# API Catalog explanation
**URL:** https://community.dremio.com/t/api-catalog-explanation/2022
**Category:** Uncategorized
**Created:** [October 16, 2018, 1:00pm UTC](https://community.dremio.com/t/api-catalog-explanation/2022 "2018-10-16T13:00:58Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Luca](https://community.dremio.com/u/Luca)
#### Post date: [October 16, 2018, 1:00pm UTC](https://community.dremio.com/t/api-catalog-explanation/2022/1 "2018-10-16T13:00:58Z")
Hi,
I was playing with Dremio API and I can’t understand how to work with catalogs.
After I get the login token, I do:
**GET [http://localhost:9047/api/v3/catalog](http://localhost:9047/api/v3/catalog)**
and the result is something like this:
{
“data”: [
{
“id”: “0fef5580-2192-4d8c-b1c0-d41b00ea134d”,
“path”: [
“@ds-ui”
],
“tag”: “0”,
“type”: “CONTAINER”,
“containerType”: “HOME”
},
{
“id”: “f0eda547-f146-481b-babe-ad156d870a11”,
“path”: [
“Test”
],
“tag”: “0”,
“type”: “CONTAINER”,
“containerType”: “SOURCE”
}
]
}
**GET [http://localhost:9047/api/v3/catalog/f0eda547-f146-481b-babe-ad156d870a11](http://localhost:9047/api/v3/catalog/f0eda547-f146-481b-babe-ad156d870a11)**
{
“entityType”: “source”,
“config”: {
“path”: “/var/data/warehouse”
},
“state”: {
“status”: “good”,
“messages”: []
},
“id”: “f0eda547-f146-481b-babe-ad156d870a11”,
“tag”: “0”,
“type”: “NAS”,
“name”: “Test”,
“createdAt”: “2018-10-16T07:36:14.892Z”,
“metadataPolicy”: {
“authTTLMs”: 86400000,
“namesRefreshMs”: 3600000,
“datasetRefreshAfterMs”: 60000,
“datasetExpireAfterMs”: 180000,
“datasetUpdateMode”: “PREFETCH\_QUERIED”
},
“accelerationGracePeriodMs”: 10800000,
“accelerationRefreshPeriodMs”: 3600000,
“accelerationNeverExpire”: false,
“accelerationNeverRefresh”: false,
“children”: [
{
“id”: “dremio:/Test/“prova””,
“path”: [
“Test”,
““prova””
],
“type”: “CONTAINER”,
“containerType”: “FOLDER”
}
]
}
Now comes the problem, i want to go down and reach the entity **/Test/prova/000** that is an already defined dataset over a folder that contains a parquet file. But first i want to check **/Test/“prova”**.
Accordingly to the [API reference](https://docs.dremio.com/rest-api/catalog/endpoints.html) I try getting a folder using it’s ID:
**GET [http://localhost:9047/api/v3/catalog/dremio%3A/Test/“prova”](http://localhost:9047/api/v3/catalog/dremio%3A/Test/%22prova%22)** (there are percent22 before and after “prova” but this forum replaces them with double quotes)
This fails… and this is exactly the same url that [the tutorial](https://www.dremio.com/tutorials/using-the-rest-api/) tries to get. The error is “404 Not found”.
To test if there is some url encoding problem, I tried with an external tool to play with escapes but none of my attempts worked, I always get 404.
Where’s the problem?
Thanks
---
### Author:  [@doron](https://community.dremio.com/u/doron)
#### Post date: [October 16, 2018, 3:40pm UTC](https://community.dremio.com/t/api-catalog-explanation/2022/2 "2018-10-16T15:40:45Z")
Hi,
You need to URL encode the entire id - so it would be `dremio%3A%2FTest%2F%E2%80%9Cprova%E2%80%9D`. If you are on Dremio 2.1.x, you can also use our [by path](http://docs.dremio.com/rest-api/catalog/endpoints.html#retrieve-a-catalog-entity-by-path) endpoint to avoid walking the tree.
---
### Author:  [@Luca](https://community.dremio.com/u/Luca)
#### Post date: [October 17, 2018, 6:50am UTC](https://community.dremio.com/t/api-catalog-explanation/2022/3 "2018-10-17T06:50:52Z")
You’re right, I was using “quote” function from python urllib, and that function does not encode slashes by default (you have to pass **safe=’’** to escape also slahes). Doing that, the code works fine. “by path” approach however seems easier, so I’ll go with it.
Thank you
---
### Author:  [@Richard-biz](https://community.dremio.com/u/Richard-biz)
#### Post date: [December 31, 2018, 11:43pm UTC](https://community.dremio.com/t/api-catalog-explanation/2022/4 "2018-12-31T23:43:29Z")
@doron I am working on taking preview on my dataset through API i know in dremio documentaion there is no such kind of API for that, so I am taking the Internal API for that,
“/apiv2/datasets/new\_untitled\_sql?newVersion=0009519538063077” , When i am using this API am facing most of time either 404 or 400 bad request, I know this is coming because of the Version ID need to Be unique format, May i know how to Solve the Bad request Issue in the Preview Response from Dremio. Could you tell me how to Archive this case.
---
### Author:  [@doron](https://community.dremio.com/u/doron)
#### Post date: [January 1, 2019, 12:31am UTC](https://community.dremio.com/t/api-catalog-explanation/2022/5 "2019-01-01T00:31:08Z")
Hi,
The v2 APIs are considered internal and may change at any time. Currently we do not have a stable API that allows previews. You could always add a LIMIT clause to your sql to approximate it.
---
### Author:  [@Richard-biz](https://community.dremio.com/u/Richard-biz)
#### Post date: [January 1, 2019, 2:11am UTC](https://community.dremio.com/t/api-catalog-explanation/2022/6 "2019-01-01T02:11:12Z")
Ok,Thanks for the Information @doron, We already using limit 10 , But even though we are facing this issue.
---
### Author:  [@doron](https://community.dremio.com/u/doron)
#### Post date: [January 2, 2019, 4:25pm UTC](https://community.dremio.com/t/api-catalog-explanation/2022/7 "2019-01-02T16:25:35Z")
You can use the [SQL API](http://docs.dremio.com/rest-api/sql/) with `LIMIT` to approximate previews. Are oyu saying you still see very slow queries?
---
### Author:  [@Richard-biz](https://community.dremio.com/u/Richard-biz)
#### Post date: [January 2, 2019, 4:48pm UTC](https://community.dremio.com/t/api-catalog-explanation/2022/8 "2019-01-02T16:48:12Z")
Thanks @doron for your Support, Yes Right now we are doing instead of Internal API we are using in Rest sql API.