STACK

STACK Construction Technologies makes cloud-based preconstruction software for on-screen takeoff and estimating used by contractors across most trades. STACK does expose a real, documented REST API (v2), but access is gated - you must be a STACK customer on an API-Enabled Subscription (or an approved partner) to obtain credentials. Authentication is OAuth 2.0, offered as two-legged (client-credentials, server-to-server) and three-legged (authorization-code, on behalf of a user) flows. Tokens are issued by a per-tenant authorization server (base pattern https://{server}/api/v2). The full endpoint reference sits behind an access request; the API surface catalogued here is modeled from STACK's public developer overview, authentication guide, and tutorials - it is not sourced from an official machine-readable OpenAPI document.

STACK publishes 6 APIs on the APIs.io network, including Projects API, Plans & Files API, Takeoffs API, and 3 more. Tagged areas include Construction, Preconstruction, Takeoff, Estimating, and Construction Technology.

STACK’s developer surface includes documentation, authentication, signup flow, engineering blog, and 6 more developer resources.

🌐 Visit website 📡 Source on GitHub
34.5/100 thin ▬ flat Agent 28/100 agent aware Full breakdown ↓
scored 2026-08-05 · rubric v0.9.1
AccessFreemiumFree trial
6 APIs
ConstructionPreconstructionTakeoffEstimatingConstruction TechnologyPartner API

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-05 · rubric v0.9.1
Composite quality — 34.5/100 · thin
Contract Quality 8.1 / 25
Developer Ergonomics 4.3 / 20
Commercial Clarity 10.5 / 20
Operational Transparency 4.1 / 13
Governance 0.0 / 12
Discoverability 7.4 / 10
Agent readiness — 28/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 0 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/stack-takeoff: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 6

Individual APIs this provider publishes, each with its own machine-readable definition.

STACK Projects API

Create and update projects and organize their contents in folders - the top-level container that takeoffs, plans, and estimates hang off of. Modeled from STACK's developer tutor...

STACK Plans & Files API

Upload plan sets and supporting documents into project folders, read file metadata, update file properties, and download plans. Modeled from STACK's developer tutorials (Folders...

STACK Takeoffs API

Create takeoffs on a project, list a takeoff's pages, set page scale, and retrieve measured quantities. On-screen takeoff is STACK's core workflow. Modeled from STACK's develope...

STACK Estimates API

Create, update, and retrieve estimate proposals - turning takeoff quantities into priced line items and a bid. Modeled from STACK's developer tutorials (EstimateProposals endpoi...

STACK Items & Assemblies API

Manage items and assemblies attached to takeoffs and retrieve their quantities and costs, so partner tools can pull takeoff/estimating data into invoices, purchase orders, or a ...

STACK Reference Data API

Read-only lookup endpoints for cost types, states, and countries used when constructing projects and estimates. Modeled from STACK's developer tutorials (CostTypes, States, Coun...

Pricing Plans 1

Published pricing tiers and plan structures.

Stack Takeoff Plans Pricing

4 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Stack Takeoff Rate Limits

4 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Stack Takeoff Finops

FINOPS

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Stack Takeoff Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

SignUp
SignUp

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

RateLimits
RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans
Plans
 FinOps
FinOps

Company 3

The organization behind the API

LinkedIn
LinkedIn
 Website
Website
 Blog
Blog

Source (apis.yml)

apis.yml Raw ↑ 
aid: stack-takeoff
url: https://raw.githubusercontent.com/api-evangelist/stack-takeoff/refs/heads/main/apis.yml
name: STACK
kind: company
description: STACK Construction Technologies makes cloud-based preconstruction software for on-screen takeoff and estimating
  used by contractors across most trades. STACK does expose a real, documented REST API (v2), but access is gated - you must
  be a STACK customer on an API-Enabled Subscription (or an approved partner) to obtain credentials. Authentication is OAuth
  2.0, offered as two-legged (client-credentials, server-to-server) and three-legged (authorization-code, on behalf of a user)
  flows. Tokens are issued by a per-tenant authorization server (base pattern https://{server}/api/v2). The full endpoint
  reference sits behind an access request; the API surface catalogued here is modeled from STACK's public developer overview,
  authentication guide, and tutorials - it is not sourced from an official machine-readable OpenAPI document.
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: true
  try_now: false
  public: false
  label: Freemium (free trial)
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/stack-takeoff.png
tags:
- Construction
- Preconstruction
- Takeoff
- Estimating
- Construction Technology
- Partner API
created: '2026-07-04'
modified: '2026-07-04'
specificationVersion: '0.19'
apis:
- aid: stack-takeoff:stack-takeoff-projects-api
  name: STACK Projects API
  tags:
  - Projects
  - Folders
  - Preconstruction
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.stackct.com/developers-docs/
  baseURL: https://{server}/api/v2
  properties:
  - url: https://www.stackct.com/developers-docs/
    type: Documentation
  - url: https://www.stackct.com/developers-reference/
    type: APIReference
  - url: openapi/stack-takeoff-openapi.yml
    type: OpenAPI
  description: Create and update projects and organize their contents in folders - the top-level container that takeoffs,
    plans, and estimates hang off of. Modeled from STACK's developer tutorials (POST/PUT /Projects, project Folders CRUD).
- aid: stack-takeoff:stack-takeoff-plans-files-api
  name: STACK Plans & Files API
  tags:
  - Plans
  - Files
  - Documents
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.stackct.com/developers-docs/
  baseURL: https://{server}/api/v2
  properties:
  - url: https://www.stackct.com/developers-docs/
    type: Documentation
  - url: https://www.stackct.com/developers-docs-tutorials/
    type: Documentation
  - url: openapi/stack-takeoff-openapi.yml
    type: OpenAPI
  description: Upload plan sets and supporting documents into project folders, read file metadata, update file properties,
    and download plans. Modeled from STACK's developer tutorials (Folders/Files endpoints).
- aid: stack-takeoff:stack-takeoff-takeoffs-api
  name: STACK Takeoffs API
  tags:
  - Takeoff
  - Pages
  - Quantities
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.stackct.com/developers-docs/
  baseURL: https://{server}/api/v2
  properties:
  - url: https://www.stackct.com/developers-docs/
    type: Documentation
  - url: https://www.stackct.com/developers-docs-tutorials/
    type: Documentation
  - url: openapi/stack-takeoff-openapi.yml
    type: OpenAPI
  description: Create takeoffs on a project, list a takeoff's pages, set page scale, and retrieve measured quantities. On-screen
    takeoff is STACK's core workflow. Modeled from STACK's developer tutorials (CreateTakeoff, Takeoffs Pages, Scale).
- aid: stack-takeoff:stack-takeoff-estimates-api
  name: STACK Estimates API
  tags:
  - Estimating
  - Proposals
  - Costs
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.stackct.com/developers-docs/
  baseURL: https://{server}/api/v2
  properties:
  - url: https://www.stackct.com/developers-docs/
    type: Documentation
  - url: https://www.stackct.com/developers-docs-tutorials/
    type: Documentation
  - url: openapi/stack-takeoff-openapi.yml
    type: OpenAPI
  description: Create, update, and retrieve estimate proposals - turning takeoff quantities into priced line items and a bid.
    Modeled from STACK's developer tutorials (EstimateProposals endpoints).
- aid: stack-takeoff:stack-takeoff-items-assemblies-api
  name: STACK Items & Assemblies API
  tags:
  - Items
  - Assemblies
  - Cost Data
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.stackct.com/developers-docs/
  baseURL: https://{server}/api/v2
  properties:
  - url: https://www.stackct.com/developers-docs/
    type: Documentation
  - url: openapi/stack-takeoff-openapi.yml
    type: OpenAPI
  description: Manage items and assemblies attached to takeoffs and retrieve their quantities and costs, so partner tools
    can pull takeoff/estimating data into invoices, purchase orders, or a separate estimating system. Modeled from STACK's
    developer overview description of core capabilities.
- aid: stack-takeoff:stack-takeoff-reference-data-api
  name: STACK Reference Data API
  tags:
  - Reference Data
  - Cost Types
  - Lookups
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.stackct.com/developers-docs/
  baseURL: https://{server}/api/v2
  properties:
  - url: https://www.stackct.com/developers-docs-tutorials/
    type: Documentation
  - url: openapi/stack-takeoff-openapi.yml
    type: OpenAPI
  description: Read-only lookup endpoints for cost types, states, and countries used when constructing projects and estimates.
    Modeled from STACK's developer tutorials (CostTypes, States, Countries).
common:
- type: DomainSecurity
  url: security/stack-takeoff-domain-security.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/stack-construction-technologies
- type: Website
  url: https://www.stackct.com/
- type: Documentation
  url: https://www.stackct.com/developers-docs/
- type: Authentication
  url: https://www.stackct.com/developers-docs-authentication/
- type: SignUp
  url: https://www.stackct.com/developers/
- type: Plans
  url: plans/stack-takeoff-plans-pricing.yml
- type: RateLimits
  url: rate-limits/stack-takeoff-rate-limits.yml
- type: FinOps
  url: finops/stack-takeoff-finops.yml
- url: https://www.stackct.com/blog/
  type: Blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com