Quick Start
Get your first carbon rating response in under two minutes. All you need is an API key — request one via the button above and you'll receive sandbox credentials immediately.
Create an account at syne.com/request-access. Sandbox keys are issued instantly. Production keys are enabled after identity verification, typically within one business day.
All requests go to https://api.syne.com/v2. Authenticate by including your API key in the Authorization: Bearer <key> header on every request.
Authorization: Bearer sk_live_xxxxxxxxxxxxxxxxxxxxxxxx Content-Type: application/json Accept: application/json
Fetch a carbon rating using the project's registry ID. SYNE supports Verra VCS (prefix VCS-), Gold Standard (GS-), ACR (ACR-), CAR (CAR-), and Teravent (TVT-) project IDs natively.
curl https://api.syne.com/v2/ratings/VCS-1360 \ -H "Authorization: Bearer sk_sandbox_xxxx"
Use the sidebar to explore all available endpoints. The sandbox environment includes a full dataset of 200 projects across all registries and project types — safe to test against without rate limit concerns.
Authentication
SYNE Carbon uses Bearer token authentication. Every request must include a valid API key in the Authorization header. Keys are scoped by access level and tied to a single account.
Full API access against a static 200-project dataset. No rate limits. Issues instantly on registration. Use for development and integration testing.
Live access to the full 3,200+ project database and real-time market data. Rate limits apply per plan. Requires identity verification before activation.
Production keys limited to specific API namespaces (e.g., ratings-only, earth-only). Use for embedding partial API access in third-party products or microservices.
{
"error": "unauthorized",
"message": "Missing or invalid API key. Include Authorization: Bearer <key>",
"status": 401
}Carbon Ratings API
Access SYNE Carbon's independent quality ratings for 3,200+ carbon projects across all major registries. Each rating includes a composite score (0–100), individual factor scores across 10 dimensions, and a full rating history.
{
"project_id": "VCS-1360",
"registry": "Verra VCS",
"name": "REDD+ Madre de Dios, Peru",
"type": "REDD+",
"rating": "AAA",
"score": 94.2,
"factors": {
"additionality": 96,
"permanence": 91,
"mrvQuality": 95,
"baselineIntegrity":93,
"cobenefits": 93,
"leakage": 92,
"politicalRisk": 88,
"projectIntegrity": 97,
"sdgAlignment": 94,
"corsiaEligible": "yes"
},
"lastUpdated": "2026-03-04T09:15:00Z",
"nextReview": "2026-03-20T00:00:00Z"
}Returns the complete rating history for a project — every rating tier change, factor score update, and review event since SYNE first covered the project. Useful for monitoring rating trajectory and identifying quality trends.
Market Intelligence API
Real-time and historical pricing for 40+ compliance and voluntary carbon markets. Registry flow data, forward curves, and project pipeline intelligence.
{
"market": "EU_ETS",
"instrument": "EUA_DEC25",
"price": 63.40,
"currency": "EUR",
"change_pct": 0.9,
"volume_lots": 48200,
"timestamp": "2026-03-04T14:30:00Z"
}Returns registry flow events — credit issuances, retirements, transfers, and cancellations — across all integrated registries. Filter by registry, project type, vintage, or event type. Updated within 15 minutes of registry events being published.
Earth Intelligence API
Query satellite-derived vegetation, biomass, and land-use change data at project-polygon resolution. Submit a GeoJSON polygon and receive the complete Earth Intelligence data package for that area.
Submit a GeoJSON polygon boundary. Returns NDVI, EVI, canopy cover, land-use classification, and change detection metrics from the most recent available Sentinel-2 pass. Historical time series available via the from / to parameters.
{
"polygon": {
"type": "Polygon",
"coordinates": [[
[-71.2, -12.4],
[-70.8, -12.4],
[-70.8, -12.8],
[-71.2, -12.8],
[-71.2, -12.4]
]]
},
"from": "2020-01-01",
"to": "2026-03-01",
"metrics": ["ndvi", "canopy_cover"]
}Returns SAR-derived above-ground biomass (AGB) estimates in tCO₂e/ha for a rated project area — including current AGB, baseline AGB (at project start), and annual change. Fuses Sentinel-1 C-Band and ALOS-2 PALSAR L-Band data for high-biomass tropical projects.
Returns active deforestation and fire alerts across all monitored carbon projects. Filter by project ID, alert type, or date range. Alerts are generated within 24 hours of satellite confirmation. Each alert includes affected area (ha), estimated carbon stock impact (tCO₂e), and confidence level.
WebSocket Streams
Real-time data streams via WebSocket for live market prices, rating updates, and earth intelligence alerts. Connect to wss://stream.syne.com/v2 with your API key as a query parameter.
Tick-by-tick price updates for any monitored carbon market. Messages published on every trade event, typically every 15–30 seconds during active trading hours.
Real-time stream of rating tier changes and significant factor score updates. Filter by registry, project type, or rating tier. Subscribe to specific project IDs for targeted monitoring.
Real-time deforestation detection, fire alerts, and carbon stock change events. Messages include affected project ID, alert type, area affected, estimated tCO₂e impact, and confidence score.
const ws = new WebSocket( 'wss://stream.syne.com/v2/earth/alerts?apiKey=sk_live_xxxx' ); ws.onmessage = (event) => { const alert = JSON.parse(event.data); console.log(`Alert: ${alert.type} on ${alert.project_id}`); console.log(`Area: ${alert.area_ha} ha — ${alert.carbon_impact_tco2e} tCO₂e`); };
SDKs & Libraries
Official client libraries for the most common languages and environments. All SDKs are open source, MIT licensed, and maintained by the SYNE Carbon developer team.
Full API coverage including async/await support, automatic pagination, and pandas DataFrame export for market data and rating time series.
Typed TypeScript client with promise-based requests, WebSocket stream helpers, and Node.js and browser compatibility. Full type definitions included.
R client optimised for research workflows — tidy data outputs, ggplot2-compatible time series data, and vignettes for carbon ratings analysis and Earth Intelligence queries.
Complete OpenAPI 3.1 specification for generating client code in any language. Use with Swagger Codegen, OpenAPI Generator, or Postman import.
Rate Limits & Plans
Rate limits are applied per API key at the endpoint level. All limits use a sliding 60-second window. Responses include X-RateLimit-Remaining and X-RateLimit-Reset headers.
Error Codes
SYNE Carbon API uses standard HTTP status codes. All error responses include a JSON body with an error code string and a human-readable message.