Supported formats & upload limits

The machine-readable source of truth is /api/public/v1/capabilities — agents should read that endpoint before every upload rather than hardcoding any value below. If this page and the capabilities feed disagree, the feed wins.

Product rule

Every model format accepted for upload by maichine must be eligible to enter the Production workflow. Preview-only model uploads are not supported.

An agent must never upload a preview-only file as a project version or as a "color reference" fallback — the same Production-eligible artifact that a user reviews in the preview is what enters production.

Currently accepted upload formats

Upload limits

• Max file size: 25 MB per upload, on every path (browser, REST, MCP).
• Daily quota per account: up to 200 uploads and 500 MB combined.
• Uploads that exceed the limit fail with a structured error and the version is not persisted.

Rejected formats

New uploads in any other format are rejected with the stable error contract:

{
  "error": "This format is not supported for Production.",
  "code": "FORMAT_NOT_PRODUCTION_SUPPORTED",
  "details": { "format": "glb" },
  "action_url": "/docs/supported-formats"
}

This applies to .glb, .obj, .ply, .fbx, and any other format not listed in the capabilities feed's formats.upload.

Legacy viewer-only support

Historical project versions previously uploaded in .obj, .glb, .ply, or .fbx can still render read-only in the preview so a human can inspect them, but:

• they are labeled Legacy preview-only — not eligible for Production,
• they cannot be selected as the Production version in the configurator,
• they do not displace a newer or older Production-eligible version as the project's "current" production candidate, and
• no new upload in one of these formats is accepted, ever.

3MF safety limits

.3mf archives are parsed defensively. An upload is rejected if it exceeds any of:

• 250 MB extracted
• 100:1 compression ratio
• 200 zip entries
• 5,000 objects
• 5,000,000 triangles
• 32 texture files or 20 MB total texture bytes

DOCTYPE, ENTITY, and external DTD references (SYSTEM / PUBLIC) are refused before parsing. Paths that escape the archive root (.., absolute paths, drive letters) are refused. A spec-conformant 3MF core namespace (xmlns="http://schemas.microsoft.com/3dmanufacturing/core/2015/02") and standard OPC relationship type URIs are accepted — they are part of the specification, not an XXE vector.

Guidance for agents

• Fetch /api/public/v1/capabilities at the start of every task and again before export; export directly into a format listed under formats.upload.
• Prefer .3mf whenever the model has more than one color or logical part.
• Use .stl for simple single-color geometry.
• If your tools cannot produce a Production-eligible artifact, stop and report the concrete export blocker. Never upload a preview-only format as a fallback and never present a preview-only file as a finished maichine version.
• If two attempts fail with the same format or compatibility cause, stop and report a platform issue rather than inventing more proprietary file variants.