Guidelines for hosts to support Command Line (CLI) MCP Apps

Assessment

This issue has not been assessed yet.

Description

Motivation

• A MCP app will work out of the box in many browser-based hosts (Claude, ChatGPT, Goose, Cursor), but in very few command-line hosts (Pi MCP Adapter) is the only general purpose one I've seen) . Many dev working primarily in the CLI, so we end up having to write custom integrations for each CLI host.
• For Datadog's [MCP apps](https://www.datadoghq.com/blog/datadog-mcp-apps/, we had to ship a separate UI host in Claude Code launched via session hook. Due to the nature of the hooks API, communication is one-way, so apis like callServerTool do not work. Codex faces similar challenges.

Proposal

We could provide guidelines for how CLIs (Claude Code, Codex, Goose, Antigravity, etc) could support MCP app so MCP apps written for the desktop/web/mobile hosts can be used by devs without requiring MCPs to be used alongside custom hook/script combos to ship custom host-specific glue code. .

Alternatives

Users adopt CLI tools that offer a plugins API which allows for bidirectional communication and/or native MCP apps integration, like OpenCode and Pi . (Note OpenCode doesn't support it natively https://github.com/anomalyco/opencode/issues/14663 , though the plugin system probably allows for it)

Additional Context

Here's a GIF of an MCP app working with Claude Code CLI using a custom glue program. Ideally we could remove the glue program, and rely on a host that ships with Claude Code itself.

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