API version dropped while old app live: symptoms, cause, and the test that catches it

The backend removes an API version still used by installed app versions.

API version dropped while old app live is documented by 2 accepted public reports from 2 organisations, 1 of them published in the last 5 years.

Likelihood: not published (1 public report in 5 years)
Impact: medium (2 of 2 reports: availability)

2 public reports · verified 2026-10-21

Symptoms

User-visible

Tools and integrations that called the admin API with dated versions such as 2023-01-01 and 2023-02-01 failed.[1]
Workflows run through an infrastructure-as-code provider plugin, the vendor's command-line tool and custom automation returned automation errors.[1]
Old versions of a release upload command-line tool and other clients that called the release upload APIs had issues after the deprecation.[2]

Monitoring-visible

API calls returned HTTP 410 responses stating that the requested API version was no longer available.[1]
Support tickets from customers running old command-line versions arrived after the release upload APIs were deprecated.[2]

Root causes

stage: config A planned retirement process for older admin API versions took effect while installed tools and integrations still pinned those versions.[1]
stage: release-process The release upload APIs were deprecated because they relied on backend services of a predecessor product that was shut down. Old command-line versions and other clients still called those APIs.[2]
stage: release-process A retirement keyed only to a date, with no check of live request counts per API version, can switch off a version that installed clients still call. by design analysis

Public examples

[1]MongoDB, 2026-03-02. MongoDB's planned retirement of older versions of its cloud database Admin API made installed tools still pinned to those versions, including the Terraform provider and the vendor command-line tool, fail with HTTP 410 for about 36 hours until the end-of-life date was extended through a configuration change. primary MongoDB Atlas Admin API: Temporary failures for tools using older API versions
[2]App Center, 2020-12-09. App Center deprecated its Release Upload APIs as part of the HockeyApp shutdown, which broke old versions of the App Center CLI and other clients that still called those APIs, and the team temporarily restored the old APIs until 1 February 2021. primary Temporarily Restoring Old Versions of App Center CLI and Release Upload APIs

Test classes that catch it

Test class	Stage	Limitation	Basis
Contract tests	pre-deploy	A contract suite covers only the client versions registered in it, so a pinned infrastructure-as-code plugin or a customer's own automation that never published a contract still fails when its API version is retired.	by design analysis
Configuration and environment tests	pre-deploy	A configuration check confirms the end-of-life date value and its rollback path, but it has no view of which installed clients still send the retired version.	by design analysis
Synthetic monitoring	post-deploy	A scheduled probe that calls only the current API version stays green, because only old client versions received the HTTP 410 response.	by design analysis

Risk

Likelihood: not published (1 public report in 5 years)
Impact: medium (2 of 2 reports: availability)

Counts behind the grades
Accepted public reports	2
Published in the last 5 years	1
Impact stated: availability	2

How the grades are computed

Pre-release checklist

PR-01Keep one contract test per client version still in distribution, including each old command-line release, and run all of them against the API before a version retirement takes effect. contract
PR-02Run the contract suite of every client pinned to the API version being retired against a staging environment with the retirement switched on, and block the retirement if any contract fails. contract
PR-03Add a contract test that pins the response a retired API version returns, so old clients receive a version-retired message and a minimum client version. contract
PR-04Query request logs for calls per API version before the end-of-life date and block the retirement config change while the retired version still receives requests. config
PR-05Confirm the end-of-life date for each API version is a configuration value that can be moved to a later date without a deploy. config
PR-06Schedule a production probe that calls the API with each oldest still-supported version and alerts on any HTTP 410 response. synthetic
PR-07Schedule a production check that runs the oldest still-distributed upload command-line version against the release upload endpoint and alerts on failure. synthetic

First 30 minutes

FM-01Group new errors and support tickets by client version and API version to confirm the failures come from old pinned versions.
FM-02Check whether a scheduled API version retirement or deprecation took effect at the start time, with no application deploy.
FM-03Search API logs for HTTP 410 responses stating that the requested API version is no longer available.
FM-04Decide whether to extend the end-of-life date through a configuration change or to restore the old endpoints temporarily.
FM-05Tell customers that failed operations can be retried once compatibility is restored.
FM-06Post a status update that names the affected API versions, the affected client versions and the new cut-off date.
FM-07Publish the minimum client versions customers must upgrade to before the new cut-off date.

Download the checklist

Pre-release checklist (Markdown)1.7 KB · v1.0.0
First 30 minutes checklist (Markdown)1.1 KB · v1.0.0

What catches this: catalogue entries

Listed because their own documentation or site names contract tests, configuration and environment tests, synthetic monitoring on the verification date. Alphabetical. Not a recommendation.

Tools whose documentation names these test classes

Checkly synthetic source verified 2026-10-21
Datadog Synthetic Monitoring synthetic source verified 2026-10-21
Flipt config source verified 2026-10-21
Grafana Cloud Synthetic Monitoring synthetic source verified 2026-10-21
Grafana k6 synthetic source verified 2026-10-21
GrowthBook config source verified 2026-10-21
LaunchDarkly config source verified 2026-10-21
Pact contract source verified 2026-10-21
PostHog config source verified 2026-10-21
Postman synthetic source verified 2026-10-21
Schemathesis contract source verified 2026-10-21
Specmatic contract source verified 2026-10-21
Unleash config source verified 2026-10-21
Uptime Kuma synthetic source verified 2026-10-21

Providers whose site names these test classes

Full Scale contract source verified 2026-10-21
QA Madness contract source verified 2026-10-21
QASource contract source verified 2026-10-21
Quality Island contract source verified 2026-10-21

Only on this page

API version dropped while old app live starts in config in report [1] and in the release process in report [2]. In report [1] and report [2], no new client build carried the fault. The trigger was a server-side retirement of an API that installed tools still called.

In report [1], the planned retirement of older admin API versions returned HTTP 410 to pinned tools for about 36 hours. The fix was a configuration change that extended the end-of-life date to a tentative 2027-07-01 [1]. In report [2], the release upload APIs were restored temporarily until 1 February 2021, after customer feedback and support tickets. The guard for this incident sits on the retirement switch itself, not on the client release pipeline.

Deep link broken after routing change Deep links or universal links open the wrong screen or nothing.
In-app purchase receipt validation fails Store receipts are rejected after a validation or sandbox endpoint change.
Schema drift between services Two services expect different versions of a shared schema after one is deployed without the other.
API key rotation breaks integrations A key rotation invalidates partner integrations that were not notified.
Asset cache serves old bundle Users receive an old JavaScript bundle with a new API and the app errors.

Questions

What causes API version dropped while old app live?

In report [1], a planned retirement of older admin API versions took effect while installed tools still pinned them. In report [2], release upload APIs were deprecated when the backend services they relied on were shut down.

What are the symptoms of API version dropped while old app live?

Pinned tools received HTTP 410 responses stating that the requested API version was no longer available [1]. Old command-line versions that called the release upload APIs had issues, and customers filed support tickets [2].

Which test class catches API version dropped while old app live, and what does it miss?

Contract tests, configuration tests and synthetic monitoring carry the by-design label, because neither report names a test class. A contract suite misses client versions that never published a contract, such as a customer's own automation.

Which public reports document API version dropped while old app live?

Two primary reports document it, published on 2026-03-02 [1] and 2020-12-09 [2]. Both classify the impact as availability.

How long did it take to detect API version dropped while old app live in the public reports?

Neither report states a time to detect. Report [2] names customer feedback and support tickets as the detection path.

Should a team roll back or fix forward when API version dropped while old app live happens?

Both reports rolled the retirement back: report [1] extended the end-of-life date through a configuration change, and report [2] restored the old APIs until 1 February 2021. FM-04 covers this decision.

Release Incident Playbook (2026). API version dropped while old app live: symptoms, cause, and the test that catches it, content version 1.0.0. https://releasefailures.com/incidents/api-version-dropped-while-old-app-live/. Accessed 2026-10-21.