remotion-dev/remotion · error · Error

sequenceId must be a non-empty string.

Error message

sequenceId must be a non-empty string.

What it means

The Web MCP selectSequence tool requires a composition to be currently selected in Studio. If currentComposition is null (nothing selected yet), the tool throws before looking up the sequence.

Source

Thrown at packages/studio/src/components/WebMcp.tsx:966

					title: 'Select Studio sequence',
					description:
						'Select and reveal a sequence in the current Remotion Studio timeline by the sequence ID returned by get_sequences.',
					inputSchema: {
						type: 'object',
						properties: {
							sequenceId: {
								type: 'string',
								minLength: 1,
								description: 'The sequence ID returned by get_sequences.',
							},
						},
						required: ['sequenceId'],
						additionalProperties: false,
					},
					annotations: {readOnlyHint: false},
					execute: ({sequenceId}) => {
						if (typeof sequenceId !== 'string' || sequenceId.length === 0) {
							throw new Error('sequenceId must be a non-empty string.');
						}

						const compositionId = currentCompositionRef.current;
						if (compositionId === null) {
							throw new Error('No composition is currently selected.');
						}

						if (!canSelectRef.current) {
							throw new Error('Studio sequence selection is unavailable.');
						}

						const timelineTrack = getCurrentTimeline().find(
							(candidate) => candidate.sequence.id === sequenceId,
						);
						if (!timelineTrack) {
							throw new Error(
								`Sequence ${sequenceId} not found in the current composition.`,
							);

View on GitHub (pinned to b2f4e34732)

Solutions

1. Call the selectComposition MCP tool first to open a composition
2. Manually select a composition in Studio before running the sequence tool
3. Check the currentComposition state via MCP before calling selectSequence

if (currentComposition === null) { /* call selectComposition first */ }

try { ... } catch (e) { if (e.message === 'No composition is currently selected.') { await selectComposition(...); await retry(); } }

When it happens

Trigger: Calling selectSequence before any composition is open in Studio, e.g. right after Studio loads with no composition chosen.

Common situations: Automated MCP scripts that skip the selectComposition step or run against a fresh Studio instance.

Related errors

• compositionName must be a string.
• Job is not running
• The artifact filename ${artifact.filename} was emitted more
• Composition ${compositionName} not found.
• No composition is currently selected.

AI-assisted analysis of remotion-dev/remotion@b2f4e34732 (2026-08-28). Data as JSON: /api/errors/ed89755e38094048. Report an issue: GitHub.