JAMES
Joint Automatic Measurement and Evaluation System
JAMES is a web service by TNO for monitoring and evaluating child growth and development according to Dutch youth healthcare standards.
Growth charts
Access high-quality growth charts used by Dutch youth healthcare (JGZ). Draw charts for height, weight, head circumference, and D-score. Charts are available for term and preterm children.
Developmental assessment
Upload child measurements as JSON. Screen for abnormal growth or development, and apply JGZ referral guidelines.
Prediction
Predict future growth and development using curve matching. Supports height, weight, and developmental trajectories based on longitudinal reference data.
API
JAMES exposes a REST API. All endpoints accept JSON and return JSON, SVG, or PNG.
| Endpoint | Description |
|---|---|
POST /data/upload |
Upload and parse child data (BDS format) |
POST /charts/draw |
Draw a growth chart |
POST /screeners/apply |
Apply JGZ screening guidelines |
POST /dscore/calculate |
Calculate D-score |
POST /dcat/calculate |
Adaptive developmental testing (DCAT) |
POST /ddomain/calculate |
Calculate domain-specific D-scores |
POST /vwc/select |
Select optimal Van Wiechen milestones |
POST /site/request |
Generate a personalised child site URL |
POST /version |
Return JAMES and package version numbers |
Full API reference with interactive examples: james.groeidiagrammen.nl/docs/
Resources
| Getting started | Step-by-step introduction |
| Frontend element | Chart gallery |
| API documentation | Interactive Swagger UI with all endpoints |
| R package documentation | Full reference for the james R package |
| GitHub | Source code and issue tracker |
| JSON schema | BDS v3.1 data format |
| Basisdataset JGZ | Official BDS specification |
Availability
The JAMES API is openly available at https://james.groeidiagrammen.nl for exploration and testing. Rate limits apply. For production use, contact Olivier Blanson Henkemans.
Further reading
Van Buuren S (2025). JAMES Workshop Arnhem 2025. http://growthcharts.org/arnhem2025/
Van Buuren S, Huizing AHJ, Eekhout I (2026). JAMES: Joint Automatic Measurement and Evaluation System. TNO, Dept Child Health, The Netherlands. https://james.groeidiagrammen.nl
Blanson Henkemans O, van Buuren S, Vugs S, Boerema S & Putrik P (2026). Mensgericht ontwerp van JAMES: Een gebruikersinterface voor het werken met voorspelmodellen in de JGZ. JGZ Tijdschrift Voor Jeugdgezondheidszorg. https://doi.org/10.61431/ra1tsh49
Sondeijker F, Segers E, Bijma H, Putrik P & Boerema S (2026). Praktijksimulatie van voorspelmodellen op basis van machine learning in geboortezorg en jeugdgezondheidszorg: Eerste ervaringen van zorgverleners en ouders. JGZ Tijdschrift Voor Jeugdgezondheidszorg. https://doi.org/10.61431/apv7q012
License
JAMES is licensed under the GNU Affero General Public License v3.