diff --git a/.editorconfig b/.editorconfig
index 49df4e5..24c93ee 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -6,8 +6,8 @@ root = true
 end_of_line = lf
 insert_final_newline = true
 trim_trailing_whitespace = true
-indent_style = space
-indent_size = 4
+indent_style = tab
+indent_size = 2
 
 # Markdown
 [*.md]
diff --git a/README.md b/README.md
index 94565d6..5da3e81 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,7 @@ Configuring mstdn-ebooks is accomplished by editing `config.json`.
 | instance_blacklist | ["bofa.lol", "witches.town"] | If your bot is following someone from a blacklisted instance, it will skip over them and not download their posts. This is useful for ensuring that mstdn-ebooks doesn't download posts from dead instances, without you having to unfollow the user(s) from them. |
 | learn_from_cw | false |  If true, mstdn-ebooks will learn from CW'd posts. |
 | mention_handling | 1 |  0: Never use mentions. 1: Only generate fake mentions in the middle of posts, never at the start. 2: Use mentions as normal (old behaviour). |
+| max_thread_length | 15 | The maximum number of bot posts in a row before it stops replying. A thread can be 10 or 10000 posts long, but the bot will stop after it has posted `max_thread_length` times. |
 
 
 ## Original README
diff --git a/config.json b/config.json
index 82bd508..c065575 100644
--- a/config.json
+++ b/config.json
@@ -1,7 +1,8 @@
 {
-    "lang": "en",
+	"lang": "en",
 	"site": "https://botsin.space",
 	"cw": null,
 	"learn_from_cw": false,
-	"mention_handling": 1
+	"mention_handling": 1,
+	"max_thread_length": 15
 }
diff --git a/main.py b/main.py
index 70192d3..877d482 100755
--- a/main.py
+++ b/main.py
@@ -19,6 +19,7 @@ cfg = {
 	"instance_blacklist": ["bofa.lol", "witches.town"],
 	"learn_from_cw": False,
 	"mention_handling": 1,
+	"max_thread_length": 15
 }
 try:
 	cfg.update(json.load(open('config.json', 'r')))
diff --git a/reply.py b/reply.py
index 2e60de1..3298c84 100755
--- a/reply.py
+++ b/reply.py
@@ -9,6 +9,7 @@ import functions
 from bs4 import BeautifulSoup
 
 cfg = json.load(open('config.json', 'r'))
+threads = {}
 
 client = mastodon.Mastodon(
   client_id=cfg['client']['id'],
@@ -27,6 +28,23 @@ class ReplyListener(mastodon.StreamListener):
 		if notification['type'] == 'mention': #if we're mentioned:
 			acct = "@" + notification['account']['acct'] #get the account's @
 			post_id = notification['status']['id']
+			# check if we've already been participating in this thread
+			try:
+				context = client.status_context(post_id)
+			except:
+				print("failed to fetch thread context")
+				return
+			me = client.account_verify_credentials()['id']
+			posts = 0
+			for post in context['ancestors']:
+				if post['account']['id'] == me:
+					posts += 1
+					if posts >= cfg['max_thread_length']:
+						# stop replying
+						print("didn't reply (max_thread_length exceeded)")
+						return
+
+				threads[post_id] = [time.time(), 0]
 			mention = extract_toot(notification['status']['content'])
 			toot = functions.make_toot(True)['toot'] #generate a toot
 			toot = acct + " " + toot #prepend the @