Add regional endpoint selection with GatewayArea support

[fern-support]

Add regional endpoint selection with GatewayArea support

Summary

Adds area-based URL selection to the TypeScript SDK, mirroring the pattern implemented in the Go SDK. Users can now specify a gatewayArea (US, EU, APAC, CN) when creating a client to automatically connect to the optimal regional endpoint.

Key changes:

• src/area.ts: Defines GatewayArea type and RegionalEndpointPool class with region cycling support
• src/RegionalClient.ts: Wrapper client that adds gatewayArea and endpointPool options
• src/index.ts: Exports the wrapper as AgoraClient (backwards compatible) plus new GatewayArea and RegionalEndpointPool exports
• .fernignore: Protects manually added files from Fern regeneration

Usage:

import { AgoraClient, GatewayArea } from "agora-sdk";

const client = new AgoraClient({
    gatewayArea: GatewayArea.US,
    username: "...",
    password: "...",
});

Note: Unlike the Go SDK, DNS-based domain selection is intentionally omitted for browser compatibility. The TS SDK uses a fixed priority order instead.

Updates since last revision

• Fixed regional URL path: Added /api/conversational-ai-agent suffix to getCurrentUrl() to match the default environment URL structure
• Fixed TypeScript type error: Refactored RegionalClient.ts constructor to capture endpointPool in a narrowed const pool variable, ensuring the baseUrl supplier returns string instead of string | undefined
• Merged main with pagination type fix: Incorporated the SDK regeneration from fern-config PR#1 which fixed the Cannot find namespace 'undefined' build errors
• Fixed pre-existing test bug: Updated agents.test.ts to use a non-empty cursor value for pagination test (empty cursor "" correctly returns hasNextPage() = false, matching the telephony test pattern)

Review & Testing Checklist for Human

• Verify region configuration matches Go SDK: Compare REGION_DOMAIN_CONFIG in area.ts against the Go SDK's RegionDomain map to ensure prefixes and suffixes are identical
• Test backwards compatibility: Existing code using AgoraClient without gatewayArea should continue to work unchanged
• Test regional endpoint selection: Create a client with gatewayArea: GatewayArea.US and verify requests go to https://api-us-west-1.agora.io/api/conversational-ai-agent
• Verify baseUrl supplier logic: In RegionalClient.ts, confirm the const pool = endpointPool narrowing correctly captures the pool before creating the supplier function

Recommended test plan:

1. Install the SDK locally and create a client without gatewayArea - verify it uses the default environment
2. Create a client with each GatewayArea value and log/inspect the base URL being used
3. Test nextRegion() cycling behavior on the endpoint pool

Notes

• Companion PR for Python SDK: Add regional endpoint selection with GatewayArea support agora-agents-python#1
• Fern config fix for pagination types: https://github.com/fern-demo/agoraio-fern-config/pull/1

Link to Devin run: https://app.devin.ai/sessions/3f033f4523f94c2384477ddfc79d00a8
Requested by: blank@buildwithfern.com (@fern-support)

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

⚙️ Control Options:

• Disable automatic comment and CI monitoring

[digitallysavvy]

@fern-support is this still needed?