Auto-suspend creators with shared ACH bank accounts (stripe fingerprints) by yashranaway · Pull Request #2810 · antiwork/gumroad

yashranaway · 2026-01-10T07:29:14Z

Fixes : #1158

Description

Problem

We currently auto-suspend accounts that share the same PayPal payout address as another suspended account. However, fraudsters are increasingly using shared ACH bank accounts (identified by Stripe fingerprints) across multiple accounts. When one account gets suspended, the related accounts using the same bank account slip through undetected, leading to more chargebacks and time spent hunting down fraudsters manually.

Solution

Extended the existing PayPal-based auto-suspension system to also handle Stripe bank account fingerprints:

When an admin suspends an account:

Find all other accounts using the same bank account fingerprint
Flag them for fraud and suspend them automatically
Add comments explaining why they were suspended and which account triggered it

When a new account sets up a bank account:

Check if the fingerprint matches any suspended account's bank account
Also check if the fingerprint is explicitly blocked
Flag the account for fraud if there's a match

When an account is marked compliant:

Related accounts with the same fingerprint are also marked compliant

I also addressed several edge cases that improve on the original PayPal implementation:

Checks ALL bank account fingerprints (not just the active one) since a fraudster might have multiple accounts
Preserves fraud history even if the suspended user deletes their bank account
Skips already suspended users to avoid duplicate processing
Added a database index on stripe_fingerprint for performance

Test Results

Checklist

I have read the contributing guidelines
I have watched Gumroad PR review livestreams
I have performed a self-review and left review comments on my PR
I have added/updated tests for my changes

AI Disclosure

Claude Opus 4.5 was used to assist with implementing this feature via Claude Code.

yashranaway · 2026-01-10T07:31:40Z

+  def enable_accounts_with_same_stripe_fingerprint
+    fingerprints = bank_accounts.where.not(stripe_fingerprint: [nil, ""]).pluck(:stripe_fingerprint).uniq
+    return if fingerprints.empty?


Same pattern as the suspend worker - checking all bank accounts (including deleted) to find all fingerprints this user has ever used.

yashranaway · 2026-01-10T07:32:06Z

+      matching_fingerprint = (fingerprints & user.alive_bank_accounts.pluck(:stripe_fingerprint)).first
+      user.mark_compliant!(author_name: "enable_sellers_other_accounts", content: "Marked compliant automatically on #{Time.current.to_fs(:formatted_date_full_month)} as bank account fingerprint #{matching_fingerprint} is now unblocked")


Finding the specific matching fingerprint for an accurate admin comment.

yashranaway · 2026-01-10T07:32:27Z

    bank_account.stripe_fingerprint = stripe_external_account.fingerprint
    bank_account.save!
+
+    CheckPaymentAddressWorker.perform_async(bank_account.user_id)


This triggers the fraud check right after Stripe gives us the fingerprint. Mirrors how PayPal triggers the check in UpdatePayoutMethod when a payment address is set.

yashranaway · 2026-01-10T07:32:56Z

Adding an index since we're now querying by fingerprint. Should help with performance when we have many bank accounts.

yashranaway · 2026-01-10T07:33:46Z


-    return if suspended_user.payment_address.blank?
+    suspend_users_with_same_payment_address(suspended_user)
+    suspend_users_with_same_stripe_fingerprint(suspended_user)


After checking PayPal addresses, we now also check for matching Stripe fingerprints.

yashranaway · 2026-01-10T07:34:50Z

+      User.where(id: user_ids_with_same_fingerprint).find_each do |user|
+        next if user.suspended?
+
+        matching_fingerprint = (fingerprints & user.alive_bank_accounts.pluck(:stripe_fingerprint)).first


When the suspended user has multiple fingerprints, we find which specific one matched so the admin comment is accurate.

yashranaway · 2026-01-10T07:35:17Z

  include Sidekiq::Job
  sidekiq_options retry: 0, queue: :default

+  SUSPENDED_STATES = %w[suspended_for_tos_violation suspended_for_fraud].freeze


Extracted this constant to avoid repetition and make it clearer what states we're checking for.

This constant would be better off being defined in the User::Risk module and invoked here

yashranaway · 2026-01-10T07:35:26Z

+    end
+
+    def stripe_fingerprint_matches_suspended_account?(user)
+      fingerprints = user.alive_bank_accounts.where.not(stripe_fingerprint: [nil, ""]).pluck(:stripe_fingerprint).uniq


Checking all of the new user's fingerprints, not just their active bank account. A user might have multiple bank accounts.

yashranaway · 2026-01-10T07:35:48Z

+      suspended_accounts_with_same_fingerprint = BankAccount
+        .joins(:user)
+        .where(stripe_fingerprint: fingerprints)
+        .where.not(user_id: user.id)
+        .where(users: { user_risk_state: SUSPENDED_STATES })
+


Not filtering by .alive here - we intentionally check against ALL bank accounts (including deleted) from suspended users. This preserves fraud history even if fraudsters delete their accounts.

yashranaway · 2026-01-10T07:36:02Z

+        .where.not(user_id: user.id)
+        .where(users: { user_risk_state: SUSPENDED_STATES })
+
+      blocked_fingerprints = fingerprints.any? { |fp| BlockedObject.find_active_object(fp).present? }


Also checking BlockedObject for explicitly blocked fingerprints, same pattern as the PayPal email check.

You can query MongoDB once instead of one time per fingerprint

Suggested change

blocked_fingerprints = fingerprints.any? { |fp| BlockedObject.find_active_object(fp).present? }

blocked_fingerprints = BlockedObject.find_active_objects(fingerprints)

Can you verify this does not evaluate immediately? It would be better to not send the query to MongoDB if suspended_accounts_with_same_fingerprint.exists? is already true

Resolved conflicts in: - app/sidekiq/suspend_accounts_with_payment_address_worker.rb - app/modules/user/risk.rb Combined Stripe fingerprint detection with skip_transition_callback fix.

- Keep upstream's schema version (2026_11_19_011937) - Preserve stripe_fingerprint index on bank_accounts - Use upstream's integer type for default_offer_code_id

EmCousin

The implementation looks sound and well tested, I added a few comments addressing performance. I will also run CI now. Can you address them, and fix failing tests if we find some. Thanks!

EmCousin · 2026-01-27T12:09:03Z

  end

+  def enable_accounts_with_same_stripe_fingerprint
+    fingerprints = bank_accounts.where.not(stripe_fingerprint: [nil, ""]).pluck(:stripe_fingerprint).uniq


You can uniq the fingerprints in the database rather than in memory:

Suggested change

fingerprints = bank_accounts.where.not(stripe_fingerprint: [nil, ""]).pluck(:stripe_fingerprint).uniq

fingerprints = bank_accounts.where.not(stripe_fingerprint: [nil, ""]).distinct.pluck(:stripe_fingerprint)

EmCousin · 2026-01-27T12:10:19Z

+    user_ids_with_same_fingerprint = BankAccount.alive
+      .where(stripe_fingerprint: fingerprints)
+      .where.not(user_id: id)
+      .pluck(:user_id)
+      .uniq


Suggested change

user_ids_with_same_fingerprint = BankAccount.alive

.where(stripe_fingerprint: fingerprints)

.where.not(user_id: id)

.pluck(:user_id)

.uniq

user_ids_with_same_fingerprint = BankAccount.alive

.where(stripe_fingerprint: fingerprints)

.where.not(user_id: id)

.distinct

.pluck(:user_id)

EmCousin · 2026-01-27T12:17:27Z

  include Sidekiq::Job
  sidekiq_options retry: 0, queue: :default

+  SUSPENDED_STATES = %w[suspended_for_tos_violation suspended_for_fraud].freeze


This constant would be better off being defined in the User::Risk module and invoked here

EmCousin · 2026-01-27T12:24:50Z

+    end
+
+    def stripe_fingerprint_matches_suspended_account?(user)
+      fingerprints = user.alive_bank_accounts.where.not(stripe_fingerprint: [nil, ""]).pluck(:stripe_fingerprint).uniq


Suggested change

fingerprints = user.alive_bank_accounts.where.not(stripe_fingerprint: [nil, ""]).pluck(:stripe_fingerprint).uniq

fingerprints = user.alive_bank_accounts.where.not(stripe_fingerprint: [nil, ""]).distinct.pluck(:stripe_fingerprint)

EmCousin · 2026-01-27T12:29:29Z

+        .where.not(user_id: user.id)
+        .where(users: { user_risk_state: SUSPENDED_STATES })
+
+      blocked_fingerprints = fingerprints.any? { |fp| BlockedObject.find_active_object(fp).present? }


You can query MongoDB once instead of one time per fingerprint

Suggested change

blocked_fingerprints = fingerprints.any? { |fp| BlockedObject.find_active_object(fp).present? }

blocked_fingerprints = BlockedObject.find_active_objects(fingerprints)

EmCousin · 2026-01-27T12:30:15Z

+        .where.not(user_id: user.id)
+        .where(users: { user_risk_state: SUSPENDED_STATES })
+
+      blocked_fingerprints = fingerprints.any? { |fp| BlockedObject.find_active_object(fp).present? }


Can you verify this does not evaluate immediately? It would be better to not send the query to MongoDB if suspended_accounts_with_same_fingerprint.exists? is already true

EmCousin · 2026-01-27T12:31:07Z

+    end
+
+    def suspend_users_with_same_stripe_fingerprint(suspended_user)
+      fingerprints = suspended_user.bank_accounts.where.not(stripe_fingerprint: [nil, ""]).pluck(:stripe_fingerprint).uniq


Suggested change

fingerprints = suspended_user.bank_accounts.where.not(stripe_fingerprint: [nil, ""]).pluck(:stripe_fingerprint).uniq

fingerprints = suspended_user.bank_accounts.where.not(stripe_fingerprint: [nil, ""]).distinct.pluck(:stripe_fingerprint)

EmCousin · 2026-01-27T12:31:33Z

+        .pluck(:user_id)
+        .uniq


Suggested change

.pluck(:user_id)

.uniq

.distinct

.pluck(:user_id)

yashranaway · 2026-01-27T13:42:00Z

Can you verify this does not evaluate immediately? It would be better to not send the query to MongoDB if suspended_accounts_with_same_fingerprint.exists? is already true

@EmCousin _a Fixed in fd488a6 The code now uses an early return. Also the CI failures are unrelated

…nts) (antiwork#2810) Fixes : #1158 # Description ## Problem We currently auto-suspend accounts that share the same PayPal payout address as another suspended account. However, fraudsters are increasingly using shared ACH bank accounts (identified by Stripe fingerprints) across multiple accounts. When one account gets suspended, the related accounts using the same bank account slip through undetected, leading to more chargebacks and time spent hunting down fraudsters manually. ## Solution Extended the existing PayPal-based auto-suspension system to also handle Stripe bank account fingerprints: **When an admin suspends an account:** - Find all other accounts using the same bank account fingerprint - Flag them for fraud and suspend them automatically - Add comments explaining why they were suspended and which account triggered it **When a new account sets up a bank account:** - Check if the fingerprint matches any suspended account's bank account - Also check if the fingerprint is explicitly blocked - Flag the account for fraud if there's a match **When an account is marked compliant:** - Related accounts with the same fingerprint are also marked compliant I also addressed several edge cases that improve on the original PayPal implementation: - Checks ALL bank account fingerprints (not just the active one) since a fraudster might have multiple accounts - Preserves fraud history even if the suspended user deletes their bank account - Skips already suspended users to avoid duplicate processing - Added a database index on `stripe_fingerprint` for performance # Test Results <img width="781" height="237" alt="image" src="https://github.com/user-attachments/assets/8ac8199d-83ca-4c8d-9ea8-41cd1c438c81" /> --- # Checklist - [x] I have read the [contributing guidelines](https://github.com/antiwork/gumroad/blob/main/CONTRIBUTING.md) - [x] I have watched [Gumroad PR review livestreams](https://www.youtube.com/@anti-work) - [x] I have performed a self-review and left review comments on my PR - [x] I have added/updated tests for my changes --- # AI Disclosure Claude Opus 4.5 was used to assist with implementing this feature via Claude Code. --------- Co-authored-by: Emmanuel Cousin <[email protected]>

yashranaway and others added 2 commits January 10, 2026 12:53

fix

6d4bf22

Merge branch 'main' into feature/auto-suspend-shared-ach-accounts

3fe972c

yashranaway commented Jan 10, 2026

View reviewed changes

yashranaway marked this pull request as ready for review January 10, 2026 07:36

yashranaway added 2 commits January 12, 2026 14:16

Refactor account suspension logic to exclude already suspended users

db8f544

Merge main into feature/auto-suspend-shared-ach-accounts

896a0ed

Resolved conflicts in: - app/sidekiq/suspend_accounts_with_payment_address_worker.rb - app/modules/user/risk.rb Combined Stripe fingerprint detection with skip_transition_callback fix.

yashranaway had a problem deploying to ci-protected January 20, 2026 08:28 — with GitHub Actions Error

Update schema.rb with stripe_fingerprint index on bank_accounts

a010e04

yashranaway had a problem deploying to ci-protected January 21, 2026 18:08 — with GitHub Actions Error

Merge upstream/main and resolve schema.rb conflicts

a51a5e8

- Keep upstream's schema version (2026_11_19_011937) - Preserve stripe_fingerprint index on bank_accounts - Use upstream's integer type for default_offer_code_id

yashranaway had a problem deploying to ci-protected January 21, 2026 18:11 — with GitHub Actions Error

EmCousin reviewed Jan 27, 2026

View reviewed changes

Merge branch 'main' into feature/auto-suspend-shared-ach-accounts

b11cf2a

EmCousin had a problem deploying to ci-protected January 27, 2026 13:05 — with GitHub Actions Error

Review comments

fd488a6

yashranaway had a problem deploying to ci-protected January 27, 2026 13:37 — with GitHub Actions Failure

neetogit-bot Bot assigned EmCousin Jan 27, 2026

EmCousin approved these changes Jan 27, 2026

View reviewed changes

EmCousin merged commit 3e92cf5 into antiwork:main Jan 28, 2026
124 of 131 checks passed

This was referenced Jan 28, 2026

Automatically suspend creators w/ shared bank accounts (Stripe) #3182

Closed

feat(fraud): auto-suspend creators with shared ACH accounts #3183

Closed

yashranaway deleted the feature/auto-suspend-shared-ach-accounts branch January 28, 2026 09:40

		matching_fingerprint = (fingerprints & user.alive_bank_accounts.pluck(:stripe_fingerprint)).first
		user.mark_compliant!(author_name: "enable_sellers_other_accounts", content: "Marked compliant automatically on #{Time.current.to_fs(:formatted_date_full_month)} as bank account fingerprint #{matching_fingerprint} is now unblocked")

	blocked_fingerprints = fingerprints.any? { \|fp\| BlockedObject.find_active_object(fp).present? }
	blocked_fingerprints = BlockedObject.find_active_objects(fingerprints)

	fingerprints = bank_accounts.where.not(stripe_fingerprint: [nil, ""]).pluck(:stripe_fingerprint).uniq
	fingerprints = bank_accounts.where.not(stripe_fingerprint: [nil, ""]).distinct.pluck(:stripe_fingerprint)

	fingerprints = user.alive_bank_accounts.where.not(stripe_fingerprint: [nil, ""]).pluck(:stripe_fingerprint).uniq
	fingerprints = user.alive_bank_accounts.where.not(stripe_fingerprint: [nil, ""]).distinct.pluck(:stripe_fingerprint)

	fingerprints = suspended_user.bank_accounts.where.not(stripe_fingerprint: [nil, ""]).pluck(:stripe_fingerprint).uniq
	fingerprints = suspended_user.bank_accounts.where.not(stripe_fingerprint: [nil, ""]).distinct.pluck(:stripe_fingerprint)

Conversation

yashranaway commented Jan 10, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Description

Problem

Solution

Test Results

Checklist

AI Disclosure

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

EmCousin left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

yashranaway commented Jan 27, 2026

Uh oh!

Uh oh!

This branch had an error being deployed

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

yashranaway commented Jan 10, 2026 •

edited

Loading