Disable MCP elicitation in headless runs #36076

Problem

Headless OpenCode runs (opencode run, GitHub Actions, and other non-interactive/CI contexts) should not expose interactive elicitation paths to the model or to MCP servers.

Today MCP elicitation can require a human response. In a headless run there is no usable UI to answer it, so it can block, hang, or produce unusable behavior. This is the same class of problem as the existing question-tool behavior tracked in #10012.

Desired behavior

When OpenCode is running headlessly/non-interactively:

• Opt out of MCP elicitation by default.
• Do not advertise/support elicitation capabilities to MCP servers in that mode, or reject elicitation requests immediately with a clear non-interactive error.
• Apply the same policy direction to the built-in question tool: interactive asks should not be available in opencode run/CI unless explicitly opted in through a deliberate escape hatch.

Acceptance criteria

• opencode run does not hang waiting for MCP elicitation or question responses.
• GitHub Action usage gets deterministic failure/skip behavior rather than an unresolved prompt.
• Interactive clients keep their current elicitation/question behavior.
• Tests cover at least one headless path and one interactive path.

Related

• Question tool error, ' stops/hangs execution completely in headless mode #10012 tracks the question tool hanging/erroring in headless CLI usage.

Requested by @rekram1-node from team discussion on 2026-07-09.