# Tryton API: Getting nested objects using fields
**URL:** https://discuss.tryton.org/t/tryton-api-getting-nested-objects-using-fields/6171
**Category:** Developer
**Tags:** party
**Created:** [May 23, 2023, 2:39pm UTC](https://discuss.tryton.org/t/tryton-api-getting-nested-objects-using-fields/6171 "2023-05-23T14:39:19Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@meadev](https://discuss.tryton.org/u/meadev)
#### Post date: [May 23, 2023, 2:39pm UTC](https://discuss.tryton.org/t/tryton-api-getting-nested-objects-using-fields/6171/1 "2023-05-23T14:39:19Z")
Hello,
We are consuming our client’s API (base on Tryton), but there custom modules are not documented. I would like if know if there any possible optimisation in the folowing calls:
the need: given a **party\_id** , we need to fin all the **covered\_elements** data related to the party contracts.
Current solution:
Call 1: {{WEB\_URL}}/party/ **89** /?\_fields=contracts
Result:
```auto
{
"_": "party.party",
"id": 89,
"siren": null,
"ssn": "123",
"death_date": null,
"forced_claim_bank_account": {
"_": "bank.account",
"id": null
},
"gender": "female",
"commercial_name": null,
"contracts": [
{
"_": "contract",
"id": 121253,
"signature_date": "2020-10-02",
"subscriber": {
"_": "party.party",
"id": 89
},
"rec_name": "CT8901"
}
]
}
```
Call 2: {{WEB\_URL}}/contract/121253/?\_fields= covered\_elements
Result:
```auto
{
"_": "contract",
"id": 121253,
"signature_date": "2020-10-02",
"contract_number": "CT8901",
"covered_elements": [
{
"_": "contract.covered_element",
"id": 79221,
"write_date": "2022-08-23 19:17:42.174",
"party": {
"_": "party.party",
"id": 89
},
{
"_": "contract.covered_element",
"id": 79222,
"write_date": "2022-08-23 19:19:27.114",
"party": {
"_": "party.party",
"id": 90
},
}
],
}
```
The question: is there any way to reach Contract.covered\_elements directly from the 1st call ?
something like:
{{WEB\_URL}}/party/ **89** /?\_fields=contracts,contracts.covered\_elements
{{WEB\_URL}}/party/ **89** /?\_fields=contracts,contracts:covered\_elements
…
Needed result:
```auto
{
"_": "party.party",
"id": 89,
"siren": null,
"ssn": "123",
"death_date": null,
"forced_claim_bank_account": {
"_": "bank.account",
"id": null
},
"gender": "female",
"commercial_name": null,
"contracts": [
{
"_": "contract",
"id": 121253,
"signature_date": "2020-10-02",
"subscriber": {
"_": "party.party",
"id": 89
},
"rec_name": "CT8901",
"covered_elements": [
{
"_": "contract.covered_element",
"id": 79221,
"write_date": "2022-08-23 19:17:42.174",
"party": {
"_": "party.party",
"id": 89
},
{
"_": "contract.covered_element",
"id": 79222,
"write_date": "2022-08-23 19:19:27.114",
"party": {
"_": "party.party",
"id": 90
},
}
],
}
]
}
```
Thanks.
---
### Author:  [@ced](https://discuss.tryton.org/u/ced)
#### Post date: [May 23, 2023, 3:56pm UTC](https://discuss.tryton.org/t/tryton-api-getting-nested-objects-using-fields/6171/2 "2023-05-23T15:56:28Z")
Which API are you talking because it does not look like the [RPC](https://docs.tryton.org/projects/server/en/latest/ref/rpc.html) api of Tryton?
---
### Author:  [@meadev](https://discuss.tryton.org/u/meadev)
#### Post date: [May 24, 2023, 9:45am UTC](https://discuss.tryton.org/t/tryton-api-getting-nested-objects-using-fields/6171/3 "2023-05-24T09:45:51Z")
Our client claim it’s a custom solution based on Tryton, i searched on the tryton documentation about API but fount nothing similar to what we are consuming.
---
### Author:  [@ced](https://discuss.tryton.org/u/ced)
#### Post date: [May 24, 2023, 11:54am UTC](https://discuss.tryton.org/t/tryton-api-getting-nested-objects-using-fields/6171/4 "2023-05-24T11:54:44Z")
So it is probably a custom API developed by the client. You should ask for their documentation.