Premiere Pro MCP Server

Set Clip Duration

set_clip_duration

Set a timeline clip's visible duration by moving only its end while keeping the start fixed, including extending still images, with overlap and keyframe safeguards.

Instructions

Set one timeline clip's visible duration by moving only its timeline end (TrackItem.end) while keeping its start fixed. Pass exactly one of duration_seconds or end_seconds. Works for extending still images past their import length. Refuses to overlap the next clip on the same track, rejects shortening that would strand effect keyframes unless keyframe_policy is preserve, reads start/end back, and restores the original end if Premiere clamps or ignores the write (for example when video media has no handle left). Linked audio/video partners get the same change by default (include_linked), applied as the same end offset so partners with a J/L cut keep their offset; every clip is checked before any is changed. Use this instead of speed changes, which Premiere does not expose to scripting. Existing host Out padding below one sequence frame may be preserved or reduced, but never used to create additional padding. Non-still sources require readable ffprobe duration evidence and a readable sequence frame grid.

Input Schema

Name	Required	Description
`node_id`	Yes	Node ID of the timeline clip (track item) to resize
`end_seconds`	No	Target absolute timeline end (out-point) in seconds. Must be at least one frame after the clip's start. Specify exactly one of duration_seconds or end_seconds.
`include_linked`	No	Also apply the edit to the clip's linked audio/video partners, as Premiere does with linked selection (default: true).
`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.
`keyframe_policy`	No	When shortening, how to handle effect keyframes beyond the new visible length: reject (default) leaves the timeline unchanged; preserve keeps them and reports their count.
`duration_seconds`	No	Target visible duration in seconds, measured from the clip's current timeline start. Specify exactly one of duration_seconds or end_seconds.
`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
`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.

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv1.25.0Oct 24, 2026

addedInput schema / properties / idempotency_key

Added value: +{
+  "description": "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.",
+  "maxLength": 128,
+  "minLength": 1,
+  "pattern": "^[A-Za-z0-9._:-]+$",
+  "type": "string"
+}

addedOutput schema / properties / idempotency

Added value: +{
+  "additionalProperties": true,
+  "description": "Present when idempotency_key deduplicated this call: replayed is true when the original outcome was returned instead of running again.",
+  "type": "object"
+}

Changed3 schema fields changedv1.24.0Oct 12, 2026

addedInput schema / properties / expected_cep_target

Added value: +{
+  "additionalProperties": false,
+  "anyOf": [
+    {
+      "required": [
+        "sequence_id"
+      ]
+    },
+    {
+      "required": [
+        "source_item"
+      ]
+    }
+  ],
+  "description": "Optional reviewed CEP sequence/clip identity and exact tick ranges. Checked before every generated command; UXP refuses this CEP-only guard.",
+  "properties": {
+    "backend": {
+      "const": "cep",
+      "description": "Backend namespace for these IDs.",
+      "type": "string"
+    },
+    "clip": {
+      "additionalProperties": false,
+      "description": "Optional exact reviewed timeline clip.",
+      "properties": {
+        "effect": {
+          "additionalProperties": false,
+          "description": "Reviewed effect and parameter identity checked before mutation.",
+          "properties": {
+            "display_name": {
+              "description": "Optional exact host display name.",
+              "maxLength": 512,
+              "minLength": 1,
+              "type": "string"
+            },
+            "match_name": {
+              "description": "Effect match name from host inspection.",
+              "maxLength": 512,
+              "minLength": 1,
+              "type": "string"
+            },
+            "parameter_index": {
+              "description": "Inspected zero-based parameter index.",
+              "maximum": 255,
+              "minimum": 0,
+              "type": "integer"
+            },
+            "parameter_name": {
+              "description": "Exact inspected parameter name.",
+              "maxLength": 512,
+              "minLength": 1,
+              "type": "string"
+            }
+          },
+          "required": [
+            "match_name",
+            "parameter_index",
+            "parameter_name"
+          ],
+          "type": "object"
+        },
+        "end_ticks": {
+          "description": "Exact expected exclusive timeline end ticks.",
+          "pattern": "^-?\\d{1,30}$",
+          "type": "string"
+        },
+        "in_ticks": {
+          "description": "Exact expected source In ticks.",
+          "pattern": "^-?\\d{1,30}$",
+          "type": "string"
+        },
+        "node_id": {
+          "description": "Stable CEP node ID.",
+          "maxLength": 512,
+          "minLength": 1,
+          "type": "string"
+        },
+        "out_ticks": {
+          "description": "Exact expected exclusive source Out ticks.",
+          "pattern": "^-?\\d{1,30}$",
+          "type": "string"
+        },
+        "project_item_id": {
+          "description": "Expected source project-item node ID.",
+          "maxLength": 512,
+          "minLength": 1,
+          "type": "string"
+        },
+        "start_ticks": {
+          "description": "Exact expected timeline start ticks.",
+          "pattern": "^-?\\d{1,30}$",
+          "type": "string"
+        },
+        "track_index": {
+          "description": "Expected zero-based track index; identity still checked.",
+          "maximum": 255,
+          "minimum": 0,
+          "type": "integer"
+        },
+        "track_type": {
+          "description": "Expected media track group.",
+          "enum": [
+            "video",
+            "audio"
+          ],
+          "type": "string"
+        }
+      },
+      "required": [
+        "node_id",
+        "track_type",
+        "track_index"
+      ],
+      "type": "object"
+    },
+    "project_document_id": {
+      "description": "Exact Premiere project document ID observed during review.",
+      "maxLength": 512,
+      "minLength": 1,
+      "type": "string"
+    },
+    "sequence_id": {
+      "description": "Stable expected active sequence ID.",
+      "maxLength": 512,
+      "minLength": 1,
+      "type": "string"
+    },
+    "source_item": {
+      "additionalProperties": false,
+      "description": "Reviewed source identity for a source-only operation.",
+      "properties": {
+        "media_path": {
+          "description": "Optional exact source-media path.",
+          "maxLength": 4096,
+          "minLength": 1,
+          "type": "string"
+        },
+        "node_id": {
+          "description": "Exact project-item node ID.",
+          "maxLength": 512,
+          "minLength": 1,
+          "type": "string"
+        }
+      },
+      "required": [
+        "node_id"
+      ],
+      "type": "object"
+    }
+  },
+  "required": [
+    "backend"
+  ],
+  "type": "object"
+}

addedInput schema / properties / expected_project_path

Added value: +{
+  "description": "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.",
+  "maxLength": 4096,
+  "minLength": 1,
+  "type": "string"
+}

addedOutput schema / properties / receipt

Added value: +{
+  "additionalProperties": true,
+  "description": "Versioned common mutation receipt; success never implies rendered verification.",
+  "type": "object"
+}

Changed3 schema fields changedv1.18.6Sep 30, 2026

addedInput schema / additionalProperties
```
Added value: +false
```

addedInput schema / properties / include_linked

Added value: +{
+  "description": "Also apply the edit to the clip's linked audio/video partners, as Premiere does with linked selection (default: true).",
+  "type": "boolean"
+}

changedOutput schema / properties / data / description

Previous value: -"Tool-specific result data when ok is true."New value: +"Tool-specific result data when ok is true; on failure, diagnostic detail when the tool provides it."

Addedv1.18.0Sep 23, 2026

TDQS

A4.6/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Goes well beyond the annotations: pre-validates every clip before mutating any, rolls back the original end if Premiere clamps the write, refuses overlaps, discloses Out-padding behavior, and describes how linked partners receive the same end offset to preserve J/L cuts. Safety-relevant failure modes are named concretely rather than left implicit.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

A single dense paragraph that front-loads the core action and mechanism before piling on edge cases; nearly every clause carries information, though the tail (ffprobe evidence, frame grid) is compressed enough to read as a run-on.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists and rich nested validation params (expected_cep_target, expected_project_path) are schema-documented, so the description's job is preconditions and side effects — both covered, including the ffprobe/frame-grid requirements needed for non-still sources.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is already 100%, so 3 is the baseline; the description adds real semantics on top: the exactly-one-of constraint on duration_seconds/end_seconds and the rationale that include_linked applies as an end offset so partners with a J/L cut keep their offset. keyframe_policy and idempotency_key are largely restated from the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

Names a specific verb and resource (set one timeline clip's visible duration) and pins the mechanism (moves TrackItem.end, keeps start fixed), which clearly separates it from trim_clip, set_clip_start_time, move_clip and speed_change.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly routes the agent away from speed changes ("Use this instead of speed changes, which Premiere does not expose to scripting") and states preconditions (readable ffprobe duration, readable sequence frame grid) plus the one-of duration_seconds/end_seconds rule. It does not explicitly contrast with trim_clip or set_item_in_out, so it falls short of full alternative coverage.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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