Cornerstone PM™ is the modern, AI-native alternative to Constellation HomeBuilder Systems' MarkSystems and its successor NX, built for small-to-mid home builders. Same core scope  options rules engine, sales pipeline, purchasing, scheduling, vendor portal, warranty  plus native AI agents (Foreman AI on Pro $499/mo), 37+ named webhook events (Pro+), and a public REST API (Pro+ $599/mo). Pricing published online from $149/mo. No Constellation services engagement required.
Side-by-side for small-to-mid home builders.
| Feature | Cornerstone PM™ | MarkSystems |
|---|---|---|
Public, transparent pricing Cornerstone publishes every tier on the website. MarkSystems / NX requires a Constellation sales consultation to learn what it costs. Hidden pricing is itself a feature gap when you're trying to evaluate options. | $149 / $299 / $499 / $599  listed | Hidden  consult-only |
Sign up today (no sales call required) Cornerstone is self-serve  pick a plan, sign up, you're in tonight. Constellation gates access behind 'Request a Demo' + a 1-888 sales line. | ||
Implementation cost MarkSystems / NX is sold with 'dedicated support from implementation to daily use'  that's a paid services engagement on top of license fees. Cornerstone has zero implementation cost on every tier. | $0 | Enterprise implementation engagement |
Time to operational AI Migration Wizard + 23 import endpoints. Drop your exports in, AI auto-detects column mapping, you're operational the same afternoon. NX implementations are enterprise data projects run by Constellation's services team. | Hours | Months |
Built for small-to-mid home builders (5–200 homes/yr) MarkSystems / NX is built for the full spectrum of homebuilders from 'emerging builders to established leaders'  but the implementation cost and contract structure mean small-to-mid builders rarely make it past the demo. Cornerstone is built specifically for the 5–200 homes/yr builder. | ||
Native AI agents (Foreman AI + Blueprint AI) Cornerstone Pro ($499/mo) ships Foreman AI's 396+ skills that read AND write data plus Blueprint AI's 60-second floor-plan takeoffs as part of the core platform. Constellation's Stella AI is a separate product in their lineup, not included with the MarkSystems / NX license  different category for builders evaluating real AI capability per dollar. | Stella AI (separate add-on) | |
AI image search, vision & anti-bot web scraping Foreman searches product images, hosts them on CDN, reads Home Depot/Ferguson product pages with AI-powered web scraping. Plus: paste or drag-drop any screenshot from inside the app and Foreman reads it with AI vision and acts on it. Cornerstone Pro feature. | ||
37+ named webhook events (catalog growing) Cornerstone Pro+ ($599/mo): 37+ named events and counting  typed payloads, HMAC signatures, delivery logs, auto-retry. NX advertises 'modern APIs' but no public webhook catalog. | Limited | |
AI Migration Wizard (one-click CRM import) AI auto-detects MarkSystems / NX export column mapping and runs 23 import endpoints. ~$0.01 per migration. Constellation migrations go through their services team as a paid implementation engagement. | ||
Built-in accounting / GL NX ships full ERP-grade accounting  GL, AP/AR, retainage, audit trails, financial reporting. That's a legitimate strength for 300+ homes/yr builders who want operations and accounting on one stack. Cornerstone is built for the 5–200 homes/yr builder who already runs QuickBooks or similar  we integrate with your existing accounting via our public REST API instead. | Integrate via API (QuickBooks, etc.) | |
Land development scheduling & tracking Both platforms handle land development scheduling  clearing, grading, utilities, paving  and multi-phase community tracking once you own the dirt. Cornerstone builds it into the same scheduling engine that runs the rest of the build. | ||
Land acquisition lead tracking (ownership history, bonds) NX (and Constellation's separate LandDev product) tracks land acquisition activities, ownership history, and bonds. Cornerstone handles land-dev scheduling and tracking today, but the dirt-pursuit CRM piece (parcels, ownership, bonds) is on the roadmap, not in the product yet. Honest about it. | Not yet | |
Property management module (rentals) NX includes property management  applications, move-ins, rent billing, regulatory compliance. Useful if you operate rentals. Cornerstone is purely home build PM, not property management. | ||
Options rules engine Both ship structural and design option rules with dependencies, incompatibilities, and price rollups. | ||
Designer Packages (64 curated by an interior designer, 7 categories) Cornerstone Builder+: 64 designer packages curated by an actual interior designer (the same playbook K. Hovnanian Homes uses). Buyers pick a package; all category options auto-lock. NX has options selection but no curated package library. | ||
Triple QR ecosystem (vendor + PM + buyer, no app install) Three QR codes for three audiences, no app required: (1) vendor jobsite check-in captures GPS + timestamp + weather + photo upload automatically, (2) PM/internal-builder check-in feeds GPS-validated timesheets so you can prove who was actually on-site, (3) sales model home QR for walk-in buyer lead capture. NX ships none of these. | ||
Vendor Activity Map (Google Maps, real-time) Live Google Maps view of every vendor check-in across every community, 30-second refresh. See exactly who's on which jobsite right now. NX has no equivalent. | ||
Vendor portal access NX gives vendors a login. Cornerstone sends vendors a tokenized magic link  they bid, accept schedule changes, and confirm tasks straight from email with no account, no password, no app install. Adoption is dramatically higher when subs don't have to manage another login. | Tokenized magic links  zero login | Login-required vendor portal |
Flexible PO generation (4 patterns, mix on same job) Cornerstone gives you four PO patterns: (1) all POs at job start, (2) partial deposit POs from earlier pipeline tasks (permit pull, contract sign, foundation pour), (3) full PO auto-generated when a task is marked complete, or (4) configurable per task / scope / community. Mix all four on the same job. NX generates POs from bid sheets and BOM templates  capable but enterprise-rigid. | Standard | |
Homeowner portal (realtime sync + photos + messaging + ZIP export) Cornerstone includes the buyer portal at every tier ($149+)  real-time sync with construction schedule, milestone photos, messaging, one-click ZIP export of all job photos. Constellation sells Homeowner Central as a separate product in their ecosystem. | Separate product (Homeowner Central) | |
Modern web + mobile UI Both ship modern web + mobile. NX's mobile app is field-facing for schedule and service requests; Cornerstone is mobile-first across the whole app, including buyer portal and sales workflows. | ||
Public REST API (150+ API endpoints) Cornerstone Pro+: 150+ REST API endpoints with public docs. NX advertises 'modern APIs' for integration but no public endpoint catalog  most integrations go through Constellation services. | Limited public docs | |
BYOA (Bring Your Own Agent) Cornerstone Pro+ ($599/mo): connect Claude or ChatGPT to your live data via REST + webhooks. NX is a closed ecosystem with Stella AI as the sanctioned agent. | ||
Take your data with you anytime  no lock-in Your data is YOURS. Full database export to CSV or JSON anytime, one click, $0, no fees, no waiting on a support ticket. Nightly auto-backups retained 7 days for instant rollback. Constellation data extraction goes through their services team. | ||
Per-user fees Cornerstone: flat tier pricing, no per-seat scaling, up to 30 users (60 on Pro+). NX user licensing is enterprise-contract  typically per-user / per-module / per-community. | Up to 30 users (60 on Pro+), every tier | Enterprise contract |
Construction scheduling Both ship full scheduling. Cornerstone adds auto-cascading 3-tier dependencies, 17 pre-built templates, critical path highlighting, and permit gates out of the box. | ||
Pricing model NX: enterprise contract, consult-led pricing, paid implementation, separate licenses for products like LandDev, Homeowner Central, BuilderMetrix, and Stella AI. Cornerstone: flat monthly, every feature included at the tier, self-serve onboarding. | Flat  published online | Enterprise quote + implementation + per-module licensing |
Cornerstone tiers (flat  up to 30 users • 60 on Pro+) Starter ($149): scheduling, permits, homeowner portal. Builder ($299): adds sales pipeline, purchasing, design center with options engine and designer packages. Pro ($499): adds Foreman AI + Blueprint AI. Pro+ ($599): adds REST API, BYOA, 37+ named webhook events, 7-wave bidding. | $149 / $299 / $499 / $599 |  |
Pricing and feature availability reflect publicly available information as of 2026. Verify current pricing and capabilities directly with each vendor. MarkSystems® is a trademark of its respective owner; Cornerstone PM™ is not affiliated with or endorsed by MarkSystems.
Constellation NX (the modern successor to MarkSystems) is built for top-100 production builders with implementation budgets, services contracts, and a Constellation consultant on retainer. Cornerstone delivers the same core homebuilder capabilities  options engine, sales pipeline, purchasing, vendor portal, scheduling  for the 5–200 homes/yr builder. Flat published pricing, self-serve onboarding, no implementation engagement.
Constellation sells Stella AI as a separate product on top of NX. Cornerstone bakes Foreman AI (396+ skills) and Blueprint AI directly into Pro ($499/mo)  same monthly fee, no add-on contract, no separate implementation. AI is the platform, not an upsell.
150+ REST API endpoints, 37+ named webhook events (catalog growing), HMAC signatures, public docs. Wire Twilio, Bland, Retell, or your own agents to our webhooks. NX integrations are enterprise services engagements.
Export your MarkSystems / NX data, drag the files into our wizard, and AI auto-maps every column across vendors, homes, communities, design options, scopes, and budgets. Dry-run before you commit. ~$0.01 per migration  we absorb it. No Constellation services engagement required.
Costs about $0.01 per migration in AI — we absorb it. You pay zero.
Common questions about switching to Cornerstone PMâ„¢ from MarkSystems, NX, or NEWSTAR.
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