1
Play as normal
CrateMate reads your DJ software's history. With Serato it shows two decks: what's On Air and what you've just cued as Next. With rekordbox it shows the track you're playing, once rekordbox has logged it.
For open-format DJs · Mac beta
Never play the same set twice.
Long sets burn through the same songs. CrateMate sits beside Serato or rekordbox and brings back the ones you own but haven't played in a while, and shows you exactly when you last played each one.
Works with Serato DJ and rekordbox on Mac, together if you use both. Your library stays on your Mac.
Songs you forgot you hadTracks from your own library that haven't had a spin in a while, ready when you need a fresh idea.
Last played, at a glanceEvery row shows how often and when you last played it, so you never repeat last night by accident.
Your call, alwaysIt brings ideas. You bring the taste, the crowd-reading and the final say.
How it works
Deck to deck in three steps.
Set up once. After that it just sits there, ready when you need an idea.
2
Tap the deck, set the range
Serato can't tell which deck is audible, so you tap the one to mix from (rekordbox shows one track, so there's nothing to choose). Then choose how tight the tempo match should be.
3
Spot something you forgot
Scan the list, check when you last played each song, then drag one onto a deck. Not for tonight, or ever? One tap sends it to Do Not Play.
A night with CrateMate
Built for the long sets.
Open-format DJs play more, for longer, to crowds that want everything. Here's where it earns its place.
9:40pmFriday. Set five of the week.
Your hands know what's next.
You've played this crowd all week. The next ten songs are already in your fingers, and most of them are the ones you played last night. It's not a bad set. It's just the same set.
11:15pmHalfway through five hours.
Fresh ideas, from your own library.
The corporate crowd is up and you need new options without leaving the vibe. CrateMate lists songs you own that fit what's on, and each row shows when you last played it. Not played in months? Never played at all? That's the one to try. Tap P on the ones you like and they wait in your Prepare list, even after the suggestions move on.
12:30amThe request.
Never lose the thread.
Someone asks for a song you hadn't planned and it's nothing like what you were building. You play it, because that's the job. Now where do you go? Load it, tap the deck, and CrateMate suggests tracks with a similar vibe, so the night keeps flowing.
1:50amThe one you forgot.
"Oh, I own that."
A song you bought years ago and never got round to playing. It fits, it's a left turn, and the room has never heard you play it. You drag it on and the floor reacts. That's the whole idea.
Not a replacement for your creativity. A reminder of everything you already have.
Prepare list
Shortlist as you play.
Tap P on any suggestion and it joins your Prepare list. The suggestions move on as you mix. Your shortlist doesn't.
Drag from it onto a deck when you're ready, or save it as a Serato crate to pick up next time.
Last played
Every row remembers.
Not played in months, played twice, played every night this week. You see it before you drag it on, so you stop defaulting to the same songs.
- Never playedOwned, never tried. Fair game.
- Played once · last 3 MarEight months since it last had a spin.
- Played 14× · last 6 NovLast night's favourite. Maybe not tonight.
The key rule
Three chips. One question: will it blend?
Once a song is in the right neighbourhood for vibe, the chips tell you if it will blend with the track you're about to mix into.
8A✓
Fits
Same key, one step either way, or the relative major or minor. Safe to blend.
- 8A → 8A same key
- 8A → 9A, 7A one step
- 8A → 8B relative
10A↗
Energy shift
A deliberate lift. Plus two on the wheel, or a semitone change. You decide if tonight needs one.
- 8A → 10A energy +2
- 8A → 3A energy +7
4B≠
Key clash
The keys don't match. Plenty of DJs mix these on purpose, so they stay in the list, ranked after the keys that fit. Your ears, your call.
- Hollow grey chip with ≠
- Always the words too, never colour alone
Vibe firstSuggestions start from songs that sit close to what you picked, then tempo and key decide the order. Half and double time count as a tempo match.
Freshness is on every rowThe meta line shows how many times you've played it and when you last did, so you can lean towards the songs that need a spin.
The window
Learn the window in a minute.
A narrow window that sits above your DJ software. Big targets, built for a dark booth.
● Serato live1
On air · 2:41
Midnight Signal
Kline
123
9A
3✓ Fit9A → 8A · tempo locked
2
Next · Deck 2
Glass Harbour
Oda Vane
124
8A✓
4
Search crate
Filters
Up next24 from your crate
- 1
On Air
The track you're mixing out of, with time remaining. Its key chip stays neutral because there's nothing to compare it with.
- 2
Next
The track you've just cued. Its chip shows whether the transition from On Air works: Fits, Energy shift or Key clash.
- 3
Mix-check strip
One line that answers "does what I've loaded actually work?" Key move, tempo lock or BPM difference.
- 4
Search and Filters
Search your crate, then narrow the list by key and tempo range.
- 5
Suggestion rows
Key chip, title, and a meta line with the key move, BPM difference, how often you've played it and when you last did. Drag a row onto a Serato deck to load it, or tap P to keep it in your Prepare list.
- 6
Do Not Play
One tap, no confirmation. The row collapses with a few seconds to undo, then that track is never suggested again.
Also in the box
Small things that matter mid-set.
±
Tempo range slider
From ±3 to ±16 BPM, right on the main screen. The list re-ranks instantly.
⇄
Crate or everything
Show only what you own, or include ideas you don't have yet for crate-digging.
▲
Always on top
Pin a compact window above Serato or rekordbox so you never alt-tab mid-mix.
◐
Night, Day or Auto
Dark for the booth, light for daytime sets, or follow your Mac's appearance.
P
Prepare list
Tap P on any suggestion to shortlist it. The list stays put while the suggestions change, and you drag from it onto a deck when you're ready.
♪
Playlists via Claude
Connect Lexicon through Claude Desktop and ask for playlists built from your own library.
Built by an open-format DJ
Made for the set, not the demo.
CrateMate started as a tool for James Campbell's own open-format sets: a 49,000-track library and a lot of long nights where the same favourites kept coming round. It's still tuned on real gigs, from Ibiza clubs to ships at sea.
17years behind the decks
5Ibiza seasons
23Virgin Voyages contracts
Serato and rekordbox, together.
Use both and CrateMate joins your libraries and follows whichever one you played a track in last. Other DJ software is planned, one reader at a time.
Serato DJ Works now
rekordbox Works now
VirtualDJ Up next
djay Pro After that
Invite-only beta
Get on the Mac beta.
I'm letting DJs in a few at a time, so I can look after every tester. Tell me what you play on and I'll be in touch if you're picked.
What you'll need
- A Mac running a recent macOS (Apple Silicon or Intel)
- Serato DJ or rekordbox, with your library on that Mac or a connected drive
- For rekordbox: one setting changed in rekordbox so it logs tracks sooner (CrateMate shows you which)
- An internet connection for new suggestions
What beta testers get
- Free access. Codes last 30 days, extended while we're still testing.
- A direct line to me in a WhatsApp community for testers.
- Fast fixes. Tell us what's wrong and it gets sorted quickly.
You're on the list.
Thanks. Check your inbox for a quick confirmation. If you're picked, I'll email you your access code.
FAQ
Straight answers.
How does the beta work?
It's invite-only. Sign up and I'll pick testers in batches, then email you an access code and an invite to the testers' WhatsApp group. Access is free. Codes last 30 days, and I extend them while we're still testing.
What happens when the beta ends?
Beta codes last 30 days, and I extend them while we're still testing. When the beta ends, your code stops working and you'll be able to choose a plan to carry on. Nothing is charged automatically.
Who is it for?
Open-format DJs with big libraries and long sets: weddings, corporate gigs, residencies, ships, anywhere you play five hours and a bit of everything. Genre specialists can use it too, but that's who we're building for.
How does it choose what to suggest?
It starts from the track you pick, finds songs with a similar vibe, keeps the ones you own, then orders them by tempo and key. Each row shows how often and when you last played it.
Does it suggest tracks I don't own?
By default it only shows tracks in your library. A toggle adds radio ideas you don't have yet, marked as not in your crate, for crate-digging.
Will it work with my DJ software?
Serato DJ and rekordbox today. VirtualDJ is next, then djay Pro. Each one needs its own reader, so there are no dates yet.
Can I use Serato and rekordbox together?
Yes. Turn on both in Settings. CrateMate joins the two libraries (a file both know shows once, and plays are added up) and follows whichever program you played a track in most recently, so there is nothing to switch on the night.
Do I need to change anything in rekordbox?
One setting. rekordbox only writes a track to its history after it has played for a set time, 60 seconds by default. Lower the Playback time in rekordbox's History settings (1 second works) and CrateMate sees each track almost as soon as it plays. CrateMate never changes rekordbox's settings itself. rekordbox also doesn't say which deck a track is on, so you see one On Air track rather than two decks.
Is my library safe?
No. It reads the folders you choose and keeps its own list on your Mac. Nothing in Serato or rekordbox is altered.
Does anything leave my Mac?
No. Your library stays on your Mac. To find similar music, CrateMate looks up only the track you're seeding from, not your collection.
What if the venue Wi-Fi dies?
Your library and the mixing maths are local. Suggestions you've already looked up are cached, so they still work offline. New lookups need a connection.
Is there a Windows version?
Not yet. The beta runs on Macs, both Apple Silicon and Intel. There's no Windows version yet.
Why does macOS warn me when I first open it?
The beta isn't notarised by Apple yet. Right-click the app, choose Open, and confirm once. You won't be asked again.