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Viaduct vs act101

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

Viaduct compared with act101
DetailViaduct logo Viaductact101 logo act101
What it doesFree C4 modeling tool with an MCP server for software teams to share architecture context with AI development tools Quality infrastructure for AI-written code with deterministic refactoring and a merge gate
StageNot given Startup
FoundedNot given 2026
Based inLT US
Pricing modelFreemium Freemium
PricingBrowser: Free with account. Desktop: €10 a month after 7-day free trial, one licence covers 3 machines. Enterprise: custom pricing. Builder Edition: Free forever for personal, non-commercial, and open-source use. Engineering Edition: $29/month or $299/year (save 14%). Architecture Edition: $59/month or $599/year (save 15%). Elite Edition: $99/month or $999/year (save 16%). Enterprise: Custom pricing, contact sales. All editions
Key features
  • System context, container, component, and code diagrams
  • Live collaboration on models
  • MCP server for AI coding agents
  • Change sets for scoped agent work
  • Organization SSO
  • JSON import and export
  • OpenAPI contract export
  • Desktop app for macOS, Windows, Linux
  • AI assistant for model descriptions
  • Installable PWA
  • 182 AST-aware refactor operations for code transformation
  • 42 codebase analyzers for code analysis
  • Support for 163 programming grammars
  • Deterministic merge gate with signed receipts
  • MCP server and CLI interfaces
  • Cross-file import updates and automatic checkpointing
  • 10 cross-language porting operations
  • Instant undo for all operations
  • ~88% token savings on query operations
  • Native binary with zero dependencies and no supply chain risk
What makes it different
  • Model elements exist once and appear on every level they belong to
  • Endpoints are real OpenAPI documents, not diagram labels
  • Desktop app keeps all data local and offline-capable
  • Free browser version with no paywall or feature limits
  • AI agents read and write architecture through MCP
  • Deterministic verdicts and signed receipts for every code change ensure reproducible quality gates
  • Built by engineer with decades of production experience in correctness-critical domains
Community votes00
DR (Domain Rating by Ahrefs)20 no change since last check27 no change since last check
Trust Flow (Majestic)108
Citation Flow (Majestic)2831
Referring domains (Majestic)74182

6 details filled in for both companies.

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