We can regularly upload and share local files on our system using Slack API calls.

Let’s look at the following endpoints in this lesson:

Parameter	Type	Category	Description
`token`	token	required	Authentication tokens carry the required scopes that govern the usage of different Slack applications and APIs. We usually pass these tokens as an HTTP Authorization header or as a POST parameter.
`channels`	string	optional	This is a comma-separated list of channel names or IDs where the file will be shared.
`content`	string	optional	These are the contents of the file we send via a POST variable. If you are omitting this parameter, you must provide a `file`.
`file`	string	optional	These are files we send via `multipart/form-data` (for posting entire files as part of a form submission when using the POST request). If you are omitting this parameter, you must submit `content`.
`filename`	string	optional	This is the file name.
`filetype`	string	optional	A file type identifier, such as `auto` or `python`.
`initial_comment`	string	optional	This is the message text introducing the file in specified `channels`.
`thread_ts`	string	optional	This provides another message's `ts` value to upload this file as a reply. We can not use a reply's `ts` value. Instead, we use its parent instead.
`title`	string	optional	This is the title of the file.

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index.js

mytext.txt

import fetch from "node-fetch";
import { promises as fs } from "fs";
// Defining a function to read a local file
async function readLocalFile(filename) {
  try {
    const data = await fs.readFile(filename, { encoding: "utf8" });
    return data;
  } catch (err) {
    console.log(err);
  }
}
const url = new URL("https://slack.com/api/files.upload");
const headerParameters = {
  Authorization: "Bearer {{TOKEN}}",
  "Content-Type": "application/x-www-form-urlencoded",
};
async function uploadFile() {
  try {
    const filename = "mytext.txt";
    const fileContent = await readLocalFile(filename);
    const bodyParameters = new URLSearchParams({
      channels: "{{CHANNEL_ID}}",
      content: fileContent,
      filename: filename,
      filetype: "txt",
    });
    const options = {
      method: "POST",
      headers: headerParameters,
      body: bodyParameters,
    };
    const response = await fetch(url, options);
    printResponse(response);
  } catch (error) {
    printError(error);
  }
}
uploadFile();

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import fetch from "node-fetch";
const url = new URL("https://slack.com/api/files.list");
const headerParameters = {
  Authorization: "Bearer {{TOKEN}}",
  "Content-Type": "application/json; charset=UTF-8",
};
const queryParameters = new URLSearchParams({
  channel: "{{CHANNEL_ID}}",
});
const options = {
  method: "GET",
  headers: headerParameters,
};
async function getFiles() {
  try {
    url.search = queryParameters;
    const response = await fetch(url, options);
    printResponse(response);
  } catch (error) {
    printError(error);
  }
}
getFiles();

Parameter	Type	Category	Description
`token`	token	required	Authentication tokens carry the required scopes that govern the usage of different Slack applications and APIs. We usually pass these tokens as an HTTP Authorization header or as a POST parameter.
`file`	string	required	This specifies a file by providing its ID.
`count`	string	optional	This is the number of items to return per page.
`cursor`	string	optional	This parameter is a string of characters used to "point" to the next "page" of data. We paginate through collections of data by setting the `cursor` parameter to a `next_cursor` attribute returned by a previous request's `response_metadata`.
`limit`	integer	optional	This indicates the maximum number of items to return. Fewer than the requested number of items may be returned, even if the end of the list hasn't been reached.
`page`	integer	optional	This is the page number of results to return.

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import fetch from "node-fetch";
const url = new URL("https://slack.com/api/files.info");
const headerParameters = {
  Authorization: "Bearer {{TOKEN}}",
  "Content-Type": "application/json; charset=UTF-8",
};
const queryParameters = new URLSearchParams({
  file: "{{FILE_ID}}",
});
const options = {
  method: "GET",
  headers: headerParameters,
};
async function getFileInfo() {
  try {
    url.search = queryParameters;
    const response = await fetch(url, options);
    printResponse(response);
  } catch (error) {
    printError(error);
  }
}
getFileInfo();

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import fetch from "node-fetch";
const url = new URL("https://slack.com/api/files.delete");
const headerParameters = {
  Authorization: "Bearer {{TOKEN}}",
  "Content-Type": "application/json; charset=UTF-8",
};
const bodyParameters = JSON.stringify({
  channel: "{{CHANNEL_ID}}",
  file: "{{FILE_ID}}",
});
const options = {
  method: "POST",
  headers: headerParameters,
  body: bodyParameters,
};
async function deleteFile() {
  try {
    const response = await fetch(url, options);
    printResponse(response);
  } catch (error) {
    printError(error);
  }
}
deleteFile();

Introduction

Chat Using the Application

Conversations Using an App

File Management

Users

Manage Reactions

Slack's Bolt Framework

Conclusion

Appendix

Local Files

Upload a file

Get a list of all files

Get file information

Delete a file