Double charge after deploy: pre-release and first 30 minutes checklists

A customer is charged twice for one purchase after a release changes retry or idempotency behaviour.

The pre-release checklist maps each item to a test class from the incident page. The first-30-minutes checklist covers detection, containment, the rollback decision and customer communication.

8 pre-release items · 7 first-30-minutes items · verified 2026-10-22

Pre-release checklist

PR-01Register every response field the Ruby client library parses, including eligible_for_card_updater, as a consumer contract and fail the platform build when a deploy removes one. contract
PR-02Confirm that a response field removal ships only in a new API version while the current version's consumer contract still passes. contract
PR-03Add an integration test that sends one payment request through the transaction workflow and asserts that exactly one submission reaches the gateway sandbox. integration
PR-04Add an integration test that delays the timestamp step of the transaction workflow and asserts that the payment request does not re-execute. integration
PR-05Add an integration test that retries a payment request with the same idempotency key after a client library exception and asserts that the gateway sandbox records one charge. integration
PR-06Run the Ruby client library's test suite against the platform build that is about to deploy and block the deploy on any parsing exception. integration
PR-07Route traffic from customers on each client library into the canary and compare each library's processing error rate with the baseline. canary
PR-08Halt the rollout when the canary shows more than one gateway submission for any transaction id. canary

First 30 minutes

FM-01Count transactions with more than one gateway submission since the deploy, grouped by client library and gateway.
FM-02Merge duplicate-charge reports arriving through separate support channels into one incident and match their first timestamp to the deploy time.
FM-03Revert the deploy that changed the API response or the transaction workflow if duplicate submissions are still appearing.
FM-04Confirm after the revert that no new transaction id receives a second gateway submission.
FM-05Tell customers not to retry errored transactions until each one is checked against the gateway record.
FM-06Send merchants the list of duplicated transaction ids and the steps to void each duplicate in their gateway portal.
FM-07Post a status update that names the affected client library or gateways and the time window of duplicate submissions.

Download the checklist

Pre-release checklist (Markdown)1.8 KB · v1.0.0
First 30 minutes checklist (Markdown)1.2 KB · v1.0.0

Only in this checklist

PR-01 is the only item among 4 published checklists in this group that relies on contract tests: Register every response field the Ruby client library parses, including eligible_for_card_updater, as a consumer contract and fail the platform build when a deploy removes one.

Questions

What should be checked before a release to prevent Double charge after deploy?

8 pre-release items, PR-01 to PR-08. PR-01: Register every response field the Ruby client library parses, including eligible_for_card_updater, as a consumer contract and fail the platform build when a deploy removes one.

Is there a rollback plan for Double charge after deploy?

The first-30-minutes checklist has 7 items. FM-01: Count transactions with more than one gateway submission since the deploy, grouped by client library and gateway.

What should a team do in the first 30 minutes after Double charge after deploy is detected?

The first-30-minutes checklist has 7 items. FM-01: Count transactions with more than one gateway submission since the deploy, grouped by client library and gateway.

Is a Double charge after deploy checklist still needed if deployment is automated?

Yes. Automation runs the steps; the checklist names what the tests must cover: contract tests, integration tests and canary and progressive delivery checks.

Which pipeline stages does the Double charge after deploy checklist cover?

The pre-release items map to the pre-merge, pre-deploy and post-deploy stages.

In what formats can the Double charge after deploy checklist be downloaded?

Both checklists download as Markdown files: /downloads/double-charge-after-deploy-pre-release.md and /downloads/double-charge-after-deploy-first-30-minutes.md, licensed CC BY 4.0.