# Write implementation

{% hint style="success" %}
This is the official documentation of the `@forestadmin/agent` Node.js agent.
{% endhint %}

Making your records editable is achieved by implementing the `create`, `update` and `delete` methods.

The 3 methods take a [filter](/developer-guide-agents-nodejs/data-sources/getting-started/queries/filters.md) as a parameter but note that, unlike the `list` method, there is no need to support paging.

```javascript
const { BaseCollection } = require('@forestadmin/datasource-toolkit');
const axios = require('axios'); // client for the target API

/** Naive implementation of create, update and delete on a REST API */
class MyCollection extends BaseCollection {
  constructor() {
    this.addField('id', { /* ... */ isReadOnly: true });
    this.addField('title', { /* ... */ isReadOnly: false });
  }

  async create(caller, records) {
    const promises = records.map(async record => {
      const response = await axios.post('https://my-api/my-collection', record);
      return response.data;
    });

    return Promise.all(promises); // Must return newly created records
  }

  async update(caller, filter, patch) {
    const recordIds = await this.list(caller, filter, ['id']); // Retrieve ids
    const promises = recordIds.map(async ({ id }) => {
      await axios.patch(`https://my-api/my-collection/${id}`, patch);
    });

    await Promise.all(promises);
  }

  async delete(caller, filter) {
    const recordIds = await this.list(caller, filter, ['id']); // Retrieve ids
    const promises = recordIds.map(async ({ id }) => {
      await axios.delete(`https://my-api/my-collection/${id}`);
    });

    await Promise.all(promises);
  }
}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.forestadmin.com/developer-guide-agents-nodejs/data-sources/custom/translation/read-write.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.