Add MCP codex-reply Support for Resuming Conversations from Rollout Files

[nikhil-pandey]

What feature would you like to see?

I’d like to resume an existing Codex conversation via the MCP interface the same way the CLI already allows with codex resume <sessionId>.

Today the codex-reply MCP tool only succeeds if the conversation is still resident in the server’s in-memory ConversationManager. If the CLI has exited
—or if I start a fresh npx codex mcp-server—that map is empty, so codex-reply immediately returns:

Session not found for conversation_id:

The rollout JSONL file is present on disk (e.g. ~/.codex/sessions/2025/11/03/rollout-...-019a4af1-f34f-7380-9133-6d1479737864.jsonl), and the CLI is able to hydrate it with codex resume 019a4af1-f34f-7380-9133-6d1479737864. The MCP server never exposes that resume path, so there’s no way for external integrations to continue a halted session.

Additional information

No response

[github-actions]

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

• feat: MCP tool enable to resume conversations from persistence #5066
• Codex MCP tool responses omit conversation metadata, blocking codex-reply #5660
• codex mcp no return conversationId or codex-reply conversationId no required #4651

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[ClaytonSmith]

+1 to this.