Permissions

What permissions control

Permissions determine how often Happier asks for approval when an agent wants to run tools (like editing files or running commands), and how restrictive the session environment should be.

You can set permissions in two places:

• CLI: when starting a session
• App UI: per-session (and as defaults for new sessions)

Happier stores your choice in the session so it stays consistent when you open the same session on another device.

Permission modes

These are the modes you may see in the CLI and/or the app:

• Default: uses the provider’s normal behavior (ask when needed).
• Read-only: the agent can read and inspect, but write-like actions are denied.
• Safe YOLO: automatically allows read-like actions; asks for approval before write-like actions.
• YOLO: skips approvals as much as the provider allows (full speed, least safe).

Not every provider supports every mode. When a mode isn’t supported, Happier will fall back to the closest supported behavior and show you the Effective policy in the UI.

Session modes (ACP)

Some ACP-based providers expose session modes (for example, “plan” vs “build”).

Session modes are separate from permissions:

• Permissions control approvals and safety boundaries.
• Session modes control the agent’s operating mode (provider-defined).

CLI usage

Start a session with an ACP session mode:

happier opencode --agent-mode plan
happier kilo --agent-mode plan

App UI usage

In a session, open the input settings and pick a value from the Mode section when it’s available for the current provider.

Note: Claude’s Plan is a provider-native permission mode, so it appears under Permissions (not under Mode).

Resume support (ACP)

Some ACP providers support resuming an existing vendor session via ACP’s loadSession.

As of this release, Happier treats loadSession support as capability-driven:

• Supported (in principle): OpenCode, Gemini, Auggie, Qwen, Kimi, Kilo
• Codex ACP: varies by build; Happier probes support and will fail closed (it won’t silently start a fresh session when resume is unavailable).

Model selection

Some providers let you choose which model runs your session.

If model selection is available, you can set it from:

• CLI: when starting the session
• App UI: from the input settings inside a session

CLI usage

happier gemini --model gemini-2.5-pro

App UI usage

In a session, open the input settings and pick a model from the Model section.

For ACP providers that advertise supported models, Happier will show the provider’s live list. For providers without a live list (like Claude Code), Happier may allow entering a custom model id.

Model apply behavior (what happens after you change it)

Model changes are capability-driven and provider-specific:

• Claude: applies on the next prompt (no session restart required).
• Codex (MCP): model is decided when the MCP session starts; changing model means starting a new MCP session.
• Codex/OpenCode/Kilo/Auggie (ACP): Happier applies model changes live when session/set_model is supported; otherwise it falls back to provider config options when available.
• Gemini (ACP): model changes may require recreating the underlying ACP process; Happier preserves context using replay/history so the session still continues.

CLI usage

Start a session with a permission mode:

happier codex --permission-mode read-only
happier codex --permission-mode safe-yolo
happier claude --permission-mode yolo

Aliases (you can use the words you already know)

The CLI accepts common aliases and normalizes them automatically:

• readonly, read only, ro → read-only
• full, full-access, danger-full-access, bypass → yolo
• ask, prompt, auto → default
• accept-edits (Claude wording) → safe-yolo
• bypass-permissions (legacy) → yolo

If you pass an unknown value, Happier prints the supported list and examples.

App UI usage

Change permissions for the current session

In a session, open the permission chip (shield) and pick a mode.

The picker shows:

• a short description of each mode, and
• an Effective line that explains what the selected mode means for the current provider/session.

Set defaults for new sessions

Go to Settings → Session and set your default permission mode per provider.

When does a change apply?

In Settings → Session, you can control when a permission change takes effect:

• Immediate: publish the new permission mode to the session right away (best when you want the running agent to react without sending a new message).
• Next prompt: apply the new mode to the next message you send, and publish it after that message is committed (best when you want the change to “arm” for the next request without touching the current running turn).

If you select Next prompt and then don’t send a message, the change stays local to your device until you send one.

Provider notes (what to expect)

Codex (MCP vs ACP)

Codex can run via different backends:

• ACP: exposes provider-native policy presets (approval + sandbox combinations). These are not generic “plan/build” agent modes.
• MCP: tool approvals can update mid-session, but some environment/sandbox controls may only apply when starting a new session.

In Happier, permissions remain the primary control for Codex. Happier maps your selected permission intent to the closest Codex ACP policy preset when available.

Model IDs can also vary by Codex build and account. If model selection isn’t shown in the app for your Codex session, you can still set it via the CLI (when supported by your installed Codex backend).

The UI’s Effective line is the source of truth for what your current session will do.

Claude

Claude supports additional provider-native modes (like Plan) and edit-oriented flows (like Accept Edits).

If you choose a mode that Claude doesn’t support directly (for example Read-only), Happier will fall back and show the mapping in the Effective line.

Examples:

• Read-only → Effective: View-only
• Accept Edits can map to a provider-supported edit/approve flow depending on your Claude backend and version

If the Effective mode is different from what you expected, treat the Effective line as source of truth for that session.