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Umwelt vs Craft Quantities

A side-by-side comparison built from both listings. Blank cells mean the company has not given that detail; we never guess.

Umwelt compared with Craft Quantities
DetailUmwelt logo UmweltCraft Quantities logo Craft Quantities
What it doesAn epistemic state engine that tracks what each character knows, and how they learned it Free JSON API for construction calculators with test vectors and building codes
StageNot given Not given
FoundedNot given Not given
Based inNot given Not given
Pricing modelOpen source Open source
PricingAGPL-3.0-only open source license. Commercial license available for closed-source products, services and hosted APIs. Free Play Exception covers free games, mods, interactive fiction and tabletop tools (excluding games with price, in-game purchases, ads, paid content or early access). Free under CC BY 4.0 licence
Key features
  • Tracks what each character knows and how they learned it
  • Prevents AI models from leaking story information or twists
  • Records confirmed history that is never deleted
  • Single portable .umw file for entire world state
  • Works across TypeScript, .NET, CLI and any language via JSON protocol
  • Query from any character's point of view at any moment in time
  • Performance of 55-65 microseconds per query with half a million holdings
  • Free Play Exception for non-commercial games and tabletop tools
  • 1,173 construction calculators with full inputs and test vectors
  • 3,485 published test vectors for validation
  • No authentication key or rate limits required
  • Citations to building standards with section numbers
  • Executable API for running calculations on request
  • MCP server integration for AI assistants
  • 79 job takeoffs with calculator sequences
  • Cross-market glossary in US, Canadian, UK and Australian usage
  • Corrections ledger tracking confirmed errors
  • Unit conversion with exact statutory factors
What makes it different
  • Separates world state from character knowledge to prevent narrative leakage
  • Guarantees written down with conformance testing across all clients
  • Idempotent writes ensure consistency across retries
  • Works without AI or can control what AI models are allowed to know
  • Open source with commercial licensing option for closed-source products
  • No API key required with no rate limits or quotas
  • CC BY 4.0 licence allows commercial use and redistribution
  • Every calculation cited to specific building code sections
  • Pinned test cases prevent silent changes to published figures
  • Complete accessibility with CORS support for browser use
Free planNot given Not given
Open sourceNot given Not given
PlatformsNot given Not given
Public APINot given Not given
Community votes00
DR (Domain Rating by Ahrefs)Not checked yet no change since last checkNot checked yet
Trust Flow (Majestic)40
Citation Flow (Majestic)1226
Referring domains (Majestic)129

5 details filled in for both companies.

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