API discovery: The public source is api.gouv.fr's Impact CO2 catalog entry plus the OpenAPI definition served from `impactco2.fr/api/v1`, including `/transport`, `/chauffage`, `/fruitsetlegumes`, `/thematiques`, and `/thematiques/ecv/{id}`.
This is compact, not the lead, because it is an integration source for product and governance teams, not fresh movement in today's agent-runtime source scan.
Creative example
Ask an agent to compare the CO2 estimate for a Paris-Lyon trip by TGV, car, and plane, then turn the answer into a caveated travel-policy note with the exact endpoint parameters it used.
Copy-paste agent instruction
Read https://github.com/betagouv/api.gouv.fr/blob/master/_data/api/api-impact-co2.md and https://github.com/betagouv/api.gouv.fr/blob/master/public/swaggers/api-impactco2.json. Build a minimal test plan for Impact CO2: call /transport with km=465 and displayAll=1, call /chauffage with m2=63, and call /thematiques/ecv/numerique?detail=1. Mark API-key use as recommended and do not present estimates as certified accounting.What to check first
The caveat is measurement context: the OpenAPI file says API keys are used for monitoring and may be required if access is restricted. What to watch is whether Impact CO2 adds clearer sample responses and versioned data provenance for agent-generated reports.