| mrv | No | Return the N most recent available values per country (1–100), clamped upstream to the length of the series. Rows are mrv × countries, so page through them with per_page. Mutually exclusive with date_range. | |
| page | No | Pagination page number (1-based). | |
| per_page | No | Results per page (default: server default, max: 1000). Use higher values for "all" country queries. | |
| countries | Yes | Country codes. Accepts: ISO2 (US, CN), ISO3 (USA, CHN), regional aggregate codes (EAS, LCN, MEA, SAS, SSF, ECS, NAC), income group codes (HIC, UMC, LMC, LIC), world code (WLD), or "all" for every entry (use pagination). Pass a single string or an array of codes for multi-country queries. At least one code is required — an empty value is rejected rather than treated as "all". | |
| date_range | No | Time window to filter observations to. Accepts a whole year (`2020`), a quarter (`2020Q1`), or a month (`2020M03`), or a range of two periods of the same type separated by a colon, earliest first (`2010:2023`, `2020Q1:2021Q4`, `2020M01:2020M06`). A window and an observation match whenever the periods overlap, so a year window also selects the quarters and months inside it. A window covering no part of the series returns zero observations rather than the full series. Mutually exclusive with mrv. | |
| indicator_id | Yes | Indicator code to query (e.g. NY.GDP.PCAP.CD, SP.POP.TOTL). Use worldbank_search_indicators to find valid IDs. | |