REST API

API Documentation

Access Toronto zoning data programmatically. Look up any address and get back effective standards, development potential, GIS layers, and more — the same data that powers the web app.

Base URL

https://api.torontozoning.com

All endpoints accept and return JSON. No authentication is required for public endpoints.

Quick Start

Look up zoning data for any Toronto address with a single API call:

curl -X POST https://api.torontozoning.com/lookup \
  -H "Content-Type: application/json" \
  -d '{"address": "226 Viewmount Ave"}'

POST

/lookup

The primary endpoint. Returns a complete zoning profile for a Toronto address including effective standards, development potential, GIS layers, and constraints.

Request Body

`address`required	string	Toronto street address (e.g. "226 Viewmount Ave")
`include_parcel`	boolean	Include property boundary geometry. Default: true
`include_nearby`	boolean	Include nearby development activity. Default: false
`include_policy`	boolean	Include policy conformity analysis. Default: false
`lot_area_sqm`	number	Override lot area (useful for assembly scenarios)
`lot_frontage_m`	number	Override lot frontage
`lot_depth_m`	number	Override lot depth
`proposed_use`	string	Proposed use to analyze (e.g. "restaurant", "dwelling unit")

Response

{
  "address": "226 Viewmount Ave",
  "coordinates": { "latitude": 43.65633, "longitude": -79.43123 },
  "effective_standards": {
    "zone_code": "RD",
    "zone_string": "RD (f12.0; a325) (x123)",
    "height": { "effective_m": 10, "effective_storeys": 3, "effective_source": "base_zone" },
    "fsi": { "effective_total": 0.6, "effective_source": "base_zone" },
    "lot_coverage": { "effective_pct": 35, "effective_source": "base_zone" },
    "setbacks": { "effective_front_m": 6.0, "effective_rear_m": 7.5, "effective_side_m": 1.2 },
    "exception": { "exception_number": 123 },
    "heritage_impact": { "has_heritage": false },
    "natural_hazards": { "has_hazards": false }
  },
  "development_potential": {
    "lot": { "area_sqm": 325, "frontage_m": 12.0, "depth_m": 27.1 },
    "max_gfa": { "sqm": 195, "limiting_factor": "lot_coverage" },
    "height": { "max_m": 10, "max_storeys": 3 },
    "setbacks": { "buildable_area_sqm": 195 },
    "confidence": { "overall_score": 85, "overall_confidence": "high", "grade": "A" }
  },
  "layers": {
    "zoning_area": [ ... ],
    "heritage_register": [ ... ],
    "major_transit_station_area": [ ... ]
  },
  "policy_conformity": { ... },
  "zoning_statistics_table": { ... }
}

POST

/suggest

Address autocomplete. Returns matching Toronto addresses for typeahead search.

Request Body

`text`required	string	Partial address text (minimum 3 characters)
`max_suggestions`	number	Maximum results to return. Default: 8

curl -X POST https://api.torontozoning.com/suggest \
  -H "Content-Type: application/json" \
  -d '{"text": "226 view"}'

// Response
{
  "suggestions": [
    "226 Viewmount Ave",
    "226 View North Rd",
    ...
  ]
}

POST

/lookup/batch

Look up multiple addresses in a single request (up to 50).

Request Body

`addresses`required	string[]	Array of Toronto addresses (max 50)
`include_parcel`	boolean	Include property boundaries. Default: true
`include_nearby`	boolean	Include nearby activity. Default: false
`max_concurrency`	number	Max parallel lookups. Default: 10

curl -X POST https://api.torontozoning.com/lookup/batch \
  -H "Content-Type: application/json" \
  -d '{
    "addresses": [
      "226 Viewmount Ave",
      "100 Queen St W",
      "1 Yonge St"
    ]
  }'

// Response
{
  "results": [ ... ],
  "total": 3,
  "success_count": 3,
  "error_count": 0,
  "total_ms": 2340
}

POST

/analyze-use

Check if a specific use is permitted in a zone. Returns conditions, parking requirements, and by-law references.

Request Body

`use`required	string	The use to analyze (e.g. "restaurant", "dwelling unit", "retail store")
`report`required	object	Full zoning report object (from /lookup response)

// First, get a zoning report
const report = await fetch("https://api.torontozoning.com/lookup", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ address: "100 Queen St W" })
}).then(r => r.json());

// Then check use eligibility
const analysis = await fetch("https://api.torontozoning.com/analyze-use", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    use: "restaurant",
    report: report
  })
}).then(r => r.json());

POST

/analyze-use/list

List all available uses that can be analyzed for a given zone family.

curl -X POST https://api.torontozoning.com/analyze-use/list \
  -H "Content-Type: application/json" \
  -d '{"zone_family": "CR"}'

// Response
{
  "uses": ["amusement arcade", "art gallery", "artist studio", "bar", ...]
}

POST

/reference

Fetch by-law text, exception details, SASP policies, or zone information.

Request Body

`type`required	string	"bylaw-section", "exception", "sasp", "op-designation", or "zone-info"
`id`required	string	Section ID, exception number, or policy reference
`zone_code`	string	Zone code for context (optional)

curl -X POST https://api.torontozoning.com/reference \
  -H "Content-Type: application/json" \
  -d '{"type": "exception", "id": "123"}'

// Response
{
  "found": true,
  "title": "Exception 123",
  "text": "Despite regulation 10.20.40.10(1), the maximum ...",
  "data": { ... }
}

GET

/map/metadata

List all available GIS layers with styling information. Useful for building map UIs.

curl https://api.torontozoning.com/map/metadata

// Response
{
  "layers": [
    {
      "key": "zoning_area",
      "label": "Zoning Areas",
      "color": "#3b82f6",
      "weight": 2,
      "fillOpacity": 0.15,
      "group": "Zoning"
    },
    ...
  ]
}

GET

/map/layers/{layer_key}

Get GeoJSON features for a specific GIS layer within a radius of a coordinate.

Query Parameters

`lon`required	number	Longitude
`lat`required	number	Latitude
`radius`	number	Radius in degrees. Default: 0.005

curl "https://api.torontozoning.com/map/layers/zoning_area?lon=-79.431&lat=43.656&radius=0.005"

// Response: GeoJSON FeatureCollection
{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "geometry": { "type": "Polygon", "coordinates": [...] },
      "properties": {
        "ZONE_CODE": "RD",
        "ZONE_LABEL": "Residential Detached",
        ...
      }
    }
  ]
}

GET

/nearby-activity

Nearby development activity — building permits, Committee of Adjustment applications, and rezoning applications.

Query Parameters

`lon`required	number	Longitude
`lat`required	number	Latitude
`radius`	number	Radius in metres. Default: 500
`limit`	number	Max events to return. Default: 50
`event_type`	string	Filter by type: "permit", "coa", "rezoning"

curl "https://api.torontozoning.com/nearby-activity?lon=-79.431&lat=43.656&radius=500"

// Response
{
  "center": { "lon": -79.431, "lat": 43.656 },
  "radius_m": 500,
  "total": 12,
  "by_type": { "permit": 8, "coa": 3, "rezoning": 1 },
  "events": [ ... ]
}

POST

/dev-charges/calculate

Estimate development charges for a proposed project based on unit counts and building type.

Request Body

`units_bachelor`	number	Number of bachelor units
`units_2plus`	number	Number of 2+ bedroom units
`units_lowrise`	number	Number of low-rise units
`units_single_semi`	number	Number of single/semi units
`non_residential_gfa_sqm`	number	Non-residential GFA in m²
`is_purpose_built_rental`	boolean	Is this purpose-built rental? (affects exemptions)

curl -X POST https://api.torontozoning.com/dev-charges/calculate \
  -H "Content-Type: application/json" \
  -d '{
    "units_2plus": 6,
    "is_purpose_built_rental": false
  }'

// Response
{
  "city_dc": { "items": [...], "subtotal": 142800 },
  "education_dc": { "items": [...], "subtotal": 18600 },
  "go_transit_dc": { ... },
  "exemptions_applied": [],
  "total_estimated": 168420
}

POST

/chat

AI-powered zoning assistant. Ask natural language questions about Toronto zoning, optionally scoped to a specific address.

Request Body

`question`required	string	Your zoning question in natural language
`address`	string	Optional address for property-specific context
`conversation_id`	string	For multi-turn conversations

curl -X POST https://api.torontozoning.com/chat \
  -H "Content-Type: application/json" \
  -d '{
    "question": "Can I build a laneway suite at this address?",
    "address": "226 Viewmount Ave"
  }'

// Response
{
  "answer": "Based on the zoning for 226 Viewmount Ave (RD zone) ...",
  "sources": ["Chapter 150.8", "Exception 123"],
  "property_context": { ... },
  "status": "ok"
}

Usage Notes

The API is free during the beta period. Rate limits may be introduced in the future.
Responses are cached for up to 1 hour. Identical requests will return cached results.
Data is sourced from the City of Toronto Open Data Portal. This is not legal advice.
Batch requests are limited to 50 addresses per call.

Ready to integrate?

Start making API calls now — no signup or API key required during beta.

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