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Ideal for bibliometrics, research-impact, science-mapping and reference-management tools.","source":"OpenCitations — the open citation index, COCI (opencitations.net)","endpoints":["/v1/citations","/v1/references","/v1/count","/v1/meta"]},"meta":{"timestamp":"2026-06-01T16:23:10.603Z","request_id":"19d1c43c-79b7-442a-9844-90227fe193ca"},"status":"ok","message":"Meta retrieved","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}}},"x-oanor-pricing":[{"slug":"free","name":"Free","price_cents_month":0,"monthly_call_quota":2800,"rps_limit":2,"hard_limit":true},{"slug":"starter","name":"Starter","price_cents_month":760,"monthly_call_quota":58000,"rps_limit":8,"hard_limit":true},{"slug":"pro","name":"Pro","price_cents_month":2400,"monthly_call_quota":270000,"rps_limit":20,"hard_limit":true},{"slug":"mega","name":"Mega","price_cents_month":6300,"monthly_call_quota":950000,"rps_limit":50,"hard_limit":true}],"x-oanor-marketplace-url":"https://www.oanor.com/api/opencitations-api"}