Agent Desktop

agent-desktop

agent-desktop is a CLI that reads and operates desktop apps through the OS accessibility tree. Every command prints one JSON envelope (ok, data or error). It is a tool, not an agent: the observe, act and verify loop runs in you.

Shell syntax

Examples use a POSIX shell. In PowerShell, quote every ref ('@s8f3k2p9:e1'), because a bare @token is the splatting operator. Use $env:NAME = 'value' instead of export, and | ConvertFrom-Json instead of $(...) and jq. The Windows skill has the PowerShell forms.

First run

1. Run agent-desktop status. It reports the platform, permissions and supported_surfaces.
2. Run agent-desktop skills get platform. It loads the skill for the OS the binary runs on (macOS, Windows or Linux).
3. For flags and syntax, run agent-desktop <command> --help. This skill does not repeat flag lists.

The loop

Use find when you know the role or exact name. Otherwise map the app first and drill into one region.

agent-desktop snapshot --skeleton --app "Notes" -i --compact   # shallow map, children_count on cut branches
agent-desktop snapshot --root @s8f3k2p9:e3 -i --compact        # drill into one region
agent-desktop click @s8f3k2p9:e12                              # act on a qualified ref
agent-desktop snapshot --root @s8f3k2p9:e3 -i --compact        # verify: re-read the same region

• A small app needs no skeleton. Take a full snapshot -i.
• -i keeps interactive nodes only, so a row's static-text label is dropped. To tell which row a repeated button belongs to, drill that row's container with --root and leave out -i. On Windows and Linux that reads the row but does not make its button actionable: a button repeated in other rows is a twin in the window and its ref is refused (see Refs).
• A --root drill adds its refs to the same snapshot id. Refs outside the drilled subtree, and the drilled root itself, stay valid; refs that were already inside it are replaced, so an old ref there returns STALE_REF.
• Never skeleton a surface (--surface menu, sheet, alert). A surface is already focused.
• An action that opens a menu, sheet or alert lists it in data.surfaces. Target that overlay next.
• After an async step, use wait (see commands-system.md). A fixed sleep is a race.

Refs

• Output refs are qualified: @<snapshot_id>:e<N>, for example @s8f3k2p9:e1. Pass them to later commands as they are.
• Refs are valid for one snapshot. After any UI change, re-drill the affected region or take a new snapshot.
• Only addressable elements get refs. Static text and inert containers do not.
• A command re-identifies the element before it acts. On macOS the ref carries the element's own address, so identical twins each keep their ref. On Windows and Linux a ref resolves only when it was the only element in the window its snapshot captured with its role, native id, name and description, counted even below a skeleton or depth cut, and exactly one live element still matches. Identical twins there have no ref path: only --headed mouse-click --xy X,Y can choose one, it takes the foreground, and a Linux Wayland session refuses it.
• STALE_REF: the element is gone or no longer matches. details.kind is saved_ref_absent, or retained_object_stale on macOS. Take a fresh snapshot and use the new ref.
• AMBIGUOUS_TARGET: an identical element appeared (saved_ref_ambiguous), or the ref was not proven unique at capture (identity_not_unique). Repeating the ref or re-snapshotting identical twins gives the same refusal; act on a control that is unique in the window. identity_not_unique also follows a snapshot that could not read the whole window in time: retake it with a larger --timeout-ms.
• TIMEOUT with details.kind: resolution_identity_unknown: a live read did not answer, so identity is unproven. Nothing was sent; retry.
• SNAPSHOT_NOT_FOUND: the snapshot id expired. Snapshot again.

Delivery and retry

Action results carry data.disposition and errors carry error.disposition, each with delivery and retry. Observation commands such as snapshot have none on success; their errors, and every INVALID_ARGS refusal, carry not_delivered and retry: safe.

• Retry or substitute an action only when disposition.retry is safe. Only not_delivered is safe.
• Any other delivery value means the action may have landed. A repeat can click, type or submit twice, and toggle can undo itself.
• On a result that is not safe, read the live state (get, is, or a fresh snapshot) and decide from that. details.post_state helps when present.
• Branch on error.code and error.disposition. Message and suggestion text can change.
• details.retryable: false means waiting cannot change the outcome. Try a different approach.

Headless and headed

Ref actions are headless by default. They use semantic accessibility calls and do not take focus, move the cursor, synthesize keys or use the clipboard. If no semantic path exists, the action fails closed. Use the global --headed flag only when the user explicitly permits physical input, such as double-click, hover, drag, or focus. Never switch to headed mode to recover from a headless failure. Raw coordinates (--xy) never imply focus. Which actions need --headed differs by OS: read the platform skill.

References

Load one only when you need it: agent-desktop skills get desktop <reference>.