Claude Slack GIF Creator

This repo shows how to build a bot powered by Claude that creates custom Slackmoji-ready GIFs.

Or, in GIF form:

A bot powered by Claude that creates custom Slackmoji-ready GIFs

The bot runs on Modal and uses the Claude Agent SDK with the slack-gif-creator skill from Anthropic.

Features

Natural Language GIF Generation: Describe what you want and Claude will create a 128x128 emoji-optimized GIF
Persistent Threads: Each Slack thread creates a conversation context, persisted on Modal
Image Upload Support: Upload images to the bot to incorporate them into your GIFs
Background Removal: Backgrounds removed using the rembg tool, so you can make GIFs of your friends
Real-time Tool Logging: See Claude’s tool usage in the Slack thread as it works

Architecture

The bot consists of three main components: a Slack Bot Server, a Claude Agent Sandbox, and an Anthropic API Proxy.

Slack Bot Server

This component handles Slack events (mentions and thread replies) and manages Modal Sandboxes. It’s a simple FastAPI ASGI app hosted on Modal.

Claude Agent Sandbox

This component runs a Claude client and executes Claude skills, like Bash execution and GIF creation.

Because these skills are tantamount to giving the agent total control over the computing environment and we are going to allow anyone who can access the bot to prompt the agent, we need to isolate and secure this component. To that tend, it runs inside a Modal Sandbox. Modal can readily scale to hundreds or thousands of Sandboxes.

Each Slack thread gets its own persistent Modal Sandbox with a dedicated Volume for storing generated GIFs and session data.

Anthropic API Proxy

This component proxies requests to the Anthropic API.

The proxy keeps the API key out of the Sandbox. It’s included so that Claude can’t leak your API key when a naughty prompt hacker asks for a GIF containing it, as in the (mock) example below.

Fake API keys revealed in a GIF

Prerequisites

Python 3.10 or higher
A Modal account
A Slack workspace
An Anthropic API key

Setup

1. Install Dependencies

pip install modal

That’s it!

If you’ve never used Modal before on this machine, also run

modal setup

2. Configure Slack App

Create a new Slack app in your workspace.

Your Slack app needs:

OAuth Scopes

app_mentions:read
chat:write
files:read
files:write
channels:history
groups:history
im:history
mpim:history

Event Subscriptions:

app_mention
message.channels
message.groups
message.im
message.mpim

Create two Modal Secrets:

anthropic-secret with:

ANTHROPIC_API_KEY: Your Anthropic API key

claude-code-slackbot-secret with:

SLACK_BOT_TOKEN: Your Slack bot token (starts with xoxb-)
SLACK_SIGNING_SECRET: Your Slack app’s signing secret

modal deploy src/main.py

After deployment, Modal will provide a webhook URL. Add this URL to your Slack app’s Event Subscriptions Request URL.

Finally, install the app to your workspace and invite the bot to the channels where you want to use it.

Usage

Mention the Bot

Mention the bot in any channel with a description of the GIF you want:

@GIFBot create a GIF of a pelican riding a bicycle

Pelican riding a bicycle

Upload Images

Attach images to your message for the bot to incorporate:

@GIFBot make a party GIF of this entity that flashes the letters “AGI”

[attach image]

Are you feeling the AGI?

Background Removal

Request background removal for transparent GIFs:

@GIFBot make a GIF of this guy riding on a boat

[attach image with background]

Gongy ships

Thread Replies

Reply to the bot’s messages in a thread to continue the conversation:

@GIFBot make a GIF showing “A bot powered by Claude that creates custom Slackmoji-ready GIFs.” on a screen

the text runs off the screen, fix the wrapping