> For the complete documentation index, see [llms.txt](https://guide.data.gov.sg/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guide.data.gov.sg/developer-guide/api-overview.md).
# API overview
There are two types of APIs on data.gov.sg.
1. **Real-Time APIs:**
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Please find a list of our real-time APIs [here](https://beta.data.gov.sg/datasets?formats=API)
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These are specific use-case APIs that allow you to query data such as weather and traffic conditions
2. **Collection and Dataset APIs:**
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API documentation can be found below
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These APIs allow you to query both collections and datasets, as well as to retrieve metadata and listings.
The API used to query a specific dataset for data can be found on the page `API v1`, under `Dataset Search`.
***
## Nomenclature
**Collection:**
A grouping of datasets, generally thematically
`collection_id` can be found in the URL of the dataset in this manner `https://data.gov.sg/collections/{collection_id}/view`
> For example - has the `collection_id` of `1`
**Dataset:**
A single unit of data, which can be tabular (e.g. csv, xlsx) or otherwise (e.g. geojson, kml)\
`dataset_id` can be found in the URL of the dataset in this manner `https://data.gov.sg/datasets/{dataset_id}/view`
> For example - has the `dataset_id` of `1`
## API Key
All Data.gov.sg APIs are public and can be accessed without an API key for testing purposes.
However, if you are using the APIs and datasets for **production workflows**, we strongly recommend you to use an **API key.**
This will grant you **higher rate limits**, **prioritised support** and **maintenance updates**