Partner API

Use the Partner API to pull carbon footprint emissions data for your products into your own systems — including total emissions, a link to the full results page, and a shareable PDF report.

The Zilch API is only included on Starter and above plans. It will return null on the free plan.

Authentication

All requests require your secret API key passed as a header:

http

x-api-key: YOUR_API_KEY

You can find your API key in Settings → Profile inside your Zilch account. If you haven't generated one yet, click Generate API Key on that page.

Keep your API key secret. If it's ever exposed, you can rotate it from the same page — this immediately invalidates the old key.

Base URL

https://www.api.tryzilch.com

Endpoints

1. All products

Returns emissions data for every assessed product in your account.

http

GET /api/partner/emissions-totals

Rate limit: 2 requests per 24 hours.

Query parameters

Parameter	Type	Required	Description
`page`	integer	No	Page number (default: `1`)
`items_per_page`	integer	No	Results per page, max `500` (default: `100`)
`skus`	string	No	Comma-separated list of SKUs to filter by

Example — all products

bash

curl -H "x-api-key: YOUR_API_KEY" \
  "https://www.api.tryzilch.com/api/partner/emissions-totals"

Example — filter to specific SKUs

bash

curl -H "x-api-key: YOUR_API_KEY" \
  "https://www.api.tryzilch.com/api/partner/emissions-totals?skus=ABC-001,ABC-002"

Example response

json

{
  "success": true,
  "page": 1,
  "items_per_page": 100,
  "total_items": 3,
  "data": [
    {
      "product_id": "3a8f63ea-0a71-4c3e-b4c6-9a3269a6b299",
      "product_name": "Recycled Tote Bag",
      "sku": "RTB-001",
      "supplier_id": "4f6931f7-c31a-44fa-8df0-55cdc418a218",
      "total_kg_co2e": 2.41,
      "emissions_breakdown": {
        "total": 2.41,
        "materials": 1.12,
        "packaging": 0.34,
        "decoration": 0.21,
        "transport": 0.48,
        "manufacturing": 0.26
      },
      "last_calculated_at": "2026-02-15T09:34:00.000Z",
      "results_url": "https://app.tryzilch.com/results/3a8f63ea...?supplier_id=4f6931f7...",
      "pdf_url": "https://www.api.tryzilch.com/api/pdf/4f6931f7.../3a8f63ea..."
    }
  ]
}

2. Single product by SKU

Returns emissions data for one specific product, looked up by SKU.

http

GET /api/partner/emissions-by-sku

Rate limit: 1,000 requests per SKU per 24 hours.

Query parameters

Parameter	Type	Required	Description
`sku`	string	Yes	The product SKU

Example

bash

curl -H "x-api-key: YOUR_API_KEY" \
  "https://www.api.tryzilch.com/api/partner/emissions-by-sku?sku=RTB-001"

Example response

json

{
  "success": true,
  "data": {
    "sku": "RTB-001",
    "product_name": "Recycled Tote Bag",
    "total_kg_co2e": 2.41,
    "emissions_breakdown": {
      "total": 2.41,
      "materials": 1.12,
      "packaging": 0.34,
      "decoration": 0.21,
      "transport": 0.48,
      "manufacturing": 0.26
    },
    "last_calculated_at": "2026-02-15T09:34:00.000Z",
    "results_url": "https://app.tryzilch.com/results/3a8f63ea...?supplier_id=4f6931f7...",
    "pdf_url": "https://www.api.tryzilch.com/api/pdf/4f6931f7.../3a8f63ea..."
  }
}

Response fields

Field	Description
`total_kg_co2e`	Total carbon footprint in kg CO₂e
`emissions_breakdown`	Emissions split across materials, packaging, decoration, transport, and manufacturing
`last_calculated_at`	When the assessment was last run
`results_url`	Link to the full interactive results page — safe to share publicly
`pdf_url`	Link to the PDF report — stable, permanent URL safe to share or embed

Error responses

Status	Meaning
401	Invalid or missing API key
400	Missing required parameter (e.g. `sku`)
404	No assessed product found for that SKU
429	Rate limit exceeded — wait and retry
500	Server error

Rate limits summary

Endpoint	Limit
`/api/partner/emissions-totals`	2 requests / 24h
`/api/partner/emissions-by-sku`	1,000 requests per SKU / 24h