> For the complete documentation index, see [llms.txt](https://docs.coupler.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.coupler.io/destinations/categories/ai/custom_mcp/faq.md).

# FAQ

<details>

<summary>What is MCP?</summary>

MCP (Model Context Protocol) is an open standard for connecting AI models and applications to external data sources and tools. It's designed to be simpler and more standardized than custom APIs.

</details>

<details>

<summary>Can I send data from multiple sources to the same custom MCP?</summary>

Yes. A Coupler.io data flow can contain multiple sources. You can combine data from Google Ads, Shopify, and a database in the same flow, then make it all available via your MCP endpoint. You can also transform the data using Join or Append before it's exposed to clients.

</details>

<details>

<summary>What happens if my MCP client goes down?</summary>

Rest assured – you data is safe with Coupler.io. If your client is unreachable when a scheduled data flow runs, the flow will still succeed, but you will not see the updated data. Once your client is back online, you will be able to get the latest data.

</details>

<details>

<summary>Is there a limit to how much data I can send to Custom MCP?</summary>

Coupler.io has no hard data limits, but your MCP client may have constraints on how much data it can consume. If your data is very large, test with a small sample first.

</details>

<details>

<summary>How do I troubleshoot if data isn't appearing in my MCP client?</summary>

Start by checking:

1. The data flow settings in Coupler.io — look for error messages
2. Your source data — ensure it has rows on the "Data set" wizard step
3. Your MCP client's logs — see if it's connecting successfully
4. Your client's configuration — ensure the personal access token and the URL match what Coupler.io provided

</details>


---

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