You're at the tent with gloves on, and you have three questions. What's due today? Where do I log this flush? Did that bag ever get its first harvest? The answers are already in Hypha, spread across the Schedule tab and your blocks' timelines.

We're building Rhizo so you can ask questions like those and get answers from your own farm's records. Read this as a dev log, not a launch post. Right now, our team is testing Rhizo on our own farms. It isn't available to growers yet, and we haven't set a date.

What is Rhizo?

Rhizo is an AI assistant we're building into Hypha. In our testing, it answers three kinds of questions: how to do something in the app, what's going on with your farm, and general growing questions. It opens from the button in the top-left corner of the app, where Feedback lives today. The sheet that opens has Ask Rhizo and Tell the team side by side, so a bug report is still one tap away.

A new conversation on a demo farm we set up for these screenshots. The suggestions follow what's on the farm: with a block fruiting, How do I log a harvest? comes first.

Rhizo is built to look things up instead of guessing. It can read your farm, but it can't change anything on it.

What can Rhizo tell you about your farm?

In our testing, Rhizo can tell you what's due, what stage each block is at, what's been harvested and what's in stock, by looking it up in your records. Its thirteen read-only lookups cover:

Your farm at a glance
Your grow blocks, each block's events and harvests, and a block's climate
Your zones and a zone's sensor history
Which sensors are online
Your reminders and alerts
Your strains, inventory and recipes
Your photo log's details, such as dates and captions, but never the pictures themselves

Rhizo picks the lookups a question needs, and the chat tells you what it's checking while it works.

Rhizo's answer to What needs doing on my farm today? It lists three tasks with times, such as misting and fanning the fruiting tent, and says there are no unread alerts — An unedited answer on the same demo farm, which we re-seeded for this shot, so its tasks differ from the next answer's. Rhizo checked the reminders and the alerts before it wrote a word.

Bigger questions take more lookups. When I asked about the blue oyster bags on that demo farm, Rhizo made nine lookups before it answered. It listed the grow blocks and strains, opened each bag and checked the photo log, then the zone's history, the alerts and the reminders. Its answer named each bag, when it started, the 412 grams logged from the first flush, and what's scheduled next.

Composite: three status lines from one answer, Opening a grow block, Checking a zone's history and Checking your reminders. Below them is Rhizo's answer about Blue Oyster bags A and B — A composite from one answer on the same demo farm. The chat shows one status line at a time; we stacked three of them above the answer. Hypha Aeris, the sensor Rhizo mentions, isn't for sale yet; reservations are planned for 2027.

Each of those status lines comes straight from the code. Every lookup Rhizo can make is one line that registers it, and the second phrase in quotes is exactly what you see while it runs.

A code editor window listing thirteen Python register_tool lines, one per lookup, each pairing a lookup's name with the status line it shows, such as list_reminders with Checking your reminders — All thirteen lookups, straight from Hypha's backend. Each one is read-only.

How does Rhizo help you use Hypha?

Rhizo answers "how do I…" questions from 49 short guides we wrote against the app's real buttons and screens. When the right steps depend on your farm, it looks first. Ask how to start a grow block before you've added any strains, for example, and it starts with how to add one.

Rhizo's answer to How do I log a harvest? It explains that harvests are logged on the block's timeline, then gives five numbered steps ending with Save the flush — The steps use the app's real button names, including the catch that a block has to be fruiting before you can log a harvest.

A guide that names a button the app doesn't have is worse than no guide. So a test checks every label and menu path in all 49 guides against the strings the app actually shows on screen, letter for letter. If someone renames a button and forgets the guide, the test fails the next time our backend tests run.

A code editor window showing test_app_guide.py lines 132 to 145. The test collects every string the app renders and asserts that no guide label or menu path is missing — The test that keeps Rhizo's guides honest. Its last line, assert unknown == [], means no guide may name a label the app doesn't show.

Rhizo can still slip. Under its latest answer, "Send to team" opens the Tell the team tab with that exchange already filled in, so you don't have to explain it twice.

What does Rhizo say about growing in general?

Rhizo gives general growing advice, and it says up front that the advice is general, not read from your farm. It covers the whole method, typical ranges and what they depend on. When heat, pressure or chemicals come up, it's set up to add a safety note.

Rhizo's answer to How do I sterilize grain jars in a pressure cooker?, shortened. It opens with This advice is general, not read from your farm. It ends with the pressure, a time range and a safety note about letting the cooker depressurize — Shortened: the dots mark where we cut how to prepare and load the jars. Every word you see is Rhizo's.

What does Rhizo do when it doesn't know, or shouldn't answer?

Rhizo is built to say when it doesn't know and to stay out of safety calls. Ask about the humidity in a tent with no sensor, and it says there are no readings rather than inventing a number. Its instructions tell it to decline edibility checks, wild mushroom IDs, and medical or legal advice. They also tell it never to give a grow an "all clear": contamination calls stay yours. It's AI, and instructions aren't guarantees, so treat its answers as information, not advice.

Two separate exchanges. Rhizo says it couldn't find humidity readings because no sensor is placed in the fruiting tent. Asked whether wild white mushrooms with a ring and a cup are safe to eat, it declines and points to a local mycological society or an expert — Two separate conversations on the same demo farm. No sensor, no number, and no edibility calls on wild mushrooms. Our own rule is blunter: don't eat a wild mushroom unless an expert has identified it in person.

Every answer Rhizo writes carries the label "AI-generated · can be wrong," and the latest one has Helpful, Not helpful and Report buttons right under it. Reports come straight to us.

How are we keeping your data private while we build Rhizo?

Rhizo asks for your OK before your first question, and it tells you what it sends to answer you. It never sends your photos. Your conversations aren't used to train AI models; we test Rhizo with questions we write ourselves. We'll spell out the full details, and update our Privacy Policy, before anyone outside our team can use Rhizo.

Some of our privacy rules are enforced in code, too. One is that the text of your conversations stays out of our logs and error reports. In one test, a made-up "canary" word goes into the question, a lookup's result and Rhizo's answer. The test runs that conversation normally and three ways it can go wrong partway: the answer breaks off, a lookup crashes, or the AI service rejects the request. If the canary turns up in any log line or error report, the test fails.

Will Rhizo work on team farms?

We're testing Rhizo on shared team farms too, and a switch in the farm's settings lets its Owner turn Rhizo on or off for the whole team. Your teammates can't see your chats with Rhizo. Whether team farms get Rhizo when it opens up isn't decided yet.

How are we testing Rhizo?

We test Rhizo against a fixed set of questions we wrote ourselves, and any change to its instructions or guides has to pass them again before it can reach growers. The set covers how-tos, farm data, general growing, food safety, medical and legal questions, and things it should say it doesn't know. It also includes tricks, like a grow note that tries to give Rhizo orders. Rhizo treats your notes as data: it's set up to report what a note says, not to follow instructions hidden in one.

Why is it called Rhizo?

Rhizo is named after rhizomorphs, the cordlike strands some fungi grow to seek out food and soak in water and nutrients (University of Utah). That's the job: reach into the corners of your farm and bring back an answer.

The Hypha logo turning into Rhizo. The big mushroom becomes the core, the small one becomes the orange node, and the circuit traces become its arms.

The avatar went through five concepts before this one won. In the app, the animation is drawn in code rather than played from a video, so it stays sharp at any size.

Ring, logo, circuit, core: four paint calls per frame. On the last frame, it hands off to the still avatar.

When can you try Rhizo?

You can't try Rhizo yet: it's in testing with our team, and we haven't set a date. We're also experimenting with letting it open the right form already filled in, so you can check it and press Save. Before Rhizo opens up, it has to keep passing our tests, run reliably for a good long stretch, and clear privacy and app store reviews.

We'll post here when it's ready. In the meantime, I'd love to know: what would you ask Rhizo first? Email team@demetermycolabs.com. Those emails help us decide what to teach it next.

— Derick

Dev log: meet Rhizo, the assistant that reads your farm