List surveys, votes and feedback; create surveys and read Wall of Love items in FeedLetter. Hosted by usefulapi: connect it to Claude, ChatGPT, Cursor or any MCP client.
Turn on the FeedLetter connector, then ask in plain words. The AI picks the tools.
For newsletter writers and publishers who collect votes and feedback with FeedLetter.
Search your surveys by name, id or external id. Then read one survey with its analytics, votes and feedback.
Read the feedback items that one Wall of Love shows, with their answers and dates. Use them to build the wall on your own site.
Create a newsletter survey with an external id, so a repeat call returns the same survey. Use the voting links or email HTML it returns.
Changes dataCreate a web rating widget. Copy the embed HTML it returns to place the widget on your website.
Changes dataThe login page asks for your FeedLetter API key.
Create it in FeedLetter → Account → API Keys. Only the account owner can manage keys. A Read & write key lets the assistant create surveys; a Read key can only list and read them. Your key is used only to call the API on your behalf and to derive a private account id; it is never shown to anyone.
Team and Enterprise: an Owner adds the connector for the organization first.
No Add custom MCP server option? It depends on your account or workspace settings: see OpenAI's guide.
Run this command, then run /mcp in Claude Code to log in:
Add to Cursor or add this to ~/.cursor/mcp.json:
{
"mcpServers": {
"feedletter": {
"url": "https://feedletter.usefulapi.io/mcp"
}
}
} Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"feedletter": {
"type": "http",
"url": "https://feedletter.usefulapi.io/mcp"
}
}
} Run these commands. The second one opens the login page:
Windsurf, Cline, Zed and other MCP clients: add this URL as a remote MCP server (Streamable HTTP). The client then opens the login page in your browser.
Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your FeedLetter API key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
| Plan | Price | Limit |
|---|---|---|
| Free | $0 | 50 tool calls / month |
| Proper user | $9/mo · $90/yr | Unlimited* |
*Pro fair use limit: 10,000 tool calls a month on this server. For more, write to [email protected].
Pro covers this FeedLetter server only. Subscribe with feedletter_upgrade (it returns a Stripe Checkout link). Cancel any time with feedletter_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running feedletter_upgrade before then undoes the cancel. Or write to [email protected].
feedletter_list_surveysfeedletter_get_surveyfeedletter_get_wall_of_lovefeedletter_create_surveyfeedletter_usage_statusfeedletter_request_featurefeedletter_upgradefeedletter_cancel_subscriptionFind a survey and read its votes. Build a Wall of Love into your website. Create a newsletter survey for an issue. Create a web rating widget and get its embed code. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by FeedLetter. The server calls the FeedLetter API with your own FeedLetter access, so it sees only the data that your account can see.
Yes. In Claude, add this server's URL as a custom connector. In ChatGPT, add it as a custom MCP server in Plugins. Then log in once. Cursor, VS Code, Claude Code and Codex work too. See the setup steps.
The login page asks for your FeedLetter API key. See Before you connect for where to find it.
No. Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your FeedLetter API key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
The login stores them encrypted in the authorization grant of your connection. The server uses them to call the FeedLetter API for you and to derive a private account id for usage metering. usefulapi does not show them on any page or in any reply. To stop all access, remove the connector and change or delete these credentials in FeedLetter.
Yes, if you approve it. 1 of the 4 FeedLetter tools can create or change data. The other 3 are marked read-only. Most MCP clients ask you to approve a tool call before it runs.
The Free plan gives 50 tool calls / month. Pro costs $9/mo or $90/yr, with unlimited tool calls (fair use limit: 10,000 tool calls a month), for this FeedLetter server only. Cancel any time: Pro then runs to the end of the paid period. Run feedletter_usage_status to see how many calls you used.
Ask the AI to run feedletter_upgrade: it returns a Stripe Checkout link. To cancel, run feedletter_cancel_subscription. Pro continues to the end of the paid period.
Tell the AI what you wanted to do. It can send the request with feedletter_request_feature. We store the text with the server name, the type of AI client and the tool you tried, not with your account, and read every request when we plan new tools. You can send up to 5 requests per day.
Any client that supports remote MCP servers (Streamable HTTP) with OAuth login: Claude (web and desktop), Claude Code, ChatGPT, Codex, Cursor, VS Code, Windsurf and others.
This is a Model Context Protocol endpoint — meant to be connected from an AI client, not opened in a browser. An invalid_token response at the URL is the auth gate working as designed; clients authenticate automatically.
Need a tool this server does not have, or a connection to another system? We build custom integrations and MCP servers.