v9.1

Release Notes – Massive JS Client v9.1 (breaking changes)

This is a major breaking release of the JS client as part of our company rebrand from Polygon.io to Massive.com. Polygon.io has rebranded as Massive.com effective October 30, 2025. Existing API keys, accounts, and integrations continue to work exactly as before. The only change in this SDK is that it now defaults to the new API base at api.massive.com, while api.polygon.io remains supported for an extended period.

Breaking Changes

• The default REST API base URL has changed from api.polygon.io → api.massive.com.
• The default WebSocket base URL has changed from socket.polygon.io → socket.massive.com.
• The package name and import path have changed from polygon → massive.

No other breaking changes are introduced. Core functionality, endpoints, and method signatures remain identical.

Migration Guide

To upgrade:

npm install --save '@massive.com/client-js'

Then update your imports:

import { restClient } from '@polygon.io/client-js'; # Old
import { restClient } from '@massive.com/client-js'; # New

All API keys, accounts, and integrations continue to function without modification. If you continue using the legacy polygon-api-client package, it will remain supported for an extended transition period.

ℹ️ Additional Information

• No changes to client methods, models, or response structures.
• Both API domains (polygon.io and massive.com) are fully operational in parallel.
• For full background, see our blog post: Polygon.io is Now Massive.
• For help, open an issue or contact support@massive.com.

What's Changed

• Rebrand client to massive.com by @justinpolygon in #246
• [DVX-1121] add interface for stocks > noi response by @penelopus in #248
• [DVX-1134] Updated with latest 2025-11-19 spec by @justinpolygon in #249

Full Changelog: v8.2.0...v9.1