Reddit mentions to Slack with n8n

Every day Slack gets one message per new public Reddit post that matches your keyword: title, score and link. Posts already sent are skipped twice over, by the Actor's own monitor and by the workflow, so a thread appears once.

Put your brand, product or topic in the keywords list. The monitorId keeps the Actor's memory of what it already returned; keep it unchanged between runs.

Run on Apify

Built-in nodes only Imports on n8n Cloud and self-hosted n8n 1.80 or later, no community nodes. 11 of 11 checks pass; validated, not executed.

Source: Reddit
Actor: Reddit Keyword Search with Advanced Filters
Destination: Slack
Store price: $0.99 per 1,000 results (pay per event)
Cost on the Free plan: about $0.12 a run (start $0.10 + about 25 results; the input sets no limit, so more results cost more), about $3.74 a month daily, plus platform usage
Data checked: 2026-11-12

Method

Get an Apify token

Sign in to Apify and copy a personal API token from Console: Settings, API and integrations. The workflow keeps it in an n8n credential, never in the file.

Import the workflow

In n8n choose Workflows, Import from file, or paste the JSON onto an empty canvas.

Run by hand
Every day
Run Apify Actor
Only records not sent before
Send to Slack

n8n workflowreddit-mentions-to-slack.n8n.json

Actor on Apify

Show the file (172 lines)

{
  "name": "Reddit mentions to Slack",
  "nodes": [
    {
      "id": "4ec12ece-b628-43f1-a521-5c8cfdbfdbe3",
      "name": "Run by hand",
      "type": "n8n-nodes-base.manualTrigger",
      "typeVersion": 1,
      "position": [
        0,
        0
      ],
      "parameters": {}
    },
    {
      "id": "5b1e5d46-3427-4473-a77d-50e69a891a7b",
      "name": "Every day",
      "type": "n8n-nodes-base.scheduleTrigger",
      "typeVersion": 1.2,
      "position": [
        0,
        200
      ],
      "parameters": {
        "rule": {
          "interval": [
            {
              "triggerAtHour": 8
            }
          ]
        }
      },
      "notes": "Activate the workflow to run on this schedule."
    },
    {
      "id": "7f394cba-414a-43e8-a8dd-42913bf403f7",
      "name": "Run Apify Actor",
      "type": "n8n-nodes-base.httpRequest",
      "typeVersion": 4.2,
      "position": [
        260,
        100
      ],
      "parameters": {
        "method": "POST",
        "url": "https://api.apify.com/v2/actors/nimbryxo-studio~reddit-keyword-search-with-advanced-filters/run-sync-get-dataset-items",
        "authentication": "genericCredentialType",
        "genericAuthType": "httpHeaderAuth",
        "sendBody": true,
        "specifyBody": "json",
        "jsonBody": "{\n  \"keywords\": [\n    \"n8n\"\n  ],\n  \"onlyNew\": true,\n  \"searchComments\": false,\n  \"excludeNsfw\": false,\n  \"keywordRequireAll\": false,\n  \"includeArchive\": true,\n  \"resolveChallenges\": true,\n  \"monitorId\": \"reddit-mentions-slack\",\n  \"sort\": \"new\",\n  \"relativeWindow\": \"week\"\n}",
        "options": {
          "timeout": 310000
        }
      },
      "notes": "Actor: nimbryxo-studio/reddit-keyword-search-with-advanced-filters. Select a Header Auth credential: name Authorization, value Bearer + your Apify token. Edit the JSON body to change the input.",
      "notesInFlow": false
    },
    {
      "id": "40d298fe-04d0-44b1-a1b9-2c4c5776851b",
      "name": "Only records not sent before",
      "type": "n8n-nodes-base.removeDuplicates",
      "typeVersion": 2,
      "position": [
        500,
        100
      ],
      "parameters": {
        "operation": "removeItemsSeenInPreviousExecutions",
        "logic": "removeItemsWithAlreadySeenKeyValues",
        "dedupeValue": "={{ $json.url }}",
        "options": {
          "scope": "node",
          "historySize": 10000
        }
      },
      "notes": "Remembers each url it has passed on (up to 10,000) across runs, so a record is sent once. Needs n8n 1.64 or later."
    },
    {
      "id": "4559b7ee-08e3-467b-a88d-e3aae92379a3",
      "name": "Send to Slack",
      "type": "n8n-nodes-base.slack",
      "typeVersion": 2.3,
      "position": [
        740,
        100
      ],
      "parameters": {
        "select": "channel",
        "channelId": {
          "__rl": true,
          "value": "",
          "mode": "list"
        },
        "text": "={{ [$json.title, $json.score, $json.url].filter(v => v !== undefined && v !== null && v !== '').join(' | ') }}",
        "otherOptions": {}
      },
      "notes": "Pick your Slack credential and channel."
    },
    {
      "id": "ee0acd06-3495-47b7-ab3e-d5964dfc448b",
      "name": "Setup",
      "type": "n8n-nodes-base.stickyNote",
      "typeVersion": 1,
      "position": [
        0,
        -370
      ],
      "parameters": {
        "content": "## Reddit Keyword Search with Advanced Filters\n\nSource: [nimbryxo-studio/reddit-keyword-search-with-advanced-filters](https://apify.com/nimbryxo-studio/reddit-keyword-search-with-advanced-filters) on Apify.\n\n1. In **Run Apify Actor**, create a Header Auth credential: name `Authorization`, value `Bearer YOUR_APIFY_TOKEN` with your token.\n2. Open **Send to Slack** and connect your Slack account.\n3. Edit the JSON body of **Run Apify Actor** to change the input.\n\nGenerated by recipeforagents.com. Validated, not executed: runs are billed to your Apify account.",
        "height": 340,
        "width": 460,
        "color": 6
      }
    }
  ],
  "connections": {
    "Run by hand": {
      "main": [
        [
          {
            "node": "Run Apify Actor",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Every day": {
      "main": [
        [
          {
            "node": "Run Apify Actor",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Run Apify Actor": {
      "main": [
        [
          {
            "node": "Only records not sent before",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Only records not sent before": {
      "main": [
        [
          {
            "node": "Send to Slack",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  },
  "pinData": {},
  "active": false,
  "settings": {
    "executionOrder": "v1"
  },
  "meta": {
    "templateCredsSetupCompleted": false
  },
  "tags": []
}

Validated, not executed: 11 of 11 checks pass

It has a nodes array and a connections object
Every node has a name, type, typeVersion, position and parameters
Node names are unique
Every node type is a known n8n core node (or the Apify node)
Every node uses a typeVersion that n8n ships
Every connection points at an existing node
At least one trigger starts the workflow
Every working node is reachable from a trigger
Apify calls use POST and a credential for the token
Actor input matches the Actor's published input schema
No token or credential value is embedded

Add the Apify credential

Open Run Apify Actor. Under Credential, create a Header Auth credential with the name Authorization and the value Bearer, a space and your token.

Set the input

The request body holds the Actor input: the Actor's Store prefill with keywords, onlyNew, monitorId set for this recipe. Change keywords and onlyNew to your own.

{
  "keywords": [
    "n8n"
  ],
  "onlyNew": true,
  "searchComments": false,
  "excludeNsfw": false,
  "keywordRequireAll": false,
  "includeArchive": true,
  "resolveChallenges": true,
  "monitorId": "reddit-mentions-slack",
  "sort": "new",
  "relativeWindow": "week"
}

Every input field is documented on the Reddit Keyword Search with Advanced Filters page.

Only new records go through

The Only records not sent before node (n8n's Remove Duplicates, set to remove items processed in previous executions) remembers each url it has passed on, so a record reaches Slack once even when the next run returns it again. It needs n8n 1.64 or later; clear its history from the node to resend everything.
Connect Slack

Open Send to Slack, select your Slack credential and pick the channel. Each message shows title, score, url.
Run once, then turn it on

Click Execute workflow and check the first records in Slack. When they look right, activate the workflow so the daily trigger runs it at 08:00 in your instance's timezone.

Where it breaks

Reddit's search matches words in titles and post text; mentions only in comments need searchComments switched on.
Very common words return noise; quote exact phrases or add a subreddit filter.
Reddit is changing public data access over the coming months, so check the Actor page if results thin out.
The workflow uses Apify's synchronous endpoint, which waits up to 300 seconds. Bigger runs answer HTTP 408: lower the limit or switch to an asynchronous run.
Each run is billed to your Apify account at the Store price ($0.99 per 1,000 results (pay per event)).

Bigger runs: the long-run workflow starts the run, waits for it and reads the dataset, so it never hits the 300-second limit.

If the workflow fails

Why does the workflow or script stop with HTTP 408?

The synchronous endpoint waits at most 300 seconds. After that it answers 408 while the run keeps going in Apify. Lower the result limit, or start the run asynchronously, wait for it to finish and then read its dataset.

Source: Apify API: run Actor synchronously and get dataset items

What do 400, 401, 402 and 403 from the Apify API mean?

Read error.type in the response body. 400 is invalid Actor input. 401 (user-or-token-not-found) means a token reached Apify but it is wrong or revoked. 402 with x402-payment-required means no token reached Apify at all: the n8n credential or the Authorization: Bearer header is missing, and Apify is offering its pay-per-run x402 route for agents instead; any other 402 is an exhausted usage limit on the account that pays for the run. 403 is a token without permission for that Actor or storage.

Source: Apify API: authentication; Apify documentation: agentic payments with x402; Apify API: run Actor synchronously and get dataset items

n8n says Install this node to use it after import. Why?

The workflow names a node or node version your instance does not have, usually a community node. The workflows here use only built-in nodes at versions n8n has shipped since 1.80, so they import on n8n Cloud and older self-hosted instances without community nodes.

Source: n8n issue: unrecognized node type after import

Why does the HTTP Request node time out before Apify answers?

Set the node's Timeout option to at least 300000 ms so n8n waits as long as Apify's synchronous endpoint. The workflows here already set 310000. A failure at exactly 30 seconds points to a proxy in front of n8n.

Source: n8n HTTP Request node documentation

Every fix in one place

Same data in an agent

Want Claude, Cursor or ChatGPT to call the Actor directly instead of on a schedule? The Reddit Keyword Search with Advanced Filters page has MCP configs for eight clients and a SKILL.md. The Reddit MCP server bundles every Reddit Actor in one URL.

Questions

Can it watch several keywords?

Yes. Add them to the keywords list and each runs as its own search. Matches from all of them arrive in the same channel.

Does it include comments?

Only when searchComments is on in the request body. Comment matches then arrive as their own messages with a link to the thread.

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Reddit mentions to Slack with n8n

Method

Get an Apify token

Import the workflow

n8n workflowreddit-mentions-to-slack.n8n.json

Add the Apify credential

Set the input

Only new records go through

Connect Slack

Run once, then turn it on

Where it breaks

If the workflow fails

Same data in an agent

Questions

More recipes

Reddit posts to Google Sheets

Reddit keyword monitor to Discord

Reddit weekly digest to email

Google Maps competitor scan to Slack

LinkedIn company posts to Slack

Zillow new listings to Slack