diff --git a/backfill.py b/backfill.py
new file mode 100755
index 0000000000..425b75cca9
--- /dev/null
+++ b/backfill.py
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+#!/usr/bin/env python2 -u
+"""Script for backfilling exchange status, route, and ref.
+
+Symlink a directory of data at `./backfill` and then call like so:
+
+    [gratipay] $ run_dammit defaults.env local.env -c env/bin/python backfill.py
+
+Data files should be one per network (named `samurai`, `stripe`, etc), as CSVs
+with these columns:
+
+    user_id         required    Gratipay participant.id
+    username        ignored
+    address         optional    defaults to 'fake-deadbeef'
+    exchange_id     required    Gratipay exchanges.id
+    status          optional    defaults to 'succeeded'
+    ref             optional    defaults to 'fake-beeffeed'
+
+For successfully backfilled exchanges (and routes), the script outputs the same
+CSV as was input, with optional fields filled in. The script is idempotent (the
+faked address and ref are hashed from other input values).
+
+"""
+from __future__ import absolute_import, division, print_function, unicode_literals
+
+import csv
+import os
+import sha
+import sys
+from os import path
+
+from gratipay import wireup
+from gratipay.models.exchange_route import ExchangeRoute
+from gratipay.models.participant import Participant
+
+
+BASE = path.dirname(__file__)
+
+
+def fake(*a):
+    return 'fake-' + sha.new(''.join(map(str, a))).hexdigest()
+
+
+def link(db, log, user_id, network, address, exchange_id, status, ref):
+    participant = Participant.from_id(user_id)
+    route = ExchangeRoute.from_network(participant, network)
+    if route is None:
+        route = ExchangeRoute.insert(participant, network, address)
+    db.run( "UPDATE exchanges SET status=%s, route=%s, ref=%s WHERE id=%s"
+          , (status, route.id, ref, exchange_id)
+           )
+    log(participant.id, participant.username, address, exchange_id, status, ref )
+
+
+def main(db, log):
+    for network in os.listdir('backfill'):
+        data = csv.reader(open(path.join('backfill', network)))
+        for user_id, _, address, exchange_id, status, ref in data:
+            assert user_id
+            address = address or fake(user_id, network)
+            assert exchange_id
+            status = status or 'succeeded'
+            ref = ref or fake(user_id, network, exchange_id)
+
+            link(db, log, user_id, network, address, exchange_id, status, ref)
+
+
+if __name__ == '__main__':
+    db = wireup.db(wireup.env())
+    writer = csv.writer(sys.stdout)
+    log = lambda *a: writer.writerow(a)
+    main(db, log)
diff --git a/sql/branch.sql b/sql/branch.sql
new file mode 100644
index 0000000000..74a9f6fd6e
--- /dev/null
+++ b/sql/branch.sql
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+ALTER TYPE payment_net ADD VALUE 'samurai';
+ALTER TYPE payment_net ADD VALUE 'stripe';
+
+ALTER TABLE exchanges ADD UNIQUE (ref);