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Head to head · App automation · October 2026 research run

StackOne vs Unified.to MCP Server

StackOne scores 69.1 (B) on agent readiness against Unified.to MCP Server's 61.9 (C), and leads in 5 of 7 scored categories. Both do app automation.

Best agent tool access platforms · All 28 tool access comparisons

StackOneStackOne Technologies Limited · MCP server B69.1/100#198 of 950 Unified.to MCP ServerUnified API Inc. · MCP server C61.9/100#455 of 950

Which one, for what

StackOne B

Good for A company that wants one governed MCP endpoint for staff agents across business systems, and product teams embedding per-customer connections with HR, recruiting and CRM coverage.

Ahead on

  • Reliability, 80 against 73
  • Security & auth, 69 against 50
  • Payments & pricing, 38 against 30

Also in its favour

  • Free to start without a card

Watch for

Session token URLs (https://api.stackone.com/mcp?token=...) put the credential in the query string, cover one linked account and expire after one year by default

Unified.to MCP Server C

Good for A B2B software team that already uses or plans to use Unified's API and wants the same customer connections exposed to an LLM, with data read live from the source app.

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

The default credential is a workspace API key. The docs say it grants access to all connections and the whole Unified.to account

Score by category

CategoryWeight this runStackOneUnified.to MCP ServerEdge
Reliability16%208073StackOne +7
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27881Unified.to MCP Server +3
Agent ergonomics13%16.27571StackOne +4
Security & auth14%17.56950StackOne +19
Payments & pricing10%12.53830StackOne +8
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88484even
Transparency & trust7%8.86966StackOne +3
Negative events≤15-2-3
Total69.1 · B61.9 · C

Facts side by side

FactStackOneUnified.to MCP Server
KindMCP serverMCP server
VendorStackOne Technologies LimitedUnified API Inc.
Hosted endpointhttps://mcp.stackone.com/mcphttps://mcp-api.unified.to/mcp
TransportsStreamable HTTP, HTTPStreamable HTTP
AuthOAuth or keyOAuth or key
PricingFreemiumPaid
x402nono
LicenceProprietary service under StackOne's SaaS Terms and Conditions. The Agent SDKs (@stackone/ai, stackone-ai) and the Defender package (@stackone/defender) are Apache-2.0Proprietary service under Unified.to's Terms of Service. The linked repository is sample client code
Read-only variant documentednono
llms.txtyesyes
MCP registrycom.stackone/mcpto.unified/core
Last release2026-09-242026-10-08
Terms last updated2026-03-30no date given
Privacy policy last updated2023-12-012026-10-02
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessnot found in the textnot found in the text
Terms restrict benchmarkingnot found in the textyes
Terms or service can change without noticenot found in the textnot found in the text
Arbitration or class-action waivernot found in the textnot found in the text
Popularity30 stars, 277 npm/wk22k npm/wk

Verdicts

StackOne

StackOne's MCP server signs each person in with OAuth, lets them grant individual accounts and actions, and by default exposes two search and execute tools in place of the full catalogue. Session token URLs carry the credential in the query string for a year by default, and the Consumption Schedule and pricing page disagree on whether failed calls are billed.

Unified.to MCP Server

Every previewed tool carries a typed input schema and read-only, destructive and idempotent annotations, and the list can be narrowed by permission or tool name. The default credential is a workspace API key that reaches every connection, and the SSE transport was removed on 23 September 2026 in the changelog entry that announced it.

Before you call either

StackOne

  1. Send Accept: application/json,text/event-stream on every MCP request to https://api.stackone.com/mcp, by POST only. Without it the server answers 406
  2. In search_execute mode call {provider}_search_actions first and pass the returned action_id to {provider}_execute_action. Never hardcode action ids
  3. Pass the API key as the Basic auth username with an empty password, and name the linked account in x-account-id
  4. On 429 or 408 wait the seconds given in Retry-After. StackOne has already retried a provider's 429 up to five times within a 60-second request lifetime
  5. On 412 read errorCode and details.statusReasons. AccountErrorStatus needs a person to re-authenticate the linked account

Unified.to MCP Server

  1. Use the host for the workspace's region. US is mcp-api.unified.to, EU is mcp-api-eu.unified.to and AU is api-au.unified.to. A credential on another region's host resolves to not found
  2. Send the key as Authorization: Bearer <key> and put connection=<id> in the URL. Without connection the server lists workspace management tools, not the customer's data tools
  3. Pass tools or permissions in the URL before listing. An unfiltered connection can list dozens of tools with large output schemas
  4. Expect HTTP 429 on tool calls since 23 September 2026. Unified does not queue or retry, so back off and retry yourself
  5. Page with limit (100 at most on most endpoints) and offset, and stop when a page returns fewer records than limit

Questions

Which is better for AI agents, StackOne or Unified.to MCP Server?

StackOne scores 69.1 (B) on agent readiness against Unified.to MCP Server's 61.9 (C), and leads in 5 of 7 scored categories.

Do StackOne and Unified.to MCP Server need an API key?

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

Can an agent call StackOne and Unified.to MCP Server without installing anything?

Yes. StackOne has a hosted endpoint at https://mcp.stackone.com/mcp and Unified.to MCP Server at https://mcp-api.unified.to/mcp.

Other comparisons with StackOne or Unified.to MCP Server

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