Short answer: Vocode is an open-source library for developers who want to build their own voice agents, including ones that make phone calls. You write the code, pick the speech and voice providers and host it. OsmO is a finished service you connect to ChatGPT, Claude or another AI app. If you want full control and have the skills, Vocode is free to build on. If you just want a call made, OsmO is ready now.
Vocode's main library, vocode-core, is open source under the MIT licence and written in Python.
Its GitHub page showed the last update to vocode-core on 15 November 2024 when we checked.
Building with Vocode means running your own code, phone line and providers.
OsmO needs no code: 50 free credits, then 3 per answered call.
How it works
- Sign in with your mobile numberYou get 50 free credits. Nothing to pay.
- Add OsmO to ClaudeChatGPT, Claude, Grok and other apps that take connectors.
- Ask it to callOsmO calls, talks, and tells you what was said.
The full guide
What Vocode gives you
Vocode's documentation describes building blocks for voice agents: conversation handling, turn-taking, links to speech-to-text and text-to-speech providers, and support for phone calls, the web and Zoom. Its examples include systems that answer or make phone calls. The docs also describe a hosted API for automating inbound and outbound calls, which you sign up for separately.
The trade-off with any open-source library is that you become the operator: you deploy it, connect a phone provider, pay that provider and the model vendors, and keep it running.
| Vocode (open source) | OsmO For my AI | |
|---|---|---|
| What it is | A Python library for building voice agents | A ready-made calling service |
| Licence and cost | MIT licence; you pay your own providers | 50 free credits, then 3 per answered call |
| Skills needed | Software development and hosting | None: add a connector and sign in |
| Phone line | Bring your own telephony | Included |
| Recent activity | vocode-core last updated 15 Nov 2024 on GitHub | A hosted service; nothing to maintain |
When Vocode is the better choice
- You want to study or change how a voice agent works, line by line.
- You need to run everything on your own servers.
- You are building a product, and the call logic is the product.
- You are comfortable maintaining code that has not had recent upstream updates.
When OsmO is the better choice
When the call is the goal, not the code. OsmO already handles dialling, phone menus, hold queues and the conversation itself. Your AI app decides what to ask, OsmO makes the call, and the answer comes back to the chat. Developers can also add it to Claude Code, Codex or Cursor with one command, so a coding session can make a call when a task needs a real-world answer.
What it costs
OsmO For my AI starts with 50 free credits when you sign in with your mobile number, with no card. An answered call uses 3 credits however long it lasts, and a call nobody answers is free, so the free credits cover about 16 answered calls. When they run out you can keep calling from the OsmO app.
You can sign in with a mobile number from the United States, Canada, the United Kingdom or Australia (India too), and calls are placed from the OsmO number for your country. OsmO calls listed businesses in your own country, such as shops, clinics, restaurants and offices, and toll-free helplines. With the free web credits it does not call personal numbers; with the OsmO app it can also call your saved contacts.
The bottom line
Open source is a good fit when you want to own every piece and have time to maintain it. Check how active a project is before you build a business on it; that is true of any library, not only Vocode. If your real need is a few calls a week from an AI app, a hosted service saves you the hosting, the phone account and the upkeep, and you can still use it from a developer workflow through MCP. Many teams prototype with a library and then decide the call itself was all they needed.
Questions people ask
Is Vocode still maintained?
We cannot say for certain. When we checked on 13 November 2026, the vocode-core repository on GitHub showed its last update on 15 November 2024. Check the repository for the current state.
Can I self-host OsmO?
No. OsmO is a hosted service. If self-hosting matters, an open-source library such as Vocode is the route.
Sources
Checked November 13, 2026. Vendors change their products often; follow the links for the current version.
Keep reading
- OsmO vs Vapi: build a voice agent, or just have your AI call?A developer platform for building voice agents vs calling from your AI app.Read ›
- Can OpenAI Codex make phone calls?Add OsmO with codex mcp add and sign in once.Read ›
- Can Cursor make phone calls?Add OsmO to mcp.json and Cursor's agent can call.Read ›