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MCP for Unity v10 Release Candidate Notes

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MCP for Unity v10 Release Candidate Notes

These notes cover the v10 release candidate: the full major-version change from v9.0.0, the new AI asset generation/import surface, secure provider-key storage, Blender/local-file handoff, and the README/docs/brand refresh.

For this comparison, v9 means v9.0.0, not the last v9 patch. The v9.7.3 tag is still useful for the release-to-release changelog, but it already contains much of the v9 tool expansion.

What changed since v9.0.0

At v9.0.0, MCP for Unity exposed 29 MCP tool entrypoints around the core Unity Editor loop: scenes, GameObjects, components, scripts, prefabs, assets, materials, shaders, VFX, console reads, editor refresh, async tests, custom tools, and batch execution.

The v10 release candidate exposes 47 MCP tool entrypoints across 10 groups: core, animation, asset_gen, docs, probuilder, profiling, scripting_ext, testing, ui, and vfx.

Areav9.0.0 baselinev10 release candidate
Tool catalog29 MCP tool entrypoints, with most tools registered directly into one visible surface.47 MCP tool entrypoints across grouped domains.
Tool visibilityNo decorator-level group metadata and no manage_tools workflow for user-controlled visibility.Tool registry has named groups; core is enabled by default and non-core groups are opt-in.
Editor automation domainsCore scene/object/component/script/asset/prefab/material/shader/VFX/test/editor operations.Adds build orchestration, camera/Cinemachine control, render pipeline and graphics operations, package management, physics, animation, UI Toolkit, profiling, ProBuilder, and procedural texture generation.
Asset creation/importExisting asset management and VFX/shader/script tools could create or modify project content, but external generation providers were not part of the product surface.Adds the asset_gen group for Tripo/Meshy model generation, fal.ai/OpenRouter image generation, Sketchfab import, and local FBX/OBJ/glTF handoff from tools such as Blender.
API lookup and docsAPI discovery depended on external docs or local project inspection.Adds unity_docs and unity_reflect, plus generated tool/resource reference docs.
Safety modelCore tool execution, custom tools, async test polling, and instance routing were present.Adds group-gated high-power tools, secure provider-key storage in Unity, project-scoped import hardening, archive/path validation, and more test coverage around transport, tool registry, provider adapters, and Unity compatibility.
Editor UI and docsThe window focused on connection/client setup and the docs grew around accumulated features.Adds tool/resource visibility flows, Asset Gen setup, glTFast dependency guidance, refreshed README/docs navigation, icons/social assets, and consistent "MCP for Unity" product naming.

Added MCP tool entrypoints since v9.0.0: execute_code, generate_image, generate_model, import_model, import_model_file, manage_animation, manage_build, manage_camera, manage_graphics, manage_packages, manage_physics, manage_probuilder, manage_profiler, manage_texture, manage_tools, manage_ui, unity_docs, and unity_reflect.

What v10 is about

  1. A larger grouped tool surface - the catalog grows from 29 to 47 MCP tool entrypoints, with high-power domains split into opt-in groups.
  2. Asset generation and import - first-class MCP tools for generating 3D models, generating 2D images, importing marketplace models, and handing off local files from tools like Blender.
  3. Safer agent operations - provider keys stay in the Unity Editor, tools are opt-in by group, long-running jobs are explicit and pollable, and file writes are constrained to project assets.
  4. Clearer product surface - refreshed README, docs site, branding, and distribution metadata.
  5. Release confidence - Python tests, Unity compile checks, docs builds, and compatibility shims for the wide Unity support window.

AI Asset Generation

The headline v10 feature is the new asset_gen tool group. It is disabled by default like other non-core tool groups, and can be enabled with manage_tools.

ToolPurpose
generate_modelGenerate 3D models from text or image prompts through providers such as Tripo and Meshy.
generate_imageGenerate 2D images through providers such as fal.ai and OpenRouter.
import_modelSearch and import downloadable Sketchfab models.
import_model_fileImport a local model file already on disk, such as an FBX/OBJ/glTF exported from Blender.

Generation and import jobs are asynchronous. A request returns a job_id, and the client polls action="status" until the job completes or fails.

Providers

  • 3D generation: Tripo (default) and Meshy.
  • 3D import: Sketchfab.
  • 2D image generation: fal.ai (default) and OpenRouter.

Setup

  1. Open Window > MCP for Unity > Asset Gen and enter provider API keys.
  2. Enable the tools with manage_tools; the asset_gen group is off by default.
  3. Install glTFast from the Dependencies tab for GLB output/import. FBX import does not require glTFast.

Provider keys are stored in the OS secure store and are not written to project assets or EditorPrefs.

Usage examples

Generation runs through MCP tools or the asset-gen CLI, not from the Unity GUI. Long-running jobs return a job_id; call action="status" with that job_id until the job completes.

text
generate_model action=generate provider=tripo mode=text prompt="a low-poly oak tree" format=fbx
generate_model action=generate provider=meshy mode=image image_path=Assets/refs/chair.png
generate_image action=generate provider=fal mode=text prompt="a pixel-art coin"
import_model action=search query="wooden chair"
import_model action=import uid=<uid from search>

Provider caveats

  • image_url points at a hosted image.
  • image_path points at a local file, commonly under Assets/.
  • Meshy image-to-3D and fal/OpenRouter image-to-image support local image_path inputs by sending the image inline as a base64 data URI.
  • Tripo image-to-3D currently needs a hosted image_url.
  • transparent sets the Unity texture import flag only; fal/FLUX does not provide transparent-background generation.
  • width and height are forwarded to fal; OpenRouter's chat API has no size control.

Provider keys

Asset providers are bring-your-own-key. Keys are entered in the Unity Editor's Asset Gen tab and stored in the operating system secure store:

  • macOS: Keychain
  • Windows: Credential Manager
  • Linux: libsecret / Secret Service compatible tooling

Keys are not written to project assets, EditorPrefs, generated docs, or MCP tool parameters. The MCP client can request a generation job, but it does not receive provider credentials.

Local image inputs

v10 distinguishes hosted image inputs from local project images:

  • image_url points at an externally hosted image.
  • image_path points at a local file, commonly under Assets/.

Meshy image-to-3D and fal/OpenRouter image-to-image can accept local image files by sending the image data inline as a base64 data URI. Tripo image-to-3D still requires a hosted image_url until an upload flow is wired.

Blender handoff

The import_model_file tool creates a clean boundary between DCC generation and Unity import:

  1. The modeling tool creates or exports the asset.
  2. MCP for Unity imports the file with import_model_file.
  3. The Unity agent uses existing scene, material, prefab, and build tools to wire the asset into the project.

With BlenderMCP connected, a modeling workflow can export the current Blender model and import it through import_model_file (FBX by default). BlenderMCP handles modeling or generation; MCP for Unity handles import and scene placement. The Asset Gen tab shows a best-effort "Blender app detected" status, but BlenderMCP itself is configured in the AI client and is not detectable from Unity.

This is a handoff, not MCP for Unity controlling Blender directly.

Safety model

Opt-in tool group

asset_gen is not part of the default core tool set. Users must explicitly enable it with manage_tools.

Project-scoped imports

Generated and imported assets resolve into the Unity project's Assets/ folder, with traversal and unsafe paths rejected. Archives are extracted through allowlisted import paths and extensions rather than blindly writing every file a provider returns.

No hidden spend

Generation calls go to third-party providers using the user's own API keys.

  • MCP for Unity does not bundle provider credits.
  • Provider pricing, rate limits, and content policies are controlled by the provider.
  • Enable the tool group only when you intend to call generation or import providers.

Docs and brand refresh

v10 also updates the project front door:

  • README trimmed into a clearer front door.
  • Docs site reorganized around Getting Started, Guides, Reference, Architecture, Contributing, Migrations, and Releases.
  • Tool reference pages are generated from the tool registry.
  • Distribution and analytics docs are explicit about what is measured and what is not.
  • Branding now consistently uses MCP for Unity in user-facing UI and docs.

Compatibility posture

v10 continues the existing compatibility promise:

  • Unity 2021.3 LTS remains the package floor.
  • Unity 6.x stays in the supported matrix.
  • Known Unity API changes route through compatibility helpers under MCPForUnity/Runtime/Helpers/.
  • Contributors touching shims or version-gated APIs run tools/check-unity-versions.sh against installed Unity Hub editors.

Upgrade notes from v9

  1. Update the Unity package to v10. During RC testing, use the beta branch.
  2. Reconfigure MCP clients if the package prompts you to.
  3. Install optional dependencies only when needed. GLB import uses glTFast; FBX import does not require that package.
  4. Enable asset_gen explicitly with manage_tools before calling asset generation tools.
  5. Add provider keys in Unity, not in MCP client config files.
  6. Keep generated assets under review before committing them.

What is intentionally not in v10

  • No hosted MCP for Unity asset-generation credits.
  • No guarantee that every provider supports every input mode.
  • No automatic BlenderMCP configuration from Unity.
  • No promise that provider-generated assets are production-ready without artist review.
  • No change to the rule that non-core tool groups start disabled.

Final comparison

Major-version comparison: https://github.com/CoplayDev/unity-mcp/compare/v9.0.0...v10.0.0

v9.7.3 patch comparison: https://github.com/CoplayDev/unity-mcp/compare/v9.7.3...v10.0.0

Troubleshooting

asset_gen tools do not appear

The asset_gen group is disabled by default. Enable it with manage_tools:

text
manage_tools action=activate group=asset_gen

If the tools still do not appear, refresh/reconnect the MCP server in the client. Some clients cache tool lists until the server is restarted or refreshed.

Provider key missing

Generation providers are bring-your-own-key. Add keys in Unity's Asset Gen tab. Do not place provider keys in MCP client config files, prompts, project assets, or generated docs.

GLB import fails or has missing geometry/materials

GLB/glTF import depends on glTFast. Install it from the Dependencies tab or via Package Manager before importing GLB assets. FBX imports do not require glTFast.

Tripo image-to-3D rejects image_path

Tripo image-to-3D currently needs a hosted image_url. Local image_path inputs are supported by Meshy image-to-3D and fal/OpenRouter image-to-image, where the image can be sent inline as a base64 data URI.

Generated or imported files are larger than expected

Provider output can include large binary assets. Review generated files before committing them, keep generated output under Assets/Generated/ when possible, and avoid committing experimental provider output that is not needed by the project.

Archive import is rejected

Archive extraction is intentionally constrained. Provider archives may be rejected when they contain unsupported extensions, traversal paths, scripts, or files outside the import allowlist. Import the model again with a supported format or inspect the archive before bringing it into the Unity project.