VAPI-3164 Add <Refer> BXML verb support

[nkuma246]

This pull request adds support for the <Refer> BXML verb, which allows initiating a SIP REFER on an existing call to redirect the remote SIP endpoint to a third party. The changes include the implementation of the Refer verb, updates to documentation, and unit tests to ensure correct behavior.

New Feature: Refer BXML Verb

• Added the Refer class to represent the <Refer> BXML verb, including all relevant attributes such as sipUri, referCompleteUrl, and authentication fields.
• Registered the Refer verb in the Bxml class so it can be included in BXML documents.

Documentation Updates

• Added docs/Refer.md with a detailed explanation of the <Refer> verb, its properties, and usage.
• Updated the README.md to include a reference to the new <Refer> verb documentation.

Testing

• Added unit tests in ReferVerbTest.java to verify XML serialization for both minimal and full attribute cases of the <Refer> verb.

[bwappsec]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues
✅	Code Security	0	0	0	0	0 issues

💻 Catch issues earlier using the plugins for VS Code, JetBrains IDEs, Visual Studio, and Eclipse.

[Copilot]

Pull request overview

Adds SDK support for the new <Refer> BXML verb and introduces a corresponding ReferCompleteCallback model in the generated OpenAPI surface, along with documentation and unit tests.

Changes:

• Added Refer verb model, registered it in Bxml, and added JAXB serialization unit tests.
• Added ReferCompleteCallback model + docs, and registered its Gson type adapter.
• Updated shared callback eventType documentation across multiple generated callback models/docs/specs to include referComplete.

Reviewed changes

Copilot reviewed 53 out of 53 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/test/java/com/bandwidth/sdk/unit/models/bxml/ReferVerbTest.java	Adds JAXB serialization tests for <Refer> verb output.
src/main/java/com/bandwidth/sdk/model/TransferDisconnectCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/TransferCompleteCallback.java	Updates generated model docs (currently describing Refer Complete).
src/main/java/com/bandwidth/sdk/model/TransferAnswerCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/TranscriptionAvailableCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/ReferCompleteCallback.java	Adds new generated callback model for Refer Complete events.
src/main/java/com/bandwidth/sdk/model/RedirectCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/RecordingCompleteCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/RecordingAvailableCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/MachineDetectionCompleteCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/InitiateCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/GatherCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/DtmfCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/DisconnectCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/ConferenceRedirectCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/ConferenceRecordingAvailableCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/ConferenceMemberJoinCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/ConferenceMemberExitCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/ConferenceCreatedCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/ConferenceCompletedCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/bxml/Refer.java	Adds the <Refer> BXML verb model and its attributes.
src/main/java/com/bandwidth/sdk/model/bxml/Bxml.java	Registers <Refer> as a supported verb within <Bxml>.
src/main/java/com/bandwidth/sdk/model/BridgeTargetCompleteCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/BridgeCompleteCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/model/AnswerCallback.java	Updates eventType doc list to include referComplete.
src/main/java/com/bandwidth/sdk/JSON.java	Registers Gson adapter factory for ReferCompleteCallback.
README.md	Adds model doc link for ReferCompleteCallback.
docs/TransferDisconnectCallback.md	Updates eventType doc list to include referComplete.
docs/TransferCompleteCallback.md	Updates generated markdown model doc (currently describing Refer Complete).
docs/TransferAnswerCallback.md	Updates eventType doc list to include referComplete.
docs/TranscriptionAvailableCallback.md	Updates eventType doc list to include referComplete.
docs/ReferCompleteCallback.md	Adds markdown documentation for ReferCompleteCallback.
docs/Refer.md	Adds documentation page for the <Refer> BXML verb.
docs/RedirectCallback.md	Updates eventType doc list to include referComplete.
docs/RecordingCompleteCallback.md	Updates eventType doc list to include referComplete.
docs/RecordingAvailableCallback.md	Updates eventType doc list to include referComplete.
docs/MachineDetectionCompleteCallback.md	Updates eventType doc list to include referComplete.
docs/InitiateCallback.md	Updates eventType doc list to include referComplete.
docs/GatherCallback.md	Updates eventType doc list to include referComplete.
docs/DtmfCallback.md	Updates eventType doc list to include referComplete.
docs/DisconnectCallback.md	Updates eventType doc list to include referComplete.
docs/ConferenceRedirectCallback.md	Updates eventType doc list to include referComplete.
docs/ConferenceRecordingAvailableCallback.md	Updates eventType doc list to include referComplete.
docs/ConferenceMemberJoinCallback.md	Updates eventType doc list to include referComplete.
docs/ConferenceMemberExitCallback.md	Updates eventType doc list to include referComplete.
docs/ConferenceCreatedCallback.md	Updates eventType doc list to include referComplete.
docs/ConferenceCompletedCallback.md	Updates eventType doc list to include referComplete.
docs/BridgeTargetCompleteCallback.md	Updates eventType doc list to include referComplete.
docs/BridgeCompleteCallback.md	Updates eventType doc list to include referComplete.
docs/AnswerCallback.md	Updates eventType doc list to include referComplete.
bandwidth.yml	Adds referCompleteCallback schema and updates eventType list; updates transferCompleteCallback description text.
api/openapi.yaml	Adds referCompleteCallback schema and updates eventType list; updates transferCompleteCallback description text.
.openapi-generator/FILES	Includes newly generated model/doc files in generator manifest.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[stampercasey]

Review from Claude Code — see inline comments for individual findings. Four blockers, all in the verb attributes and callback model.