Cornerstone handles everything else.
REST API endpoints that let any AI agent automate the entire subcontractor bidding pipeline — from cold call to signed contract. No manual data entry. No other homebuilder platform does this.
Bearer token auth. JSON responses. Standard REST. Plug in any agent — custom-built, third-party, or Cornerstone's own Foreman AI.
/api/ext/vendorsCreate a subcontractor or supplier in Cornerstone programmatically. Your AI agent collects contact info from a phone call and writes it directly to the database.
{
"name": "ABC Plumbing LLC",
"email": "bids@abcplumbing.com",
"phone": "555-0192",
"scopes": ["Plumbing", "HVAC"],
"contacts": [{ "name": "Mike", "role": "Estimator" }]
}/api/ext/bids/requestSend a scoped bid request to one or more vendors with plans, specs, and deadline. Triggers automatic 7-day follow-up reminders.
{
"vendorIds": ["v_abc123", "v_def456"],
"scope": "Plumbing",
"dueDate": "2026-05-15",
"plans": ["https://...floorplan.pdf"],
"notes": "Rough-in only, 3 units"
}/api/ext/bidsQuery all bids by status, scope, or vendor. Your agent monitors responses in real time and notifies you the moment a bid comes in.
// GET /api/ext/bids?scope=Plumbing&status=received
{
"bids": [
{
"vendor": "ABC Plumbing LLC",
"total": 18400,
"status": "received",
"lineItems": [...]
}
]
}Different permissions for different integrations. Read-only, write-only, or full access.
Custom-built, third-party, or Cornerstone's Foreman AI. If it can make an HTTP request, it works.
Get notified the moment a bid arrives, a vendor responds, or a status changes.
Pro+ users get access to Foreman AI's complete skill definitions — the actual tool schemas that make any AI agent instantly fluent in construction workflows. One endpoint. 47 skills. Ready to drop into any agent framework.
Think of it as a knowledge file for your AI. Point any agent at our developer docs and it instantly understands every endpoint, every workflow, every skill in Cornerstone — before you've even signed up.
app.cornerstonepm.ai/developers →/api/ext/skillsReturns all 47 Foreman AI skill definitions in your choice of format. Drop them directly into any Claude, GPT-4, or LangChain agent to give it full construction intelligence in seconds.
Format options
?format=anthropic?format=openai?format=openapi47 skills across 7 domains
Hover a category to see included skills
Any AI agent — Claude, GPT-4, a custom LangChain bot — becomes a construction expert the moment you load the skill pack.
The endpoint reflects Foreman's live skill set. When we ship new skills, your agent gets them automatically. No version management.
Anthropic tools, OpenAI functions, or raw OpenAPI 3.1. Use whatever your stack already speaks.
Your AI agent runs all 7 waves automatically. Cornerstone tracks every interaction, every bid, every vendor — in real time.
Your agent dials subcontractors, collects contact info, leaves voicemails, and sends texts. Every interaction recorded with full transcript.
Automated email campaign to all vendors with confirmed email addresses. Includes project specs, plans, and bid deadline.
AI reads incoming emails, extracts vendor data, and creates vendor records in Cornerstone via the REST API. Zero manual data entry.
All verified vendors receive a scoped bid request with plans attached. Triggered programmatically or from inside Cornerstone.
No response after 7 days? The system follows up automatically — by email, text, or another call — without anyone lifting a finger.
Bids flow into Cornerstone with line items. Side-by-side comparison across all vendors. Owner gets real-time notifications as bids arrive.
Winning vendors get a magic link to self-register into Cornerstone — scheduling, POs, invoices, and document requirements handled automatically.
Cornerstone's own 47-skill construction agent. Already wired to the API. No setup required.
Learn moreBuild your own agent with any framework (LangChain, AutoGen, Claude, GPT-4) and connect to our REST API with a Bearer token.
Pre-built integrations with popular AI platforms. If it can make an HTTP call, it can talk to Cornerstone.
If an AI agent can make a phone call or read an email, it can now act on your Cornerstone data. Here's what builders are already building.
An AI agent reads your existing Buildertrend, JobTread, or Excel data and migrates it into Cornerstone automatically. No manual re-entry, no implementation consultant, no $25k fee. You own the process.
Bridge Cornerstone and QuickBooks, Sage, or your accounting system of choice. POs, invoices, and job costs flow both ways automatically — no double entry, no CSV exports.
Your voice agent calls roofing companies, electricians, framers — gets their email and contact info, adds them as vendors in Cornerstone automatically. 200 vendors contacted in an afternoon.
An email-scanning agent reads incoming vendor emails, extracts bid data, and logs everything in Cornerstone — no manual entry, no missed bids. Your inbox becomes an automated data pipeline.
Agent monitors your Cornerstone task completions and generates POs automatically when a scope is finished. Schedule drives purchasing — you never have to manually create a PO again.
A voice agent calls the framer who hasn't confirmed their schedule date. Records the outcome. Updates the task status. Your schedule enforces itself.
Beta limited to 100 builders · No credit card required
Stripe made it possible to build a payment system in a weekend. We're doing the same for subcontractor bidding.
Request Early Access →