diff --git a/app/main.py b/app/main.py
index f869879..dd8c2a3 100644
--- a/app/main.py
+++ b/app/main.py
@@ -65,6 +65,13 @@ OC_TOKEN_URL = "https://opencollective.com/oauth/token"
 OC_GRAPHQL_URL = "https://opencollective.com/api/graphql/v2"
 OC_COLLECTIVE_SLUG = os.environ.get("OC_COLLECTIVE_SLUG", "inference-cooperative")
 
+# Personal token for the "Inference Co-op Bot" account, which is an admin of
+# the collective. Authenticated as an admin, the GraphQL API exposes member
+# emails (which are hidden from anonymous access). We use this to match a
+# member by email — the stable identifier that works even for guest
+# contributors (who have no Open Collective account and thus no usable slug).
+OC_PERSONAL_TOKEN = os.environ.get("OC_PERSONAL_TOKEN", "")
+
 # Monthly credit budget (in USD of tokens) for all members.
 # Single sliding-scale tier: everyone gets the same $15/month in credits,
 # regardless of their $10/15/20 contribution. Governance decision (Loomio).
@@ -156,29 +163,54 @@ def is_pending_member(slug: str) -> bool:
     return row is not None
 
 
-async def is_active_member(slug: str) -> bool:
-    """Check the LIVE Open Collective membership list (authoritative source of
-    truth) for whether this slug is a financial contributor (BACKER/ADMIN),
-    not just the fiscal host. More reliable than the webhook, which only fires
-    on new events and can miss existing members."""
-    if not slug:
-        return False
+async def fetch_member_emails() -> dict[str, str]:
+    """Return a map of email -> role for active financial contributors.
+
+    Uses the bot's personal token (admin) so the GraphQL API exposes member
+    emails, which are hidden from anonymous access. This is the authoritative
+    source of truth for "who is a member" — and it works for guest
+    contributors (who have no OC account) because their email is still in the
+    list.
+    """
+    if not OC_PERSONAL_TOKEN:
+        logger.warning("OC_PERSONAL_TOKEN not set; cannot fetch member emails")
+        return {}
     query = (
-        '{ collective(slug: "%s") { members(limit: 100) { nodes { role account { slug } } } } }'
+        '{ collective(slug: "%s") { members(limit: 100) { nodes { role account { email } } } } }'
         % OC_COLLECTIVE_SLUG
     )
     async with httpx.AsyncClient() as client:
-        r = await client.post(OC_GRAPHQL_URL, json={"query": query})
+        r = await client.post(
+            OC_GRAPHQL_URL,
+            headers={"Personal-Token": OC_PERSONAL_TOKEN},
+            json={"query": query},
+        )
         if r.status_code != 200:
-            logger.warning("OC membership check failed: %s", r.status_code)
-            return False
+            logger.warning("OC member fetch failed: %s", r.status_code)
+            return {}
         nodes = r.json().get("data", {}).get("collective", {}).get("members", {}).get("nodes", [])
+    result: dict[str, str] = {}
     for n in nodes:
         role = n.get("role", "")
         acct = n.get("account", {}) or {}
-        if acct.get("slug") == slug and role in ("BACKER", "ADMIN"):
-            return True
-    return False
+        email = (acct.get("email") or "").strip().lower()
+        if email and role in ("BACKER", "ADMIN"):
+            result[email] = role
+    return result
+
+
+async def is_active_member(email: str) -> bool:
+    """Check whether this email is an active financial contributor.
+
+    Matches on email (not slug) so guest contributors — who have no OC account
+    and thus no usable slug — are still recognized. The email comes from the
+    OAuth `me` query (with the user's consent); we match it against the
+    admin-visible member list.
+    """
+    if not email:
+        return False
+    members = await fetch_member_emails()
+    return email.strip().lower() in members
 
 
 async def get_active_member_emails() -> list[str]:
@@ -667,9 +699,10 @@ async def oauth_callback(request: Request):
 
     # Gate: only provision if this person is an active financial contributor.
     # We check the LIVE Open Collective membership list (authoritative), not
-    # the webhook's pending table (which only fires on new events).
-    if not await is_active_member(slug):
-        logger.warning("Rejected non-member %s (slug=%s not an active contributor)", email, slug)
+    # the webhook's pending table (which only fires on new events). Matching is
+    # by email so guest contributors (no OC account) are still recognized.
+    if not await is_active_member(email):
+        logger.warning("Rejected non-member %s (email not an active contributor)", email)
         html = """<!DOCTYPE html>
 <html lang="en">
 <head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0">