Cohost onboarding

What a cohost does before, during, and after the show.

Thanks for cohosting Signals & Subtractions! Read the open part of this page once before your first episode. Everything folded below it is reference, so open a section when you need it rather than reading it through.

On the day, work off your own start-here page, not this one. It carries only your episodes and a tickable checklist for each, it is generated from the show data, and it is refined episode to episode, so it is always more current than prose. This page exists to explain the handful of things a checkbox cannot carry.

The role in one paragraph

You are a rotating cohost. You bring your audience and your perspective. You are not a guest, not a sidekick, not a hype person. You bring one signal worth watching and one subtraction worth making. You hold space for the guest. You backstop Sam if anything goes sideways. You promote the show to your network because you have a stake in it.

The one assignment

Before every episode you cohost, you bring two things:

One signal. Something you are tracking right now in your field. Specific. Concrete. Not "AI agents are getting smarter." Yes "I rebuilt our intake flow around a small local model last Tuesday and these three things broke." First-person and recent.
One subtraction. Something you decided to stop, kill, or refuse to engage with. Yours, not Sam's, not what's trending on LinkedIn. The thing you stopped doing this month and would tell a friend over coffee.

Send both as bullet points to Sam by Tuesday end-of-day so the run-of-show can lock. Two sentences each is fine. Not sure how to generate them? The fifteen-minute method: https://sigsub.show/find-yours

Four slots on air are yours

The segment order and every timing target live in segments/README.md, which owns them. The per-episode run of show Sam sends is what actually governs the tape, and where the two differ, the episode's run of show wins. What that file does not tell you, because it is about the show rather than about you:

Four slots are yours: your signal, your subtraction, your bad joke or funny story near the top, and your close. Come with all four ready. The close is the one people improvise and regret: where to find you, one ask, one URL.
Guest goes first on both the signal and the subtraction turn. That is deliberate and not a slight to you; the guest's material is what the audience came for and the hardest to recover if the clock runs out.
The subtraction is the one turn that cannot be skipped. If the clock goes sideways, that is what gets protected and something else gets cut.
Timings are targets, not rules. A discussion that runs long because it is good is not a problem. Do not watch the clock; Sam does that.

Three things behind the checkboxes

Why the guest-outreach step matters, if you are cohost-of-record for the guest. The booking email (template in booking.md) carries the prep doc at https://sigsub.show/prep and asks the guest to reply "agreed" to the guest terms at https://sigsub.show/guest-terms. That reply is the record that they agreed, which is the thing that matters later, and an episode cannot ship without it. So stay politely on them until it lands, and tell Sam when it does so it gets logged.
The session link comes from Sam 24 hours ahead. Riverside or Ecamm depending on the episode, chosen around what the guest and cohost prefer. Both are browser links, and neither works from a phone.
From the moment you join, treat it as on-air. Recording starts when the session opens, not when the show does, and we chat for a few minutes while people filter in. That warmup is not the show start for the Friday episode, but it is on tape.

Conversation rhythm, chat moderation, and the sponsor segment

Your rhythm in the conversation:

Ask questions that stimulate discussion
Gently refocus the conversation when it drifts
Respond to chat activity if you can see it; let Sam handle it if you cannot
Help the guest look good and feel heard
Keep things playful but professional. Real people, real conversation, serious topics
Defer to Sam when transitions happen. Do not talk at the same time

Your opinion is highly relevant. It should not dominate. The guest's voice gets the most room. Yours is the second-most-important voice in the room.

The sponsor segment. A placeholder segment may run, and it may feature your product if Sam and you decide it fits the episode. It is not automatic. If a segment runs, stay on it, do not talk over it, and let it be short.

No news segment (retired 2026-07-20). Any what-happened-this-week riff stays in the livestream banter and never reaches the episode.

The recording notice. Sam runs the recording reminder in the cold open: viewers see the livestream is being recorded, and anyone joining on-camera is reminded that everything from that moment is captured. You do not need to repeat this. If a guest asks mid-show whether something is on the record, the answer is yes, from join to disconnect on either platform.

Chat moderation across multicast. The show streams to YouTube reliably, and to Substack Live and LinkedIn Live when the multicast path is working (unreliable since 2026-07-28; ops/README.md carries the current state). Each destination has its own chat and Sam cannot watch all of them.

Pick one chat surface to keep an eye on (YouTube is usually the most active). Skim, do not deep-read.
Surface anything actionable in the session side-chat: a great question worth pulling on, a troll worth banning, a name worth shouting out.
Do not engage trolls on-camera. Flag and move on; Sam or the platform's own moderation handles deletion and bans.
If the chat goes sideways on a platform you are not watching, Sam will adjust on the fly.

If Sam drops, you are now the host

It happens. Power blip, network failure, sudden tech failure. If Sam disappears mid-show:

Acknowledge it briefly. "Looks like Sam dropped, give me a second."
Continue the conversation. Keep the guest engaged. Reference where you were in the run-of-show.
If Sam is gone for more than 3-5 minutes and the guest is alone with you, you may continue if you wish. Whenever you are ready to wrap to a natural closing point, thank the guest, point to https://sigsub.show, sign off. But do NOT let the guest drop until their upload has finished, or we may have to re-record.
The show goes on with what you have. Recording continues. We can release a "Sam dropped, the show went on" episode and that becomes its own moment.

Don't panic or apologize repeatedly. Do not go silent. Follow the plan, or do what you want.

After the show

The steps are on your start-here page: reshare Sam's thank-you, look at Thursday's cut, post the episode link Friday, like and reshare the Sunday newsletter. Two things worth understanding rather than ticking:

Thursday's cut is a courtesy review, not sign-off. Flag anything wrong or off and it gets looked at; factual errors always get fixed. The final edit is Sam's call. Tell your guest exactly that when they ask, and never promise them approval, because that promise is the one that turns into a problem in week three.
Friday is also when the livestream recording is retired. From Friday on, the episode is the version people find, so it is the link to send.

You are not required to do all of it. The bias is: post when the content earns it, skip when it does not. Authenticity beats volume. And if a clip Sam posts later in the week would land with your audience, share that too.

What NOT to do

Do not abbreviate the show externally. "Signals & Subtractions" is the only external form; "SigSub" is internal shorthand for this repo and our own conversations, and "S&S" is never used anywhere.
Do not name unconfirmed cohosts or guests publicly. The roster locks one episode at a time.
Do not pitch a sponsor outside the sponsor segment of the show. People get weird about this.
Do not bring a signal that is just "look at this cool tool." We have a higher bar.
Do not bring a subtraction that is generic ("stop doomscrolling"). Make it yours and specific.
Do not dominate the conversation. The guest gets the most air.
Do not improvise major format changes on the fly. Please surface them to Sam beforehand, so he can accommodate them better.
Do not go off-record for the wrong things. Assume everything from join to disconnect is recorded.

FAQ

What if something goes wrong on air? Don't panic. Mention it calmly. You are likely still being seen, heard, and recorded even if it doesn't feel that way.

What if I get kicked out? Rejoin at the same URL Sam sent. Apologize once. Move on.

Why do I hear an echo? Plug in your headphones. Turn off any other speakers connected to your device. If you've done that and still hear echo, stop talking for a few seconds and let the platform's echo cancellation catch up.

Do I have to wear headphones? No, but you have to have them within arm's reach, fully charged, and ready to go in :30sec or less.

What about clothes and appearance? Comfortable but professional. Whatever you would wear to a conference. We are a SFW show; many people watch during the workday.

What about politics or religion? Off-topic. Not because they don't matter, because they are not the show. Keep the editorial focus on signals worth watching and subtractions worth making in AI and the work it changes.

Can I dial in by phone? Nope. Both platforms are browser-based. You need a real computer with a real browser.

Where will this be shared? Live on YouTube, and on Substack and LinkedIn when multicast is working. The episode Friday on YouTube. Sunday newsletter on Substack and LinkedIn. The episode is also an audio podcast, listed on Apple Podcasts, Spotify, and Pocket Casts, plus a video podcast on YouTube; every listen link is on https://sigsub.show.

How long does the livestream stay up? The recording is shared until the Friday episode is released, and then the episode replaces it. Nothing is deleted, but after Friday the episode is what people find. Say this to your guest during the 48-hours-before call, so they point their network at Wednesday if they want the live thing.

What does the guest get to say about the edit? They see the cut Thursday and can flag anything. They do not get approval, and you should never imply otherwise when you book or prep them. The line is: "You will see it before it goes out, and if something is wrong we will fix it. Sam makes the final call." Factual errors and anything genuinely damaging come out. A guest wanting a re-cut because they thought of a better answer afterward does not.

Can you help me with my tech setup? Yes, but ask before the morning of the show. If your episode is on Riverside, it has its own help docs: https://riverside.fm/support

Something is broken the morning of the show. Text or email Sam directly. We will not catch a help-desk ticket in time.

Bright ideas?

This document is a work in progress. If a change would make it better, say so. Email hey@sigsub.show or tell Sam directly. The checklist on your start-here page is the part that changes most; suggest edits to it and every cohost gets them at once.