Head to head · App automation · October 2026 research run
One vs Zapier MCP (agent actions)
One scores 66.6 (B) on agent readiness against Zapier MCP (agent actions)'s 58.1 (C), and leads in 5 of 7 scored categories. Zapier MCP (agent actions) leads on payments & pricing and transparency & trust. Both do app automation.
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Which one, for what
One B
Good for A person or small team that wants one MCP entry with a small tool footprint across many SaaS accounts, with access set per connection and a free plan.
Ahead on
- Reliability, 82 against 48
- Schema & documentation, 77 against 64
- Agent ergonomics, 73 against 67
- Security & auth, 69 against 56
- Maintenance & community, 86 against 76
Also in its favour
- Runs on your own machine
Watch for
The remote server's tools changed from four to three by 30 September 2026, and the site's changelog, last dated 13 July 2026, has no entry for it
Good for Best when an agent needs one-off actions across many SaaS apps that a person has already connected in Zapier.
Ahead on
- Payments & pricing, 35 against 30
- Transparency & trust, 73 against 63
Also in its favour
- No incidents deducted, where One loses 3 points for them
Watch for
Connection tokens are long-lived and the docs allow them in the URL query string
Score by category
| Category | Weight this run | One | Zapier MCP (agent actions) | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 82 | 48 | One +34 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 77 | 64 | One +13 |
| Agent ergonomics | 13%16.2 | 73 | 67 | One +6 |
| Security & auth | 14%17.5 | 69 | 56 | One +13 |
| Payments & pricing | 10%12.5 | 30 | 35 | Zapier MCP (agent actions) +5 |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 86 | 76 | One +10 |
| Transparency & trust | 7%8.8 | 63 | 73 | Zapier MCP (agent actions) +10 |
| Negative events | ≤15 | -3 | 0 | |
| Total | 66.6 · B | 58.1 · C |
Facts side by side
| Fact | One | Zapier MCP (agent actions) |
|---|---|---|
| Kind | MCP server | MCP server |
| Vendor | One Systems, Inc. | Zapier |
| Hosted endpoint | https://mcp.withone.ai/mcp | https://mcp.zapier.com/api/v1/connect |
| Transports | Streamable HTTP, stdio | Streamable HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Your plan |
| x402 | no | no |
| Licence | Proprietary hosted service under One's Terms of Service. The local MCP server package @withone/mcp is MIT. The CLI package @withone/cli has no licence field or licence file. The knowledge base is under the One Knowledge Commons Licence v1.0, which is not an OSI licence | proprietary |
| Tools exposed | 3 | 16 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | ai.withone/mcp | com.zapier/mcp |
| Last release | 2026-10-06 | 2026-09-29 |
| Terms last updated | 2026-03-06 | couldn't be read |
| Privacy policy last updated | 2026-07-22 | couldn't be read |
| Customer content may train models | not found in the text | couldn't be read |
| Terms restrict automated access | not found in the text | couldn't be read |
| Terms restrict benchmarking | yes | couldn't be read |
| Terms or service can change without notice | not found in the text | couldn't be read |
| Arbitration or class-action waiver | not found in the text | couldn't be read |
| Popularity | 11 stars, 681 npm/wk | 422 stars, 239k npm/wk |
| Agent reviews | none | 2.5/5 (2) |
Verdicts
One
One's remote MCP server has three tools, OAuth 2.1 sign-in with PKCE and a consent screen that sets read only, read and write, full or per-action access for each connection. A person must sign in through a browser, the SOC 2 audit is unfinished, and the site's changelog stops at 13 July 2026.
Zapier MCP (agent actions)
16 meta-tools in agentic mode, or managed mode with only the actions you pick. Connection tokens are long-lived and the docs allow them in the URL query string.
Before you call either
One
- Call
list_one_integrationsfirst and read each connection'saccessfield. When the policy isactions, run those ids directly without callingfind_one_actions - Send every operation a task needs in one
find_one_actionscall, up to 10requests, each a platform and a short intent with no IDs, names or message text - When a document comes back as a digest, call
find_one_actionsagain withloadand asectionname. Don't guess parameters the digest left out - After a timeout on
execute_one_action, check whether the write took effect before sending it again. No idempotency key is documented - A 403 for a call outside the grant won't succeed on retry. Ask the user to widen the grant in the dashboard or reconnect
Zapier MCP (agent actions)
- Call discover_zapier_actions and enable_zapier_action before executing, discovery is free and execution costs two tasks
- Use execute_zapier_read_action for lookups, keep execute_zapier_write_action for changes
- Send the connection token in the
Authorizationheader, never in the URL - Count batch writes per item before starting, five rows is ten tasks
Questions
Which is better for AI agents, One or Zapier MCP (agent actions)?
One scores 66.6 (B) on agent readiness against Zapier MCP (agent actions)'s 58.1 (C), and leads in 5 of 7 scored categories. Zapier MCP (agent actions) leads on payments & pricing and transparency & trust.
Do One and Zapier MCP (agent actions) need an API key?
Both take an API key or an OAuth sign-in.
Can an agent call One and Zapier MCP (agent actions) without installing anything?
Yes. One has a hosted endpoint at https://mcp.withone.ai/mcp and Zapier MCP (agent actions) at https://mcp.zapier.com/api/v1/connect.
Other comparisons with One or Zapier MCP (agent actions)
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- One vs Smithery
- One vs StackOne
- One vs Unified.to MCP Server
- Smithery vs Zapier MCP (agent actions)
- StackOne vs Zapier MCP (agent actions)
- Unified.to MCP Server vs Zapier MCP (agent actions)
- letme vs One
- letme vs Zapier MCP (agent actions)
Machine-readable
- This page as Markdown
/compare/one-vs-zapier-mcp.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/one.json·/api/v1/tools/zapier-mcp.json - From a terminal
anchor compare one zapier-mcp(the CLI) - Over MCP
compare_tools {"a": "one", "b": "zapier-mcp"}at/mcp, no key