Calling Slack API methods

While building your Run On Slack functions, you can access and make calls to the Slack API.

To do this, you will:

1. Import the API library →
2. Add token to your function handler →
3. Instantiate a Slack API client object →
4. Make an API call →

1. Import the API library

The first step in making API calls in your Run On Slack functions is to import the API library:

import type { FunctionHandler } from "deno-slack-sdk/types.ts";
import { SlackAPI } from "deno-slack-api/mod.ts"; // Add this

2. Add token to your function handler

The next step is to add the token helper to your function handler:

import type { FunctionHandler } from "deno-slack-sdk/types.ts";
import { SlackAPI } from "deno-slack-api/mod.ts";

const reverse: FunctionHandler<any, any> = async (
  { inputs, env, token }, // Add `token` here
) => {
  
  // ...

3. Instantiate a Slack API client

Then, instantiate the Slack API client by passing along the token helper:

import type { FunctionHandler } from "deno-slack-sdk/types.ts";
import { SlackAPI } from "deno-slack-api/mod.ts";

const reverse: FunctionHandler<any, any> = async (
  { inputs, env, token }, 
) => {
  
  const client = SlackAPI(token, {}); // Add this
  
  // ...

The second argument to SlackAPI is an options object; this can be empty.

4. Make an API call

Finally, make the API call using client.apiCall(...):

import type { FunctionHandler } from "deno-slack-sdk/types.ts";
import { SlackAPI } from "deno-slack-api/mod.ts";

const reverse: FunctionHandler<any, any> = async (
  { inputs, env, token }, 
) => {
  
  const client = SlackAPI(token, {});

  // Call an API method in one of two ways.

  // Option #1: use client.apiCall(<method name>)
  await client.apiCall('chat.postMessage', {
    channel: inputs.some_channel,
    text: `You said "${inputs.some_string}"`
  });

  // Option #2: use client.methodGroup.method
  await client.chat.postMessage({
    channel: inputs.some_channel,
    text: `You said "${inputs.some_string}"`
  });

  
  // ...

Most API endpoints require specific permission scopes. Add scopes to your app by listing them in the botScopes property of your manifest.