How is this different from Autodesk Platform Services, or open-source CAD libraries?

Different shapes of solution. Autodesk Platform Services is a first-party platform oriented around viewing and model derivatives — deep, and correspondingly larger to integrate. ezdxf is an excellent in-process DXF library, but it does not read DWG, so you still need a conversion step in front of it; LibreDWG reads DWG directly, with coverage that varies across the long tail of revisions. Running the ODA File Converter yourself is the industry-standard conversion path (CADLens uses it internally) and means operating a licensed, GUI-era binary headlessly with a queue in front of it. CADLens is the hosted abstraction over that work: one REST endpoint, a versioned output schema, per-parse pricing, and no conversion infrastructure of your own.

What exactly do I get back in the JSON?

File metadata (units, layers, drawing extent), and a per-sheet structure — each sheet carries its own layers and entities (polylines, arcs, circles, splines, text, hatches, inserts), each entity with coordinates, category, bounding box, and computed metrics — plus signed URLs to rendered PNG previews, one per sheet. Schema is versioned (currently 2.0.0) and we never make breaking changes within a version.

Both. POST /v1/parse returns a job ID immediately. Poll GET /v1/jobs/{id} or register a webhook URL on the request. You can pass mode=sync as a form field to block on the response; uploads of 10 MB or more automatically continue asynchronously.

Do you store my CAD files?

Originals are stored encrypted and accessible only via signed URLs. Result retention depends on your plan: 24 hours on Free, 7 days on Starter, 14 days on Growth, 30 days on Pro and Business, and custom on Enterprise. You can issue a delete via DELETE /v1/jobs/{id} or the dashboard at any time.

Failed jobs — am I billed?

No. System-side failures (parser crash, timeout, infra error) are never billed. User-caused errors that we detect early (invalid file, unsupported version, oversized) also don't bill. Only successful parse jobs count against your plan.

Enterprise plans include a private VPC deployment with the same API surface. Talk to us about volume, SLA and data residency.

Can an AI agent use CADLens directly?

Yes. CADLens runs a Model Context Protocol (MCP) server — a hosted Streamable HTTP endpoint plus a local stdio server (npm package cadlens-mcp) — exposing seven tools (parse_cad_file, get_job_status, get_job_result, get_job_image, list_jobs, delete_job, get_usage) authenticated with the same API key as the REST API. See /mcp and /docs#mcp.

How do I give my AI agent a CADLens skill prompt?

Copy-ready SKILL.md prompts are at /docs#skill-prompts — one for agents with the CADLens MCP server connected, one for agents that only have an API key and HTTP access. Drop either into .claude/skills/cadlens/SKILL.md, a Cursor rule, or a system prompt. The same skills are also published machine-readably, with SHA-256 digests, at /.well-known/agent-skills/index.json for agents that discover CADLens on their own.

Format Guide · DWF to JSON API

Parse DWF drawings into structured vector JSON — no pre-conversion required.

DWF (Design Web Format) is Autodesk's structured, read-only vector format. Submit a DWF file and receive entity geometry, layer metadata, drawing extents, and a PNG preview. DWF is a published-output format, so what you upload is what the author intended to release — no external references to resolve and no editing state to interpret.

Start free · 20 parses/mo →View documentation See example output

01 — THE PROBLEM

Published drawings arrive as DWF — not DWG.

In many AEC and manufacturing workflows, the source DWG file stays with the design team. What gets shared externally — with contractors, fabricators, clients, or document management systems — is a DWF export: a compact, read-only delivery format that preserves layers and geometry without exposing the editable source.

If your software receives DWF as the primary input — from a client portal, an email attachment, or an FTP drop — you need to parse the DWF directly. Converting it back to DWG adds complexity and round-trip fidelity risk. CADLens parses DWF natively.

02 — WHEN TO USE IT

Built for delivery-format workflows.

DWF parsing is the right choice in these scenarios:

Construction document management — parse published drawing sets (issued-for-construction DWFs) to extract layer names, entity counts, and drawing extents for a document index.
Fabrication intake — accept DWF files from architects and engineers as the authoritative delivery format, extract geometry for pricing or scheduling.
Digital archive systems — ingest legacy DWF archives, extract metadata and render PNG thumbnails at scale without installing Autodesk software.
Compliance and QA tools — compare layer structure and entity distribution across a set of published drawings programmatically.

03 — API WORKFLOW

Submit, poll, retrieve.

Authentication is an API key in the Authorization: Bearer header. The base URL is https://api.cadlens.co/v1.

Step 1 — Upload the DWF file:

POST /v1/parse
Content-Type: multipart/form-data
Authorization: Bearer <api_key>

file=<your-drawing.dwf>

// Response
{ "jobId": "job_03pn..." }

Pass mode=sync as a form field for a synchronous response (uploads of 10 MB or more automatically continue asynchronously). For larger files, the job is queued and you can pass a webhook_url field to receive a callback on completion.

Step 2 — Poll for status:

GET /v1/jobs/job_03pn...
Authorization: Bearer <api_key>

// Response
{
  "jobId": "job_03pn...",
  "status": "COMPLETED",   // PENDING | PROCESSING | COMPLETED | FAILED
  "fileName": "site-plan.dwf",
  "fileSize": 192000,
  "createdAt": "2024-10-14T14:00:00Z",
  "completedAt": "2024-10-14T14:00:05Z"
}

Step 3 — Retrieve the result and preview:

GET /v1/jobs/job_03pn.../result   // vector JSON
GET /v1/jobs/job_03pn.../image    // signed PNG URL

04 — EXAMPLE OUTPUT

What a DWF parse returns.

The result schema is versioned at 2.0.0. A typical DWF result for a published site plan:

{
  "jobId": "job_03pn...",
  "status": "COMPLETED",
  "file": { "name": "site-plan.dwf", "format": "DWF", "version": "6.01", "units": "m" },
  "summary": { "totalSheets": 1, "totalEntities": 124, "totalLayers": 4, "truncated": false },
  "sheets": [{
    "name": "Model", "index": 0, "entityCount": 124, "layerCount": 4,
    "layers": [
      { "name": "SITE-BOUNDARY", "colorHex": "#ffffff", "entityCount": 1  },
      { "name": "BUILDINGS",     "colorHex": "#808080", "entityCount": 24 },
      { "name": "ROADS",         "colorHex": "#ffcc00", "entityCount": 38 },
      { "name": "ANNOTATIONS",   "colorHex": "#00ff00", "entityCount": 61 }
    ],
    "entities": [
      {
        "id": "4D1",
        "handle": "4D1",
        "type": "POLYLINE",
        "category": "Geometry",
        "layer": "SITE-BOUNDARY",
        "geometry": {
          "closed": true,
          "vertices": [
            { "x": 0,   "y": 0  },
            { "x": 120, "y": 0  },
            { "x": 120, "y": 80 },
            { "x": 0,   "y": 80 }
          ]
        },
        "metrics": { "length": 400, "area": 9600, "perimeter": 400, "vertexCount": 4 }
      }
    ]
  }],
  "imageUrl": "https://cdn.cadlens.co/results/job_03pn.../preview.png?...",
  "imageUrls": ["https://cdn.cadlens.co/results/job_03pn.../preview.png?..."]
}

05 — LIMITATIONS

Fair-use and known constraints.

DWFx (beta): the DWFx variant (Open Packaging Convention format) is supported in beta. Use standard DWF for production workloads.
File size: 10 MB on the free plan; 25 MB–250 MB depending on your paid plan (1 GB on Enterprise).
Entity count: up to approximately 50,000 entities per drawing.
Processing time: up to 30 seconds on standard plans. DWF is converted to an intermediate DXF before parsing, as DWG and DGN are.
Multi-sheet DWF: when a DWF contains multiple sheets, CADLens currently parses the first model-space sheet. Multi-sheet support is on the roadmap.
Embedded raster content: raster images embedded in a DWF are not extracted; only vector entities are returned.

06 — FAQ

Common questions.

DWF (Design Web Format) is a compact, read-only vector format developed by Autodesk for sharing and publishing design data. It preserves layer structure, geometry, and metadata without exposing editable source geometry, making it common in construction, manufacturing, and document workflows.

DWF is published output rather than an editing format: external references are already resolved and the layer structure is fixed at publish time, so what you upload is what the author released. It is accepted directly — you do not have to convert it back to DWG or DXF first. Internally it is converted to an intermediate DXF before parsing, the same path DWG takes.

Standard DWF files are supported in stable production mode. DWFx (the Open Packaging Convention variant) is currently in beta. Submit standard DWF for production workloads.

Yes. DWF preserves the original layer structure from the source drawing. Each sheet in the result (sheets[].layers) contains each layer name, its color, and the count of entities on that layer.

If you already have the DWG and your workflow allows it, DXF export may be the most direct path. DWF is the best choice when the original source file is not available — for example, when receiving deliverables from a contractor or architect who provides DWF as the official published format.

No. Only successful parses count toward your monthly quota. A job that ends in FAILED status is never billed.

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