Mary Jane Knows
ESGet notified

Mary knows which flower is yours.

Mary Jane Knows is a desktop app that watches your favorite online stores, compares every flower with your taste using terpenes measured in a lab, and tells you which one to buy. Every flower you log makes it more yours.

Tell me when it is readySee how it works

Coming soon · Linux first

5 entries · your logbook is 50% of your profile

0121% THC
Jh
Jack Herer
Smells like fresh herbs and pepper
Terpinolene43%Caryophyllene20%Pinene10%
CreativeFocused
Green Door · IndoorOct 12, 2026
0219% THC
Dp
Durban Poison
Smells like fresh herbs and mango
Terpinolene46%Myrcene13%Pinene13%
FocusedDry mouth
Green Door · IndoorOct 4, 2026
0320% THC
Sl
Super Lemon Haze
Smells like fresh herbs and pepper
Terpinolene34%Caryophyllene20%Myrcene14%
CreativeHungry
Green Door · IndoorOct 5, 2026
0418% THC
Tr
Trainwreck
Smells like fresh herbs and mango
Terpinolene29%Myrcene18%Caryophyllene14%
Relaxed
Green Door · IndoorOct 8, 2026
0519% THC
Bd
Blue Dream
Smells like mango and pine
Myrcene35%Pinene34%Caryophyllene16%
RelaxedHungry
Green Door · IndoorOct 10, 2026

Example labels, drawn the way the app prints them. For adults 21+, where it is legal.

Your logbook is what makes Mary better.

At first Mary only knows what you told her. Every time you write down how a flower went, the suggestions lean less on that and more on what really happened to you. It is the most important part of the app.

What your profile is made of

No entries0%
5 entries50%
15 entries75%

Your logbookWhat you said at the start

  • It takes a minute

    A rating, the good and the bad effects, and the method. Blind, without seeing the number.

  • It weighs more every time

    With 5 entries your logbook is already half of your profile. With 15, three quarters.

  • Recent counts more

    Taste changes. An entry from a year ago weighs half of one from today.

  • Mary answers for it

    The app keeps what it predicted before you rated, and shows you how often it was right.

Behind every match, 167,381 lab tests.

The app carries a lab index of 14,723 strains, built from public data: the State of Nevada’s laboratory results library, Smith et al. 2022, Cannlytics and the Connecticut registry. It travels with the app: no account, nothing in the cloud.

In your library
Sativa19% THC
Jh
Jack Herer
Fits you · 97%$8.9/g
New
Sativa19% THC
Dp
Durban Poison
Fits you · 91%$9.1/g
2 options
Sativa20% THC
Sl
Super Lemon Haze
Fits you · 88%$8.6/g
Hybrid18% THC
Tr
Trainwreck
Fits you · 84%$7.4/g
Hybrid19% THC
Bd
Blue Dream
Match 58%$8/g
Sativa17% THC
Ta
Tangie
Match 52%$10/g
2 options
Hybrid22% THC
Ma
MAC 1
Match 44%$12/g
Hybrid24% THC
Wc
Wedding Cake
Match 41%$11/g
Hybrid25% THC
Ru
Runtz
Match 36%$13/g
Indica28% THC
Gm
GMO
Very high THC
Indica17% THC
Pp
Purple Punch
Blacklist
Hybrid
Mm
Moon Mango
No data$9/g
An example: what your stores have today, if you like Jack Herer.

Everything visible, everything informed.

One card per strain, like an element in a table. You read a whole store at a glance, and every part of the card means something.

What each part says
  1. 1

    Options

    The same strain in another size, brand or lot is one card with several options.

  2. 2

    Type and THC

    What the store says, and the THC of the lot. “≈” when it is the typical value of the strain.

  3. 3

    Two letters

    In the color of the dominant terpene.

  4. 4

    The bar

    The terpene profile. Each terpene always has the same color.

  5. 5

    The match

    Calculated by the app. When it fits you, the card says so in words.

  6. 6

    The price

    Per gram, for the cheapest size, in the store’s own currency.

The five states of a card
  • Sativa19% THC
    Dp
    Durban Poison
    Fits you · 91%$9.10/g

    Fits you75% or more, on solid data

  • Hybrid19% THC
    Bd
    Blue Dream
    Match 58%$8/g

    NeutralHas data, under 75%

  • Indica28% THC
    Gm
    GMO
    Very high THC

    Not for youDiscarded, with the reason

  • Indica17% THC
    Pp
    Purple Punch
    Blacklist

    BlacklistYou never want to see it

  • Hybrid
    Mm
    Moon Mango
    No data

    No dataNobody has measured it

One color per terpene, from its aroma
  • Myrcenemango, earth
  • Limonenelemon
  • Caryophyllenepepper
  • Pinenepine
  • Linaloollavender
  • Humulenehops, wood
  • Terpinolenefresh, herbal
  • Ocimenesweet, floral

The color never goes alone: it always comes with the name.

Seven things Mary does for you.

This is a drawing of the app, with example data.

Your settings

Stores

Green Doorgreendoor.example · 180 flowersMXN×
High Desert Flowerhighdesert.example · 94 flowersMXN×
La Esquinalaesquina.example · 71 flowersMXN×
greendoor.example/menu
Add
Reading the menu…

Paste the address of your store or of its online menu. I check them every 6 hours.

Flower only: 212 other products left out

A card-shaped label for Jack Herer: the letters Jh, 21% THC, smells like fresh herbs and pepper, three terpene bars, three effects, the store and the date.The same label as a strip, with the letters in a black block.
Card · 50 × 62 mm · Strip · 62 × 29 mmAn example, exactly as the app prints it.

Take the card to the jar.

Any strain prints as a label, in plain black and white, to stick on the jar where you keep that flower. Two sizes to choose from.

What it carries, and what it leaves out

  • What it carries

    The two letters, the name, your library number, the THC, the aroma and the three main terpenes, with the store and the date.

  • What you felt

    If you logged that strain, the label shows the effects you wrote down. They come from your logbook, not from a promise.

  • What it leaves out

    The match and your rating. Seeing them on the jar would sway you the next time you rate it.

  • Two ways to print

    An image made for 62 mm label printers, or a letter-size PDF with a cut line for a regular printer.

Chemistry over folklore.

We read the studies before writing the match. A few things did not survive.

  • Indica and sativa do not predict the chemistry

    The card says “Sativa according to the store”. It is a label, never a promise.

  • No promised effects

    Mary is sure about the aroma. Effects come only from what you wrote in your own logbook.

  • The number is not dressed up

    It is not inflated to look good. When the data is weak it says “Estimated” and the flower is not recommended.

  • No medical advice

    This is a tool to choose flower. It is not medicine and Mary is not a doctor.

The AI does not decide. The math does.

The match is calculated by the app from lab data. The AI is optional and does two things. Everything it does is marked in this purple, so you always know when it is the AI talking.

This is a drawing of the app, with example data.

You pay your AI provider, not us. The app shows the approximate cost before it spends anything.

What the AI does, and what it costs

  • Mary explains

    Ask and she explains a flower in plain words: the aroma, and which of your strains it resembles.

  • Research on request

    For a strain nobody has measured, the AI searches the web and keeps its sources. Only when you ask, and the button says what it costs.

  • Your own connection

    Connect OpenRouter with one click, or use a Claude or OpenAI key. Advanced: Codex or Claude Code with your subscription.

  • Works without it

    Without AI you still have the index, the match, your stores and your logbook.

Your taste stays on your computer.

No account and no cloud. The app keeps everything in one file on your machine.

Stays with you

  • Your profile, your library and your logbook
  • Your stores and what they had
  • Your keys, in the system keychain

Leaves, and when

  • Requests to the stores you added, to read their menus
  • Once a day, a question to mjknows.com: is there a newer lab index? It sends nothing of yours, and you can turn it off
  • When you ask Mary to explain: the flower, your strains it resembles and what you logged about them, to the AI provider you chose
  • When you ask for research: the name of the strain, to that same provider

This site has no cookies and no trackers. Your browser only remembers that you said you are 21 or older, and the theme you picked.

All of it, on the table.

  • Online stores, by address

    Mary Jane Knows is made for stores that sell online. Paste the web address and Mary reads the menu. It works with the online menus of most dispensaries and with shops on Shopify, WooCommerce and Zoho.

  • Flower only

    Pre-rolls, infused buds, loose shake, edibles and concentrates stay out. Smalls and popcorn stay in: they are whole buds.

  • New arrivals

    What came in at each store, each day, sorted by what fits you.

  • Match with reasons

    “Why 91%” shows what added and what subtracted, and where the flower ranks among everything in your stores.

  • The lot, when the store publishes it

    If the menu shows the terpenes of the lot, the match uses those and not the average of the strain.

  • Library and blacklist

    The strains you like, the ones you saved to try, and the ones you never want to see again.

Twelve more things it does

Your stores

  • One card per strain

    The same strain in another size, brand or lot becomes an option of the same card, each with its match and price.

  • Prices as they are

    Price per gram in each store’s currency. Nothing is converted.

  • In the background

    It sits in the tray, checks your stores every 6 hours and sends a system notification when something arrives.

Your taste

  • A lab index inside

    14,723 strains and 167,381 lab tests from public sources travel with the app, and it downloads the newer index when there is one. Most strains need no research.

  • Blind logbook

    The most important part: it is what improves your suggestions. You rate without seeing the number, and the app shows how often it got it right.

  • It learns from you

    Every entry weighs more than what you said at the start, and recent ones weigh more than old ones.

The rest

  • Search

    Any strain, in your stores or in the index. Ctrl/Cmd+K.

  • Start your way

    A full first setup, or skip it and just keep a logbook. In English or Spanish: you switch without restarting.

  • Fix a strain

    If a product was matched to the wrong strain, correct it once and it holds in every store.

  • Backup

    Everything exports to one file. Your keys are not in it.

  • Mary flags the odd ones

    If the lot in the store does not carry the usual dominant terpene of the strain, or a grower sells the same lot under another name, she says so.

  • What the store says

    The effects a store publishes are shown apart, as “The store says”. They do not move the number.

Fifteen years in, I just want flower.

I started late, at 35, with a lot of respect for the plant. A lifelong friend showed me the way. He knew nothing technical, but he knew how to take care of the moment and the place. It came at a hard time in my life, and it helped me see things differently. I never forgot it.

Then I went for more, like everyone: pre-rolls with diamonds, carts, edibles, resin. Everything got stronger. My experiences got worse.

So I went back to flower. Plain flower. I kept refining how I enjoy it, step by step, until the day I finally understood the sommeliers: that flower really did taste like fruit.

Then came the hard part: finding it again. I bought a gram at a time, and when I came back for the one I loved, it was gone. Cross after cross, new names every week, and I did not want to spend my time in the store figuring out which jar was mine.

So I made Mary Jane Knows. She watches your stores, compares every flower with the ones you have loved, and tells you when one that fits you arrives. It is not about more. It is about yours.

Less hype. More flower.

— Maxx Darko

In testing. Almost there.

Mary Jane Knows is being tested right now. We have not decided the price yet: it may be free, or free with paid extras. When we know, it will say so here.

Tell me when it is ready

Or write to [email protected]

One email from us, the day it is ready for your computer. Nothing else. You send it from your own mail, so this button collects nothing.

  • Linux first, then macOS and Windows
  • In English and Spanish
  • No account, nothing in the cloud
  • Flower only