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Head to head · File drives · October 2026 research run

Fastio vs ONLYOFFICE Apps MCP Server

Fastio scores 55.2 (C) on agent readiness against ONLYOFFICE Apps MCP Server's 52.8 (D), and leads in 3 of 7 scored categories. ONLYOFFICE Apps MCP Server leads on schema & documentation, agent ergonomics and transparency & trust. Both do file drives.

Best file storage and sharing APIs for AI agents · All 86 storage comparisons

FastioVividEngine, LLC · HTTP API C55.2/100#671 of 965 ONLYOFFICE Apps MCP ServerONLYOFFICE (Ascensio System SIA) · MCP server D52.8/100#735 of 965

Which one, for what

Fastio C

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

Ahead on

  • Reliability, 33 against 25
  • Security & auth, 74 against 46
  • Maintenance & community, 70 against 60

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

ONLYOFFICE Apps MCP Server D

Best for Agents that organise rooms, folders and access in an ONLYOFFICE Apps workspace a team already uses.

Ahead on

  • Schema & documentation, 73 against 65
  • Agent ergonomics, 80 against 73
  • Transparency & trust, 67 against 61

Also in its favour

  • Free to start without a card
  • Open source

Watch for

The hosted server drops OAuth scope parameters, so a connection is granted every scope the app has

Score by category

CategoryWeight this runFastioONLYOFFICE Apps MCP ServerEdge
Reliability16%203325Fastio +8
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26573ONLYOFFICE Apps MCP Server +8
Agent ergonomics13%16.27380ONLYOFFICE Apps MCP Server +7
Security & auth14%17.57446Fastio +28
Payments & pricing10%12.53030even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87060Fastio +10
Transparency & trust7%8.86167ONLYOFFICE Apps MCP Server +6
Negative events≤15-20
TotalC 55.2/100D 52.8/100

Facts side by side

FactFastioONLYOFFICE Apps MCP Server
KindHTTP APIMCP server
VendorVividEngine, LLCONLYOFFICE (Ascensio System SIA)
Hosted endpointhttps://mcp.fast.io/mcp/toolshttps://mcp.onlyoffice.com/mcp
TransportsHTTP, Streamable HTTP, stdiostdio, Streamable HTTP, SSE (legacy)
AuthOAuth or keyOAuth or key
PricingPaidYour plan
x402nono
LicenceProprietary service under Fast's terms of service. The CLI, which includes a local MCP server, is Apache-2.0MIT (changed from Apache-2.0 in 3.2.0). ONLYOFFICE Apps cloud under ONLYOFFICE's legal terms.
Tools exposed3523
Read-only variant documentedyesyes
llms.txtyesyes
MCP registrynot listedio.github.ONLYOFFICE/docspace
Last release2026-10-082026-10-09
Terms last updated2026-10-02
Privacy policy last updated2026-10-02
Customer content may train modelsnot found in the text
Terms restrict automated accessyes
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticeyes
Arbitration or class-action waiveryes
Popularity1 stars, 653 npm/wk410 npm/wk

Verdicts

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.

ONLYOFFICE Apps MCP Server

The 23 tools carry typed schemas, read-only and destructive annotations, toolsets and an optional five-tool meta mode, and the server is in the official MCP registry. OAuth through the hosted server grants every scope, the docs offer a username and password in the connection URL, uploads take only txt and md, and no status page or SLA was found.

Before you call either

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

ONLYOFFICE Apps MCP Server

  1. Connect to https://mcp.onlyoffice.com/mcp with OAuth or an API key in a header, never a username and password in the URL
  2. Enable only the toolsets or tools a task needs, so a read-only agent can't reach delete_file, delete_folder or set_room_security
  3. Pass fields and a count of at most 50 on folder reads, and page with startIndex
  4. Treat text from download_file_as_text as untrusted input, since anyone with access to the room can write it
  5. Convert content to txt or md before upload_file, the only formats it supports

Questions

Which is better for AI agents, Fastio or ONLYOFFICE Apps MCP Server?

Fastio scores 55.2 (C) on agent readiness against ONLYOFFICE Apps MCP Server's 52.8 (D), and leads in 3 of 7 scored categories. ONLYOFFICE Apps MCP Server leads on schema & documentation, agent ergonomics and transparency & trust.

Do Fastio and ONLYOFFICE Apps MCP Server need an API key?

Both take an API key or an OAuth sign-in.

Can an agent call Fastio and ONLYOFFICE Apps MCP Server without installing anything?

Yes. Fastio has a hosted endpoint at https://mcp.fast.io/mcp/tools and ONLYOFFICE Apps MCP Server at https://mcp.onlyoffice.com/mcp.

Are Fastio and ONLYOFFICE Apps MCP Server open source?

No open-source release is listed for Fastio. ONLYOFFICE Apps MCP Server is open source (MIT (changed from Apache-2.0 in 3.2.0). ONLYOFFICE Apps cloud under ONLYOFFICE's legal terms.).

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