ChatGPT Custom GPTs · OpenAI's custom assistants with tool calls and Actions

Image and voice generation, callable from a custom ChatGPT GPT.

Custom ChatGPT GPTs support Actions, which are HTTPS-callable tools the GPT can invoke during a conversation. Gathos exposes a clean OpenAPI schema so wiring it as an Action takes about ten minutes.

Install
# In your custom GPT > Configure > Actions > Import from URL
https://api.gathos.com/openapi.json

A sample session

You
Make me 5 vertical Reels from this podcast episode link, with my channel style.
ChatGPT Custom GPTs
Calling the gathos.podcast_clip_factory action...
ChatGPT Custom GPTs
✓ Got 5 vertical MP4s. Want me to send them as direct download links here?
You
Yes. And generate a Hindi voiceover trailer narrated in my saved voice.
ChatGPT Custom GPTs
Calling gathos.tts with voice=clone-1, language=hi...
ChatGPT Custom GPTs
✓ trailer-hi.mp3 ready.

Why pair Gathos with ChatGPT Custom GPTs

01
OpenAPI schema means Actions setup is a paste
Gathos publishes a standard OpenAPI schema at https://api.gathos.com/openapi.json. ChatGPT Actions imports directly from a URL, so wiring takes about ten minutes per GPT, not a custom integration project.
02
API key per GPT means you can build product-specific assistants
Each Custom GPT can have its own Gathos API key. Build a YouTube-thumbnail GPT, a Shopify-product-shot GPT, a podcast-clipping GPT. Each one has scoped access and its own usage view.
03
ChatGPT loops are eager · flat pricing handles it
GPTs love iterating. A custom assistant that helps generate thumbnails will easily call the API 30 times per conversation. Per-image meters punish that. Gathos flat $18 makes iteration free.
04
Bundled image + voice means richer GPT outputs
A "build me a launch announcement" GPT can generate the poster, the social variants, the voiceover, and the multilingual dubs from one tool. Building that with two separate APIs is twice the wiring.

Frequently asked questions

How do I add Gathos as a ChatGPT Action?+
In your Custom GPT > Configure > Actions > Import from URL > paste https://api.gathos.com/openapi.json. Then add your Gathos API key in the auth section. Done.
Does this work with the free ChatGPT tier?+
Custom GPTs require ChatGPT Plus or higher. Once on Plus, your custom GPTs can call any Action.
Can I share my Gathos GPT with other people?+
Yes. Share the GPT link. Each user provides their own Gathos API key on first use, so you do not pay for their usage.
What about the GPT Store?+
Yes, you can publish a Gathos-powered GPT to the store. Many teams build niche GPTs (thumbnail generator, product shot factory) on top of Gathos and publish them.
How does this differ from MCP?+
ChatGPT Actions and MCP are different protocols solving similar problems. Gathos works through both. If you're inside ChatGPT, use Actions. If you're using Claude Code or Cursor, use MCP.

Using a different agent?

GitHub Copilot

Image and voice generation, plugged into GitHub Copilot.

GitHub Copilot supports custom agents and MCP servers in 2026, which means Gathos can be wired in as a callable tool inside any IDE that ships Copilot. The setup is one curl line and one config entry.

Continue

Image and voice generation in Continue.dev sessions.

Continue is the open-source alternative to Cursor, focused on developer control and self-hosting. It supports custom slash commands and tools through a clean config. Gathos plugs in as a callable tool so the agent can generate assets from the same editor session.

Aider

Image and voice generation, called from inside Aider sessions.

Aider is a terminal-first pair programmer that has stayed lean and fast. It does not ship with image generation or TTS, and the popular pattern is to bolt those on as external commands. Gathos slots in as a Bash-callable tool so an Aider session can generate assets without leaving the terminal.

Claude Code

Image generation and voice cloning for Claude Code.

Claude Code is the fastest-growing agent for power users. Gathos is the unified image + TTS API that plugs into Claude Code with a single install command. This page shows the install, a sample session, and the pre-built skills most teams install first.

Gemini CLI

Image and voice generation, native to Gemini CLI.

Gemini CLI's Skills spec went GA in early 2026 · same single-file markdown convention Anthropic and Codeium adopted. Gathos installs as a Gemini CLI skill so the agent can generate images and voiceover from any terminal session.

Cursor

Image generation and voice cloning in Cursor.

Cursor is where millions of developers write code every day. Gathos plugs into Cursor as a set of agent-callable skills · you describe what you want in a chat message, Cursor runs the API, and the output lands in your project folder. Flat $18/month.

Windsurf

Image generation and voice cloning, native to Windsurf.

Windsurf shipped Cascade Skills in Wave 13 (January 2026), and the spec is the same single-file markdown convention Anthropic and Cursor adopted. Gathos plugs in as a Cascade Skill so the agent can generate thumbnails, product shots, voiceover, and dubbed videos without you leaving the editor.

Plug Gathos into ChatGPT Custom GPTs in one command.