Add non-interactive exec and input prompt support

[flynnhandley]

Describe the feature or problem you'd like to solve

No response

Proposed solution

Benefits

• Enables scripting, automation, and CI use cases.

Proposed Solution

Add a new subcommand:

copilot exec [OPTIONS] [PROMPT]

• PROMPT: natural language instructions. If - or omitted, read from stdin.
• Options: --model, --sandbox, --full-auto, --dangerously-bypass-approvals, --json, --output-schema, --resume, etc. (aligning closely with Codex CLI).
• Default: propose a command and ask for approval.
• --full-auto: run automatically in a safe sandbox.
• --json: emit JSONL output for scripting and pipelines.

Example prompts or workflows

• Log parsing
  cat app.log | copilot exec "print only lines with status 500 and count them"

• Scaffold a project
  copilot exec "init a Node project, install express, add GET /health route"

• jq help
  curl -s https://api.example.com/items | copilot exec - "write a jq command to list id and name"

• Safe repo search
  copilot exec "grep for TODOs excluding node_modules"

• Python quick test
  copilot exec "create venv, install requests, fetch https://example.com"

Additional context

Problem

Copilot CLI currently only works in interactive mode.

There’s no way to:

• Run a one-off prompt non-interactively.
• Pipe stdin into the agent and get a command back.
• Use Copilot CLI inside scripts, CI/CD, or makefiles.

Codex CLI provided this via codex exec. Users migrating from Codex expect similar functionality.

[lostintangent]

If you run copilot -p <prompt>, that allows you to run prompts headlessly (vs. with the TUI). If you get a chance to check it out, I'd love to hear how well that suits your use cases, since we definitely want it to be well-suited for automation/scripting 👍

[flynnhandley]

If you run copilot -p <prompt>, that allows you to run prompts headlessly (vs. with the TUI). If you get a chance to check it out, I'd love to hear how well that suits your use cases, since we definitely want it to be well-suited for automation/scripting 👍

Excellent, that works for me!

I assumed this feature isn't available, because running copilot "do something" returned:
error: too many arguments. Expected 0 arguments but got 1.

Perhaps the error message could reference copilot --help?

[avanderhoorn]

If you run copilot -p <prompt>, that allows you to run prompts headlessly (vs. with the TUI). If you get a chance to check it out, I'd love to hear how well that suits your use cases, since we definitely want it to be well-suited for automation/scripting 👍

Excellent, that works for me!

I assumed this feature isn't available, because running copilot "do something" returned: error: too many arguments. Expected 0 arguments but got 1.

Perhaps the error message could reference copilot --help?

@flynnhandley Addressed in daily!

[RyanHecht]

The error messages are improved in
https://github.com/github/copilot-cli/releases/tag/v0.0.329