Browserbase
Stagehand
Stagehand consolidated session management and broadened LLM provider support while decoupling its CLI tooling from core releases. The SDK added HTTP header control via page.setExtraHTTPHeaders() and context.setExtraHTTPHeaders(), plus cookie management APIs (addCookies(), clearCookies(), cookies()). The browse CLI graduated to its own release cycle with context persistence flags (--context-id, --persist) and connection recovery for broken browser sessions. Server-side work unified selector types across v4 routes, added Vertex and Bedrock provider support, and fixed schema parsing for Pydantic models and agent initialization race conditions with script injection.
Stagehand focused on expanding browser connectivity and header management throughout March. The SDK added cdpHeaders for custom HTTP headers when connecting to existing browsers via CDP, and new page.setExtraHTTPHeaders() and context.setExtraHTTPHeaders() methods for request customization. The browse CLI graduated from initial release with context persistence support via --context-id and --persist flags, decoupled its release cycle from core, and added a --connect flag for reusing existing Browserbase sessions. Server releases fixed schema parsing for Pydantic models, resolved state caching issues when browser connections drop, and removed support for retired Claude model versions.