blender-api-compatibility

Blender API Compatibility Skill

Version: 3.1.1 Last Updated: 2026-09-02 Dependencies: Blender 5.1+

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Breaking Changes (4.2 -> 5.1)

All changes below are tested and confirmed. The Blender MCP has full context, so bpy.ops works normally - the old HTTP Bridge limitation of 80% operator failure no longer applies.

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QUICK START

API Error Diagnosis

Step 1: Identify the error pattern

# Common error signatures:
# AttributeError involving 'BLENDER_EEVEE'  -> Render engine renamed
# KeyError: 'GEOMETRY_NODES'                -> Modifier type renamed
# KeyError/AttributeError on BSDF inputs    -> Input names changed
# RuntimeError: "Cannot find node type"     -> Node type removed/renamed
# TypeError: enum "FFMPEG" not found        -> Set media_type = 'VIDEO' first (5.0+)
# AttributeError on 'sequences'             -> VSE renamed to strips/strips_all (5.0+)

Step 2: Apply the correct migration pattern (see workflows below)

Step 3: Verify in Blender

import bpy

# Quick test: check current render engine
print(bpy.context.scene.render.engine)  # Should print BLENDER_EEVEE_NEXT or CYCLES

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STANDARD WORKFLOWS

Workflow 1: EEVEE -> EEVEE_NEXT Migration

Use When: Code references BLENDER_EEVEE or old EEVEE properties

import bpy

# [FAIL] REMOVED in 4.5.0+
# bpy.context.scene.render.engine = 'BLENDER_EEVEE'
# scene.eevee.use_bloom = True
# scene.eevee.use_ssr = True
# scene.eevee.use_motion_blur = True

# [OK] Render engine
bpy.context.scene.render.engine = 'BLENDER_EEVEE_NEXT'

# [OK] Bloom -> Compositor Glare node
scene = bpy.context.scene
scene.use_nodes = True
nodes = scene.node_tree.nodes
links = scene.node_tree.links
glare = nodes.new(type='CompositorNodeGlare')
glare.glare_type = 'FOG_GLOW'   # closest to old EEVEE bloom
glare.threshold = 0.8

# [OK] Motion blur -> render settings
scene.render.use_motion_blur = True
scene.render.motion_blur_shutter = 0.5

# [OK] Screen space reflections -> ray tracing
scene.eevee.use_raytracing = True