{"service":"dVeracity Semantic API","version":"1","description":"Natural-language and template queries over the dVeracity verified-emissions knowledge graph (Open Footprint / PPDM / OGMP-methane virtual knowledge graphs).","authentication":{"type":"api_key","header":"X-Api-Key","obtain":"Create a key at POST /api/v1/api-keys (requires an api-tier subscription; see pricing_url). Keys are prefixed dvrc_.","pricing_url":"https://dveracity.com/pricing","keri":{"description":"Optional verified-agent identity layer (vLEI). An agent holding a dVeracity Agent Authorization credential (issued by its Legal Entity, chained to the GLEIF root) authenticates by verifiable presentation instead of secret alone; usage is then attributed to the agent AID and Legal Entity LEI. Billing still requires the API key.","challenge":{"path":"/api/v1/semantic/auth/challenge","method":"GET"},"exchange":{"path":"/api/v1/semantic/auth/keri","method":"POST","body":{"aid":"agent AID (issuee of the credential)","nonce":"from /auth/challenge","presentation":"self-contained CESR credential presentation","sig":"optional signature over the nonce by the agent AID"}},"session_header":"X-Keri-Session","credential_schema":"EFyhIYqAgOxRNikVRQzcvJpHr_589-_40oMo4Urc2--J"}},"billing":{"unit":"credits","purchase":{"path":"/api/v1/vaas/credits/purchase","method":"POST"},"balance":{"path":"/api/v1/vaas/credits","method":"GET"},"payment_required_semantics":"A response of HTTP 402 with body {error: \"insufficient_credits\", balance, needed, purchaseUrl} means the account has run out of credits. Purchase credits (or ask your human operator to subscribe at pricing_url), then retry the request."},"endpoints":[{"path":"/api/v1/semantic/query","method":"POST","credits":1,"body":{"query":"natural-language question (string, required)","sessionId":"optional"},"description":"Answers a natural-language question by translating it to SPARQL and executing it against the verified-emissions knowledge graph."},{"path":"/api/v1/semantic/templates","method":"GET","credits":0,"description":"Catalog of supported query templates and their parameters."}]}