diff --git a/src/lib/generators/__tests__/generateFlaskBlueprint.test.ts b/src/lib/generators/__tests__/generateFlaskBlueprint.test.ts
new file mode 100644
index 0000000..6db0602
--- /dev/null
+++ b/src/lib/generators/__tests__/generateFlaskBlueprint.test.ts
@@ -0,0 +1,73 @@
+import { describe, expect, it } from 'vitest'
+
+import type { FlaskBlueprint } from '@/types/project'
+
+import { generateFlaskBlueprint } from '../generateFlaskBlueprint'
+
+const isValidIdentifier = (name: string): boolean => /^[A-Za-z_][A-Za-z0-9_]*$/.test(name)
+
+const extractBlueprintVariable = (code: string): { variable: string; name: string } => {
+  const match = code.match(/^([A-Za-z_][A-Za-z0-9_]*)_bp = Blueprint\('([^']+)'/m)
+  if (!match) {
+    throw new Error('Blueprint definition not found.')
+  }
+  return { variable: `${match[1]}_bp`, name: match[2] }
+}
+
+const extractFunctionNames = (code: string): string[] => {
+  return Array.from(code.matchAll(/^def ([A-Za-z_][A-Za-z0-9_]*)\(\):/gm)).map(match => match[1])
+}
+
+const extractDecoratorBlueprints = (code: string): string[] => {
+  return Array.from(code.matchAll(/^@([A-Za-z_][A-Za-z0-9_]*)\.route/gm)).map(match => match[1])
+}
+
+describe('generateFlaskBlueprint identifier sanitization', () => {
+  it('creates valid, consistent identifiers for tricky endpoint names', () => {
+    const blueprint: FlaskBlueprint = {
+      id: 'bp-1',
+      name: 'User Auth',
+      urlPrefix: '/auth',
+      description: 'Auth endpoints',
+      endpoints: [
+        {
+          id: 'ep-1',
+          name: 'get-user',
+          description: 'Fetch a user',
+          method: 'GET',
+          path: '/user'
+        },
+        {
+          id: 'ep-2',
+          name: '2fa',
+          description: 'Two factor auth',
+          method: 'POST',
+          path: '/2fa'
+        },
+        {
+          id: 'ep-3',
+          name: 'user.v1',
+          description: 'User v1 endpoint',
+          method: 'GET',
+          path: '/user/v1'
+        }
+      ]
+    }
+
+    const code = generateFlaskBlueprint(blueprint)
+    const blueprintDefinition = extractBlueprintVariable(code)
+    const functionNames = extractFunctionNames(code)
+    const decoratorBlueprints = extractDecoratorBlueprints(code)
+
+    expect(isValidIdentifier(blueprintDefinition.name)).toBe(true)
+    expect(isValidIdentifier(blueprintDefinition.variable)).toBe(true)
+    expect(blueprintDefinition.variable).toBe('user_auth_bp')
+    expect(blueprintDefinition.name).toBe('user_auth')
+    expect(new Set(decoratorBlueprints)).toEqual(new Set([blueprintDefinition.variable]))
+
+    expect(functionNames).toEqual(['get_user', '_2fa', 'user_v1'])
+    functionNames.forEach(name => {
+      expect(isValidIdentifier(name)).toBe(true)
+    })
+  })
+})
diff --git a/src/lib/generators/generateFlaskBlueprint.ts b/src/lib/generators/generateFlaskBlueprint.ts
index 0279173..1cd8cc7 100644
--- a/src/lib/generators/generateFlaskBlueprint.ts
+++ b/src/lib/generators/generateFlaskBlueprint.ts
@@ -1,6 +1,19 @@
 import { FlaskBlueprint } from '@/types/project'
 import { sanitizeIdentifier } from './sanitizeIdentifier'
 
+function toPythonIdentifier(value: string, fallback: string): string {
+  const normalized = value
+    .toLowerCase()
+    .replace(/[^a-z0-9_]/g, '_')
+    .replace(/_+/g, '_')
+    .replace(/^_+|_+$/g, '')
+  let safe = normalized || fallback
+  if (/^[0-9]/.test(safe)) {
+    safe = `_${safe}`
+  }
+  return safe
+}
+
 export function generateFlaskBlueprint(blueprint: FlaskBlueprint): string {
   let code = `from flask import Blueprint, request, jsonify\n`
   code += `from typing import Dict, Any\n\n`