Live AI co-hosts for streamers and podcasters
Every stream needs a counterparty.
Counterparty builds AI co-hosts with a face, a voice and a point of view, who talk with you live on camera, run by Claude. The first is Cass. On our own show she argues the other side, puts her sources on screen, and moves her number when the evidence moves her.
sofyane, give me this week's position in one sentence I could bet against.
How a co-host is made
Every co-host is four parts, built once and reused in every stream.
Face
A 3D character from our Blender pipeline, which turns a rigged character into a talking face with 52 face shapes and 15 mouth shapes. A drawn 2D face works too, and a photoreal streamed face is in testing.
Voice
A streaming voice. The co-host's mouth follows the audio itself, so any voice lip-syncs.
Mind
Claude, with the co-host's personality, beliefs and house rules in its instructions. It hears the host, decides when to speak, and can be interrupted.
Tools
On-screen moves the co-host makes while it talks: a source card, a confidence meter, a poll, a predictions ledger.
Every co-host is an original character and says it's an AI. We don't make likenesses of real people.
Co-host no. 1
Cass, on Counterparty
Each week sofyane takes a position and Cass argues the other side. Every episode runs the same six segments, so a claim made one week gets checked in another.
- 01
Settlement
Last week's calls are settled on air, with the source that settles them on screen.
- 02
Position
sofyane states the week's thesis as one sentence you could bet against.
- 03
Cross
Cass cross-examines. Every claim needs a number, a name or a date.
- 04
Switch
On cue, Cass argues sofyane's side as hard as she argued her own.
- 05
The Room
The best listener arguments, read out by name, and a live poll.
- 06
The Call
Both hosts log a prediction with a number and a date, to be settled later.
Studio test · Episode zero
The studio is built
Counterparty records in its own browser studio: the host's camera on one side, Cass on the other, her sources and confidence meter part of the picture. Her mouth follows her own audio, and the studio saves the finished episode with a transcript, captions and separate audio tracks.
Cass's lines in this test are scripted. On the show they come from Claude, live.
- Claude drives Cass's tools as she speaks, and when the host cuts her off, Claude is told exactly which words the audience heard.
- Cass's 3D face is built from open-licensed parts in Blender, with 52 face shapes and 15 mouth shapes.
- Every episode saves the program video, separate audio tracks, a transcript, captions and a per-turn latency log.
- 23 automated tests cover the server, the Claude tool loop and interruptions.
The calls ledger
Predictions only count with a number and a date. These two were logged in episode zero.
| Call | Who | Settles | Confidence | Status |
|---|---|---|---|---|
| Fewer than one in five of the top 100 podcasts will have a regular AI co-host. | Cass | 31 Dec 2030 | 70% | Open |
| At least 40 of the top 100 podcasts will have a regular AI co-host. | sofyane | 31 Dec 2030 | 60% | Open |
Both calls get settled on air when their date comes.
Built on Claude
Every co-host runs on three Claude models, each picked for how fast it answers and what the job needs. Here they are in Cass.
Her voice on air
Writes every line Cass says, streamed sentence by sentence into her voice and lip sync, and calls her tools mid-answer: a source on screen, a new number on the meter, a call in the ledger, a poll. Every 15 seconds at most, it also gets a look at the host's camera.
The producer
Never on air. It sends Cass notes at each segment change and about every 45 seconds, and writes the show notes when the episode ends.
The listener
Reads each of the host's lines as they land and sets Cass's face while she listens: doubting, amused or conceding.
Why Sonnet speaks and Opus produces
Seconds from a question to the first word of the answer. Twelve seconds of silence is fine for a producer and fatal for a co-host.
Third-party measurements from Artificial Analysis (Anthropic API, 10k-token input), September 2026. Models on the live path in blue.
House rules. Cass is an AI and says so. She only cites sources her tools returned, and when she's wrong she says the new number out loud.
For streamers and podcasters
Pick a co-host and go live
The studio runs in a browser: your camera on one side, your co-host on the other, with a live voice, lip sync and on-screen tools, and the finished episode recorded at the end.
We're proving it with Cass on our own show, then opening the studio and a first cast of co-hosts to a handful of streamers and podcasters.
Stream or podcast and want a co-host? Tell us about your show and the kind of co-host it needs.
[email protected]About
sofyane founded Counterparty in 2026 as an independent project, builds the studio and its co-hosts, and hosts the first show.
Counterparty builds live AI co-hosts. Independent and self-funded, based in Australia, founded September 2026.
Streamers, podcasters, press and sponsors: [email protected]