Where does the Cursor MCP config go?

Use .cursor/mcp.json for one project or ~/.cursor/mcp.json for every project. Both use the same format.

Why would I use a Reddit MCP inside Cursor?

To check what real users report about a library, bug or tool while you code, with links to the threads.

Is the API key safe in mcp.json?

Treat it like any secret. Keep it in the global file or out of version control, and revoke it from Settings if it leaks.

Does Cursor ask before calling the tools?

By default Cursor asks you to approve MCP tool calls. You can change that in its settings.

Cursor setup

Add the Reddinbox MCP server to Cursor

Cursor supports remote MCP servers with a url and headers in mcp.json. Add Reddinbox once and the agent can look up what real users say about a bug, a library or a competitor while you code.

Get your API key I already have an account

Free trial. No credit card required.

.cursor/mcp.json

{
  "mcpServers": {
    "reddinbox": {
      "url": "https://reddinbox.com/api/mcp",
      "headers": {
        "Authorization": "Bearer rdb_your_api_key"
      }
    }
  }
}

Endpoint: https://reddinbox.com/api/mcp. Swap the placeholder for your key.

Steps

Set up Cursor step by step

1
Create an API key
Sign up, open Settings, then API keys. Create a key and copy it. It starts with rdb_ and is shown once.
2
Create or edit mcp.json
Add the reddinbox block below. If the file exists, add it next to your other servers.
3
Enable the server
Open Cursor Settings, then MCP. Switch Reddinbox on and wait for the green status dot.
4
Use it in the agent
Ask the Cursor agent to search a topic. Approve the tool call when Cursor asks.

Where the config lives

Per project: .cursor/mcp.json in the project root.
Global: ~/.cursor/mcp.json, available in every project.
You can also add it from Cursor Settings, MCP.

Check it works

First prompts to try

Search Reddit for developers complaining about this library and summarize the top issues.
Look up Hacker News discussions about this framework's latest release.
Get this thread's comments and list the workarounds people suggest.

Tools

What Cursor can call

search_threads

Search Reddit, X, Hacker News, Bluesky and Facebook. Spam and AI-generated noise is filtered out. Returns raw posts with links.

querystringrequired: What to search for.
platformsstring[]: Limit to specific platforms. Defaults to all your plan allows.
communitystring: Subreddit or community to search within.
timestring: Time range, e.g. day, week, month, year.
limitnumber: Max posts to return.

Example response

{
  "posts": [
    {
      "platform": "reddit",
      "title": "The new export flow is much slower after the update",
      "body": "Since the last release, exporting takes over a minute...",
      "url": "https://www.reddit.com/r/example/comments/abc123/",
      "author": "example_user",
      "community": "r/example",
      "engagement": {
        "upvotes": 214,
        "comments": 58
      },
      "created_at": "2026-09-30T14:12:00Z"
    }
  ]
}

get_thread

Fetch a full Reddit or Hacker News thread with its nested comment tree.

urlstringrequired: Thread URL.
max_commentsnumber: Max comments to return (default 300, max 500).

Example response

{
  "post": {
    "title": "The new export flow is much slower",
    "url": "https://www.reddit.com/r/example/comments/abc123/"
  },
  "comments": [
    {
      "author": "another_user",
      "body": "Same here, started right after the update.",
      "score": 41,
      "replies": []
    }
  ]
}

summarize_feedback
Summarize sentiment and themes from a query or from posts you already fetched.
querystring
Search and summarize. Provide this or posts.
postsobject[]
Posts from search_threads to summarize.
focusstring
What to focus on, e.g. a feature name.
Example response
```
{
  "summary": "Mostly negative on export speed; positive on the new dashboard.",
  "themes": [
    {
      "label": "Slow exports",
      "sentiment": "negative",
      "sources": [
        "https://www.reddit.com/r/example/comments/abc123/"
      ]
    }
  ]
}
```

list_briefs

List your Reddinbox Market Briefs and the latest report for each.

No parameters.

Example response

{
  "briefs": [
    {
      "id": "uuid",
      "niche_label": "Project management software",
      "platforms": [
        "reddit",
        "x"
      ]
    }
  ]
}

run_research
Run a full Reddinbox research strategy on a topic: keyword and community selection, multi-platform search, filtering.
topicstringrequired
Topic to research.
Example response
```
{
  "strategy": {
    "keywords": [
      "export slow"
    ],
    "communities": [
      "r/example"
    ]
  },
  "posts": []
}
```

Troubleshooting

Cursor troubleshooting

The server shows a red status: Check that mcp.json is valid JSON and the Authorization value is Bearer rdb_..., with a space after Bearer. Toggle the server off and on after fixing.
Tools do not appear in the agent: Make sure you are in Agent mode and the server is enabled in Settings, MCP. Open a new chat after changing the config.
I do not want the key in a committed file: Put the config in the global ~/.cursor/mcp.json, or add .cursor/mcp.json to .gitignore. Never commit a key.
Budget or rate limit errors: Check usage under Settings, API keys. Each key allows 30 calls per minute.

Frequently asked questions

Back to the Reddinbox MCP overview

Connect Cursor to real conversations

Create a key, paste the config and ask your first question.

Get your API key I already have an account

Free trial. No credit card required.

Add the Reddinbox MCP server to Cursor

Set up Cursor step by step

Create an API key

Create or edit mcp.json

Enable the server

Use it in the agent

First prompts to try

What Cursor can call

Cursor troubleshooting

Frequently asked questions

Related pages

Connect Cursor to real conversations

Stop Guessing What Your Audience Wants