Direct answer
Verify an API migration by running agreed customer workflows against the target provider version in the configurations that matter. Record the code version, provider version, scenario, result, and limit beside each check. Old responses, a green build, or one happy path cannot establish compatibility across untested permissions, mappings, retries, and partial failures.
The new endpoint works in a demo account. A limited-permission tenant returns no records.
An application moves a CRM import to a new API version. The standard test account returns a complete contact list. A tenant with a limited permission set receives an empty page rather than an error, and the workflow incorrectly reports a completed import.
Check whether the agreed import behavior holds under the target version for each configuration in scope. Record which checks use a real provider account and which rely on simulated behavior.
Separate build results, provider checks and coverage.
Does the code compile and run?
Useful evidence about the application package. It does not exercise a changed provider response.
Does the workflow behave as agreed?
Exercises the target behavior in a provider account or a simulator with stated fidelity evidence. Record which one was used.
What does the result exclude?
Makes untested permissions, configurations, environments, and failure paths visible.
Set up checks that can contradict the patch.
- 01
Pin the versions
Record the application revision, provider or SDK version, and any relevant configuration revision.
- 02
Write the scenario
Name the workflow input, expected customer result, and prohibited effects such as a duplicate write.
- 03
Choose the sample
Select configurations that materially change permissions, mappings, or workflow branches. Include request concurrency and deadlines when they affect the required behavior.
- 04
Exercise failure paths
Include relevant pagination, retries, partial responses, rate limits, or recovery behavior.
- 05
Record the limit
Keep missing environments and untested configurations beside the result rather than implying complete coverage.
What a migration check should record.
- Application revision and target provider or SDK version
- The named workflow and observable customer result
- Input data, permissions, configuration, and environment
- Expected outputs and prohibited effects
- Relevant retries, timeouts, partial failures, or rate limits
- Pass, fail, or unavailable evidence with a reason
- Untested configurations and the owner of the next check
A migration result with a visible limit.
Illustrative example, not customer results
- Application revision
- contact-import 8f3c2a1
- Target provider
- CRM API v4
- Scenario
- Import two paginated pages with limited permissions
- Required behavior
- Each permitted contact arrives once
- Observed result
- Pass: two pages imported, no duplicate writes
- Not covered
- Custom field mapping environment unavailable
- Customer action
- Review patch and decide whether to release
When your current tools are enough
You may not need Telryn if your current integration test suite already runs the target provider behavior across the configurations that matter, records exclusions, and gives the release owner enough evidence to act.
Add a second testing layer only where the current process leaves a meaningful workflow or configuration untested.
Telryn early access
Need to check a migration beyond the happy path?
Tell us which provider and configuration your existing test environment cannot exercise reliably. Your engineers would own the application fix and release. This is early-access discovery, not a migration-service offer.
In development. No product access yet.
Sources and limits
- Nango: Custom integration serviceNango describes integration implementation, target-account testing, validation, and maintenance as APIs change. Accessed 2026-09-09.
- WireMock: Agent skills for WireMock CloudStateful API simulation is one available way to exercise integration behavior. Accessed 2026-09-09.
The scenario is hypothetical. Passing an agreed scenario is bounded evidence, not proof that every customer configuration will work.