reddit-fetch

name	reddit-fetch
description	Fetch content from Reddit using the curl JSON API. Use when accessing Reddit URLs, researching topics on Reddit, or when Reddit returns 403/blocked errors.

Reddit Fetch

Reddit's public JSON API works by appending .json to any Reddit URL.

Listing hot/new/top posts

curl -s -L -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36" \
  "https://old.reddit.com/r/SUBREDDIT/hot.json?limit=15"

Replace hot with new, top, or rising as needed. For top, add &t=day (or week, month, year, all).

Fetching a specific post + comments

curl -s -L -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36" \
  "https://old.reddit.com/r/SUBREDDIT/comments/POST_ID.json?limit=20"

The response is a JSON array: [0] is the post, [1] is the comment tree.

Searching within a subreddit

curl -s -L -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36" \
  "https://old.reddit.com/r/SUBREDDIT/search.json?q=QUERY&restrict_sr=on&sort=new&limit=15"

Parsing the JSON

Use jq to extract what you need:

# List posts
curl -s -L -o /tmp/reddit_result.txt -w "%{http_code}" \
  -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36" \
  'https://old.reddit.com/r/SUBREDDIT/hot.json?limit=15'

jq -r '.data.children[] | .data | "\(.title)\n   \(.score) pts | \(.num_comments) comments | u/\(.author) | id: \(.id)\n"' /tmp/reddit_result.txt

# List comments from a specific post (the [1] element has comments)
jq -r '.[1].data.children[] | select(.kind == "t1") | .data | "u/\(.author) (\(.score) pts):\n  \(.body[:300])\n"' /tmp/reddit_thread.txt

Key details:

• Fetch to temp file first, then parse - avoids pipe-related encoding issues
• -o /tmp/file and -w "%{http_code}" saves the response and prints the HTTP status (useful for debugging empty responses)
• -L follows redirects (old.reddit.com sometimes redirects)
• Single-quoted URL avoids shell interpretation of & in query strings
• .body[:300] truncates long comment bodies (jq 1.7+)

Rate limiting

Reddit's JSON API rate-limits aggressively:

• Don't fire parallel requests. Make them sequentially with sleep 2 or sleep 3 between each.
• If a request returns empty (0 bytes), wait 3-5 seconds and retry.
• If you get HTTP 429, back off for 10-15 seconds.
• A good pattern: fetch one search result listing, parse it, then fetch individual threads one at a time with delays.

Fallback: browser when the JSON API is blocked

The curl JSON API is the default - try it first. But Reddit sometimes returns HTTP 403 to curl (including from datacenter IPs like safeclaw containers), and retrying/backing off won't fix it. When that happens, switch to a real browser - the same .json URLs load fine in a browser session.

Order to try: curl (host) → curl (safeclaw container) → browser fallback.

Option A: Playwright (preferred)

Navigate to the .json URL and parse document.body.innerText as JSON - same response shape as curl, so the same [0]=post / [1]=comments structure applies.

1. mcp__playwright__browser_navigate to e.g. https://www.reddit.com/r/SUBREDDIT/search.json?q=QUERY&restrict_sr=on&sort=new&t=month&limit=25
2. mcp__playwright__browser_evaluate with a function that does JSON.parse(document.body.innerText) and maps out the fields you need, e.g.:

   () => {
     const data = JSON.parse(document.body.innerText);
     return data.data.children.map(c => ({
       t: c.data.title, s: c.data.score, n: c.data.num_comments, id: c.data.id
     }));
   }
   

3. For a thread, navigate to .../comments/POST_ID.json?limit=30&sort=top and parse data[0] (post) and data[1].data.children (comments).

Use www.reddit.com (not old.reddit.com) for browser navigation. Wrap the parse in try/catch and return document.body.innerText.slice(0,200) on failure so you can see what came back (e.g. a block page).

Option B: Claude for Chrome

If Playwright isn't available, use Claude for Chrome to open the .json URL (or the normal thread page) and read the content off the page.