figma-migration-deep-dive

Figma Migration Deep Dive

Overview

Automate migration of design data between Figma files, from other tools to Figma, or from Figma styles to the Variables API. Covers inventory, extraction, transformation, and validation.

Prerequisites

• Source and destination Figma file keys
• FIGMA_PAT with file_content:read and file_variables:write (Enterprise) scopes
• Understanding of source file structure

Instructions

Step 1: Inventory Source File

const PAT = process.env.FIGMA_PAT!;

async function inventoryFile(fileKey: string) {
  const res = await fetch(
    `https://api.figma.com/v1/files/${fileKey}`,
    { headers: { 'X-Figma-Token': PAT } }
  );
  const file = await res.json();

  const inventory = {
    name: file.name,
    pages: file.document.children.map((p: any) => p.name),
    componentCount: Object.keys(file.components).length,
    styleCount: Object.keys(file.styles).length,
    styles: {
      fills: Object.values(file.styles).filter((s: any) => s.style_type === 'FILL').length,
      text: Object.values(file.styles).filter((s: any) => s.style_type === 'TEXT').length,
      effects: Object.values(file.styles).filter((s: any) => s.style_type === 'EFFECT').length,
      grids: Object.values(file.styles).filter((s: any) => s.style_type === 'GRID').length,
    },
  };

  // Count total nodes
  let nodeCount = 0;
  function countNodes(node: any) {
    nodeCount++;
    if (node.children) node.children.forEach(countNodes);
  }
  countNodes(file.document);
  (inventory as any).totalNodes = nodeCount;

  return inventory;
}

// Usage
const inv = await inventoryFile(process.env.FIGMA_FILE_KEY!);
console.log(`File: ${inv.name}`);
console.log(`Pages: ${inv.pages.join(', ')}`);
console.log(`Components: ${inv.componentCount}, Styles: ${inv.styleCount}`);
console.log(`Total nodes: ${(inv as any).totalNodes}`);

Step 2: Extract Styles from Source

async function extractAllStyles(fileKey: string) {
  const file = await fetch(
    `https://api.figma.com/v1/files/${fileKey}`,
    { headers: { 'X-Figma-Token': PAT } }
  ).then(r => r.json());

  const styleNodeIds = Object.keys(file.styles);
  const nodesRes = await fetch(
    `https://api.figma.com/v1/files/${fileKey}/nodes?ids=${styleNodeIds.join(',')}`,
    { headers: { 'X-Figma-Token': PAT } }
  ).then(r => r.json());

  const extracted = [];
  for (const [nodeId, styleMeta] of Object.entries(file.styles) as any[]) {
    const node = nodesRes.nodes[nodeId]?.document;
    if (!node) continue;

    extracted.push({
      name: styleMeta.name,
      type: styleMeta.style_type,
      nodeId,
      data: {
        fills: node.fills,
        strokes: node.strokes,
        effects: node.effects,
        style: node.style,       // typography
        characters: node.characters,
      },
    });
  }

  return extracted;
}

Step 3: Transform and Map to Target

// Map extracted styles to design tokens JSON
interface MigrationToken {
  name: string;
  category: 'color' | 'typography' | 'effect';
  source: { file: string; nodeId: string };
  value: any;
}

function transformStyles(styles: any[], sourceFileKey: string): MigrationToken[] {
  return styles.map(style => {
    switch (style.type) {
      case 'FILL':
        const fill = style.data.fills?.[0];
        return {
          name: style.name,
          category: 'color' as const,
          source: { file: sourceFileKey, nodeId: style.nodeId },
          value: fill?.color
            ? {
                r: Math.round(fill.color.r * 255),
                g: Math.round(fill.color.g * 255),
                b: Math.round(fill.color.b * 255),
                a: fill.color.a ?? 1,
              }
            : null,
        };
      case 'TEXT':
        return {
          name: style.name,
          category: 'typography' as const,
          source: { file: sourceFileKey, nodeId: style.nodeId },
          value: style.data.style
            ? {
                fontFamily: style.data.style.fontFamily,
                fontSize: style.data.style.fontSize,
                fontWeight: style.data.style.fontWeight,
                lineHeight: style.data.style.lineHeightPx,
              }
            : null,
        };
      default:
        return {
          name: style.name,
          category: 'effect' as const,
          source: { file: sourceFileKey, nodeId: style.nodeId },
          value: style.data.effects,
        };
    }
  }).filter(t => t.value !== null);
}

Step 4: Write to Target (Variables API)

// Enterprise only: create variables in the target file
async function migrateToVariables(
  targetFileKey: string,
  tokens: MigrationToken[]
) {
  const colorTokens = tokens.filter(t => t.category === 'color');

  // Create variable collection and variables
  const payload = {
    variableCollections: [{
      action: 'CREATE' as const,
      id: 'temp_collection_1',
      name: 'Migrated Colors',
    }],
    variables: colorTokens.map((token, i) => ({
      action: 'CREATE' as const,
      id: `temp_var_${i}`,
      name: token.name.replace(/\//g, '/'), // preserve Figma group paths
      variableCollectionId: 'temp_collection_1',
      resolvedType: 'COLOR' as const,
      codeSyntax: { WEB: `--${token.name.toLowerCase().replace(/[\s/]+/g, '-')}` },
    })),
    variableModeValues: colorTokens.map((token, i) => ({
      variableId: `temp_var_${i}`,
      modeId: '', // Will use default mode
      value: {
        r: token.value.r / 255,
        g: token.value.g / 255,
        b: token.value.b / 255,
        a: token.value.a,
      },
    })),
  };

  const res = await fetch(
    `https://api.figma.com/v1/files/${targetFileKey}/variables`,
    {
      method: 'POST',
      headers: {
        'X-Figma-Token': PAT,
        'Content-Type': 'application/json',
      },
      body: JSON.stringify(payload),
    }
  );

  if (!res.ok) throw new Error(`Variable creation failed: ${res.status} ${await res.text()}`);
  return res.json();
}

Step 5: Validation

async function validateMigration(
  sourceFileKey: string,
  targetFileKey: string
): Promise<{ passed: boolean; issues: string[] }> {
  const sourceStyles = await extractAllStyles(sourceFileKey);
  const targetVars = await fetch(
    `https://api.figma.com/v1/files/${targetFileKey}/variables/local`,
    { headers: { 'X-Figma-Token': PAT } }
  ).then(r => r.json());

  const issues: string[] = [];
  const targetNames = new Set(
    Object.values(targetVars.meta.variables).map((v: any) => v.name)
  );

  for (const style of sourceStyles) {
    if (style.type === 'FILL' && !targetNames.has(style.name)) {
      issues.push(`Missing in target: ${style.name}`);
    }
  }

  return { passed: issues.length === 0, issues };
}

Output

• Source file inventoried (components, styles, nodes)
• Styles extracted and transformed to tokens
• Tokens written to target file via Variables API
• Migration validated with comparison report

Error Handling

Error	Cause	Solution
403 on Variables POST	Not Enterprise	Use JSON export instead of Variables API
Duplicate variable names	Name collision in target	Add prefix/suffix to migrated names
Missing node data	Node deleted between fetch and read	Re-fetch with error handling
Large file timeout	File >100MB	Use /nodes endpoint for specific pages

Resources

• Figma Variables API
• Figma File Endpoints
• Design Tokens Format

Next Steps

For advanced troubleshooting, see figma-advanced-troubleshooting.