OpenAI adds Developer mode to ChatGPT with full MCP client support

OpenAI’s Developer mode is now available to Pro and Plus subscribers on the web. Once enabled through the Connectors menu in settings, it provides a dedicated interface for connecting to remote MCP servers. Supported protocols include server-sent events and streaming HTTP, with OAuth or no authentication available.

Users can add, toggle, and refresh tools exposed by MCP servers directly inside ChatGPT. During conversations, Developer mode appears as an option in the Plus menu. To ensure correct tool usage, users are advised to issue explicit instructions, disallow alternatives, and disambiguate overlapping tool names. OpenAI recommends structuring prompts to specify input formats and call order, particularly when chaining read and write operations.

Write actions require explicit confirmation before execution. ChatGPT displays the full JSON payload of each tool call, allowing users to review parameters and outputs before approval. The system recognizes the readOnlyHint annotation to distinguish safe read operations from potentially destructive actions. Users can choose to remember tool approvals within a single conversation, though new or refreshed chats reset confirmation requirements.

By exposing the full MCP interface, Developer mode allows ChatGPT to act as a client for enterprise systems, CRMs, code repositories, and other external applications. This expands the platform’s role in workflow automation but also raises safety concerns. OpenAI cautions developers to monitor for prompt injection risks, incorrect tool behavior, and malicious connectors.