# Does This Release Affect Your Code? Check the Behavior Before You Upgrade

Imagine your authentication SDK announces a change to sign-in redirects. Your product uses the SDK and has a callback route. You could hand the release note to your coding agent with “upgrade this and fix anything that breaks.”

But you have not yet established what needs fixing.

Two products can use the same SDK and need different responses to the same release. One supplies an explicit destination after every sign-in. The other relies on the SDK’s default. If the release changes only that default, the second product has something to investigate; the first may have no work to do for this particular change.

That is the useful question before an upgrade: **where does your product depend on the behavior that changed?**

The redirect example is hypothetical, building on [ShipFoundry’s fictional sample investigation](https://shipfoundry.ai/docs/sample-investigation-brief). It illustrates a decision you can make with your own release note and repository, without assuming every update deserves a migration.

## Find the condition that makes the release matter

A headline such as “improved authentication” gives you little to inspect. “Sign-in uses a different default destination when no redirect is supplied” gives you a condition to look for: calls that omit a destination.

Read the actual release source for what changes, which versions or configurations it affects, and when it takes effect. Then turn it into a question about your product:

> Do any of our sign-in paths rely on the SDK’s default redirect destination?

The same move works beyond authentication. A faster compiler matters if the operation it improves contributes meaningfully to your build time. A retiring API matters if your service still calls the affected endpoint. Each question points toward evidence that can change your decision.

Keep the scope specific. Finding that one redirect change does not apply says nothing about the rest of the release.

## Trace the dependency to the user’s experience

First establish what you are inspecting. Record the repository revision and check the relevant application’s resolved SDK version in its lockfile. A package manifest may specify a range; it does not by itself establish the resolved version. If the decision concerns production, confirm which revision is deployed, too.

Then follow the changed behavior through the code:

```text
Resolved SDK version
  → authentication wrapper
  → sign-in calls
  → callback route
  → destination the user reaches
```

Search for the package, changed method or option, then read the surrounding code. When you find a wrapper, follow its callers. The routes that depend on the SDK may never mention its name.

In our hypothetical example, suppose every relevant sign-in call supplies an explicit destination and the release leaves explicit destinations unchanged. That supports no action for the default change within the inspected scope.

Now suppose a sign-in path omits the destination. You have found possible exposure. Compare the old and new defaults with what your product requires: does the user still reach the page they intended to visit, or end up somewhere else?

The package match was identical. The behavior changed the decision.

Be careful with negative findings. A search that finds no calls can miss aliases, generated clients or another library’s wrapper. Provider settings may also live outside the repository, and remote APIs can change without a package upgrade. Name a gap when it could alter the conclusion:

> The inspected sign-in paths supply explicit destinations. Provider configuration was not checked.

That gives the next person a usable boundary around the finding.

## Check the consequence, not just the build

A relevant call tells you where to look. It does not demonstrate that an upgrade works.

For a redirect change, the consequence is where the user lands after authentication. A successful build cannot establish that. Read the existing tests: do they check the destination, or merely confirm that a sign-in function was called? Does the callback run, or does a mock supply the expected result?

Choose checks that would expose the changed behavior. In this example, test sign-in with an explicit destination and with no destination, plus any return-path or failure behavior your product supports. Establish the current behavior first, then run the same checks against a proposed upgrade in an authorized test environment.

If the provider-backed flow cannot run, preserve that distinction in the result: “Local checks passed; the provider callback was not exercised.” The missing check may be the one that determines whether the migration is safe to ship.

## Give your agent the question you have not answered

You can delegate the investigation before you know whether a patch is needed. The task should make that uncertainty clear.

Attach the actual release link and use a handoff like this:

```markdown
Investigate whether the documented default redirect change affects sign-in.

Confirm the repository revision and resolved SDK version.
Trace sign-in calls, wrappers and callback handling.
Find calls that omit an explicit destination.
Compare their behavior with the release's affected conditions.
Inspect relevant tests and run them where the environment permits.

Investigation only. Do not edit code or provider settings.

Return:

- Whether the change applies, with file and symbol references.
- Tests run, results and checks not run.
- Any missing evidence that could change the conclusion.
- A recommended next action and how to verify it.
```

This is the distinction in [ShipFoundry’s brief documentation](https://shipfoundry.ai/docs/investigation-briefs): an Engineering Spike resolves whether and how to act; a Hand To Agent brief describes a specific implementation supported by evidence. Once the investigation justifies a change, give that implementation a bounded scope and acceptance checks.

## Finish with a decision someone can revisit

Applicability and priority are separate judgments. An optional improvement may affect your code but offer little value this week. An endpoint retirement may demand action because continued operation has a deadline.

Close the investigation with one of four outcomes:

- **Act:** identify the change, expected result and verification needed.
- **Investigate:** name the consequential question and the evidence needed to answer it.
- **Defer:** record why the work can wait and what would trigger another look.
- **No action:** record why the changed behavior does not apply, including the inspected scope.

Include the repository revision. “No action for this default redirect change at this commit” remains useful when someone later adds a sign-in path that relies on the default.

For recurring release triage, [ShipFoundry’s documented workflow](https://shipfoundry.ai/docs/quickstart) connects a read-only GitHub repository and uses source evidence, repository findings and briefs to guide the next task. Its [readiness guidance](https://shipfoundry.ai/docs/trust-and-readiness) makes the same distinction: strong code evidence supports relevance; tests and review still establish whether a proposed change works.

Before assigning your next upgrade, ask whether you can complete this sentence:

> At this revision, this release affects this behavior because of this code, and our next step is this.

If you cannot, give your agent the missing question. If the evidence supports no action, record why and get back to building.