Speed Change
speed_changeAttempts to change a timeline clip's playback speed; always fails before mutation because Premiere lacks a speed setter—use set_clip_duration to change clip duration instead.
Instructions
Unavailable: Premiere's documented ExtendScript and UXP APIs have no setter for a timeline clip's speed (only getters), and the undocumented QE setSpeed is deliberately not used. Always fails before mutation. To change how long a clip runs on the timeline, use set_clip_duration.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| node_id | Yes | Node ID of the clip | |
| reverse | No | Reverse playback direction (default: false) | |
| speed_percent | Yes | Speed as percentage (100 = normal, 200 = double, 50 = half) | |
| idempotency_key | No | Optional client-chosen key (1-128 chars of A-Z a-z 0-9 . _ : -) for this intended edit. Pass a fresh key per edit and reuse it only when retrying that same edit, for example after a client-side timeout. A repeat with the same tool, key and arguments is not run again: while the first call is running it fails with IDEMPOTENCY_IN_PROGRESS (poll get_last_operations); after it finished it returns the original outcome marked replayed. A definite failure with nothing applied (receipt outcome not_applied) may be retried with the same key. Reusing a key with different arguments fails with IDEMPOTENCY_KEY_REUSED. Scoped to this MCP session (the stdio server process or one HTTP session) and held in memory only (200 keys, 1 hour); it does not survive a restart or reconnect. Read-only invocations are never deduplicated. | |
| expected_cep_target | No | Optional reviewed CEP sequence/clip identity and exact tick ranges. Checked before every generated command; UXP refuses this CEP-only guard. | |
| expected_project_path | No | Optional absolute saved-project path. Every generated CEP command refuses before its body when the active project differs or is unsaved. UXP commands refuse this CEP-only guard; local-only tools do not inspect Premiere. Omit to keep existing behavior. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| ok | Yes | Whether the tool completed successfully. | |
| data | No | Tool-specific result data when ok is true; on failure, diagnostic detail when the tool provides it. | |
| tool | Yes | The registered MCP tool name. | |
| error | No | Failure detail when ok is false. | |
| receipt | No | Versioned common mutation receipt; success never implies rendered verification. | |
| idempotency | No | Present when idempotency_key deduplicated this call: replayed is true when the original outcome was returned instead of running again. |