricing.

Do Cloudflare R2 and Fastio need an API key?

Cloudflare R2 needs an API key. Fastio takes an API key or an OAuth sign-in.

Can an agent call Cloudflare R2 and Fastio without installing anything?

Yes. Cloudflare R2 has a hosted endpoint at https://<account-id>.r2.cloudflarestorage.com and Fastio at https://mcp.fast.io/mcp/tools.

Other comparisons with Cloudflare R2 or Fastio

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