diff --git a/README.md b/README.md
index dfdfbf2..0731525 100644
--- a/README.md
+++ b/README.md
@@ -152,8 +152,10 @@ Say "eli5 on" after any research run. The synthesis rewrites in plain language.
 
 - **Free Reddit comments.** Public JSON gives you threads + top comments with upvote counts. No API key, no ScrapeCreators. Just works.
 - **YouTube transcripts that actually work.** Widened candidate pool 3x past music videos to reach talk/review content with captions.
-- **Threads, Pinterest, YouTube + TikTok comments.** Opt-in sources via ScrapeCreators. Set `INCLUDE_SOURCES=tiktok,instagram` and add threads, pinterest, youtube_comments, tiktok_comments for more. `youtube_comments` and `tiktok_comments` surface top comments with vote counts the same way Reddit does.
-- **Perplexity Sonar.** Grounded web search with citations via OpenRouter. Add `OPENROUTER_API_KEY` to unlock.
+- **TikTok, Instagram, Threads.** All three activate automatically once `SCRAPECREATORS_API_KEY` is set — same key, same per-call cost. Suppress any of them with `EXCLUDE_SOURCES=tiktok,instagram,threads` (any comma-separated subset).
+- **Pinterest.** Per-query opt-in (visual pins, narrow utility): the model passes `--search=pinterest` for the runs that need it. Requires `SCRAPECREATORS_API_KEY`.
+- **YouTube + TikTok comments.** Persistent opt-in via `INCLUDE_SOURCES=youtube_comments,tiktok_comments` because each video pulls N extra ScrapeCreators calls on top of the base search. Surface top comments with vote counts the same way Reddit does.
+- **Perplexity Sonar.** Grounded web search with citations via OpenRouter. Add `OPENROUTER_API_KEY` and `INCLUDE_SOURCES=perplexity` (it's a separate paid API — opt-in keeps you from being surprise-billed).
 - **Polymarket noise filtering.** Common-word disambiguation prevents "Apple" from matching "Will Apple release a car?"
 - **Resilient Reddit.** Timeout budgets and runtime fallback. One slow thread doesn't kill the whole run.
 - **Fun judge v2.** Humor scoring baked into the narrative. Reddit's cleverest one-liners mixed into the synthesis where they fit, not dumped in a separate section.
diff --git a/skills/last30days/SKILL.md b/skills/last30days/SKILL.md
index 16f89b6..a6c6b03 100644
--- a/skills/last30days/SKILL.md
+++ b/skills/last30days/SKILL.md
@@ -330,12 +330,10 @@ Common patterns:
 - If digg-pp-cli is installed (check `which digg-pp-cli`): add Digg
 - If AUTH_TOKEN/CT0 or XAI_API_KEY or FROM_BROWSER is set, or xurl CLI is installed and authenticated: add X
 - If yt-dlp is installed (check `which yt-dlp`): add YouTube
-- If SCRAPECREATORS_API_KEY is set and INCLUDE_SOURCES contains tiktok: add TikTok
-- If SCRAPECREATORS_API_KEY is set and INCLUDE_SOURCES contains instagram: add Instagram
-- If SCRAPECREATORS_API_KEY is set and INCLUDE_SOURCES contains threads: add Threads
-- If SCRAPECREATORS_API_KEY is set and INCLUDE_SOURCES contains pinterest: add Pinterest
+- If SCRAPECREATORS_API_KEY is set: add TikTok, Instagram, Threads (suppress any of these via EXCLUDE_SOURCES)
+- If SCRAPECREATORS_API_KEY is set and the user explicitly requested pinterest for this query (e.g. via `--search=pinterest`): add Pinterest
 - If BSKY_HANDLE and BSKY_APP_PASSWORD are set: add Bluesky
-- If OPENROUTER_API_KEY is set: add Perplexity
+- If OPENROUTER_API_KEY is set and INCLUDE_SOURCES contains perplexity: add Perplexity
 - If EXCLUDE_SOURCES is set (comma-separated, case-insensitive): drop any matching source from the list above before displaying
 
 Then display (use "and more" if 5+ sources, otherwise list all with Oxford comma):
diff --git a/skills/last30days/scripts/lib/env.py b/skills/last30days/scripts/lib/env.py
index 58751a4..870b75a 100644
--- a/skills/last30days/scripts/lib/env.py
+++ b/skills/last30days/scripts/lib/env.py
@@ -584,12 +584,12 @@ def _parse_include_sources(config: dict[str, Any]) -> set[str]:
 def is_threads_available(config: dict[str, Any]) -> bool:
     """Check if Threads source is available.
 
-    Requires SCRAPECREATORS_API_KEY AND 'threads' in INCLUDE_SOURCES.
-    Threads is an opt-in source - it is not activated by default.
+    Returns True when SCRAPECREATORS_API_KEY is set. Threads runs alongside
+    TikTok and Instagram as part of the SC family — same key, same per-call
+    cost shape, so the same default-on rule applies. Suppress via
+    EXCLUDE_SOURCES=threads.
     """
-    if not config.get('SCRAPECREATORS_API_KEY'):
-        return False
-    return 'threads' in _parse_include_sources(config)
+    return bool(config.get('SCRAPECREATORS_API_KEY'))
 
 
 def is_instagram_available(config: dict[str, Any]) -> bool:
diff --git a/tests/test_env_v3.py b/tests/test_env_v3.py
index a79ec69..b2a1f51 100644
--- a/tests/test_env_v3.py
+++ b/tests/test_env_v3.py
@@ -42,5 +42,25 @@ class EnvV3Tests(unittest.TestCase):
                 self.assertIsNone(bird_x.is_bird_authenticated())
 
 
+class ThreadsAvailabilityTests(unittest.TestCase):
+    """Threads is in the SC default-on family: same key, same per-call cost
+    shape as TikTok / Instagram, so the same default-on rule applies.
+    Suppression goes through EXCLUDE_SOURCES, not gated opt-in."""
+
+    def test_threads_available_with_sc_key_only(self):
+        self.assertTrue(env.is_threads_available({"SCRAPECREATORS_API_KEY": "k"}))
+
+    def test_threads_unavailable_without_sc_key(self):
+        self.assertFalse(env.is_threads_available({}))
+        self.assertFalse(env.is_threads_available({"INCLUDE_SOURCES": "threads"}))
+
+    def test_threads_does_not_require_include_sources(self):
+        """Regression guard: INCLUDE_SOURCES should not be needed."""
+        self.assertTrue(env.is_threads_available({
+            "SCRAPECREATORS_API_KEY": "k",
+            "INCLUDE_SOURCES": "",
+        }))
+
+
 if __name__ == "__main__":
     unittest.main()