Dynamic Keycards

Redstone, but with a guest list.

Dynamic Keycards adds keycards and card readers to your world — a compact way to put an ID check in front of your redstone. Place a reader and it binds to you. Register a blank card on it and the card becomes a keyed keycard; from then on, that card makes the reader emit a redstone signal. Everyone else gets a denied light.

Supported versions

• NeoForge 1.21.1 — available now
• Fabric support and more game versions are planned

Devices

Card Readers

Five styles to match your build: Insert, Swipe, Touch, Advanced, and Obsidian. They behave identically — only the looks and the recipe cost differ — and mount on floors, walls, and ceilings just like buttons. The Obsidian reader matches obsidian's hardness and blast resistance — diamond pickaxe required.

The status lights show what a reader is doing: off when idle, green for accepted, red for denied, and a blinking display while register mode is armed. A registered card fires a redstone signal at full strength — 3 seconds by default, adjustable from the reader's settings screen on a sliding scale in ticks, seconds, or minutes.

A reader binds to the player who placed it — nobody else can register cards on it. In register mode, one press always toggles exactly the card you're holding: accepted cards get removed, rejected cards get registered. Copies of that card are never affected.

Readers can also be linked to each other: hold an unplaced reader, right-click one that's in register mode, then place it. A card registered anywhere in a linked group is accepted at every reader in it — chain them, star them, link as many as you like — and a card removed anywhere is blocked everywhere. Handy for a front and back door that should always agree. Everything else stays independent: owner, mode, frequency, signal length.

Sneaking with your own keycard cuts an accept signal short and drops straight into register mode, so you don't have to wait out the door you just opened. That's the only thing sneaking is needed for — registering cards and tuning connections work either way.

Card Duplicator

Need five cards that open the same door? The Card Duplicator copies a card onto a blank one: sneak-click it with the source card, then with a blank. The copy inherits everything the source could open at that moment — afterwards the two are fully independent cards, so removing one never locks out the other. No owner, no redstone output. Colors are kept, so differently colored cards can share access.

Sensors

Wall- and ceiling-mounted proximity sensors, in a plain and an advanced tier. They watch their own cell and the one below for living entities and hold a redstone signal for as long as something's there — continuous, not a fixed burst like a reader's — with a release delay you can set down to zero. No ownership, so anyone can adjust or move one.

The advanced tier's detection range is yours to shape. Right-click it with redstone dust and a red-edged box appears; Ctrl+scroll toward any face to push or pull that side a cell at a time, then right-click to commit. The full reach is a 3×3×3 volume — hanging below a ceiling sensor, or projecting out and down from a wall one — and any smaller box inside that works too.

The advanced tier can be bound to a card reader: hold one, right-click the reader, and place it. From then on, anyone walking past carrying a card that reader accepts — anywhere in their inventory, not just in hand — triggers the reader remotely, sound and lights and all. Automatic doors that still check ID.

A bound sensor picks how the two share the signal: the reader alone, both at once on the reader's own timing, or both on the sensor's. The same gesture binds one advanced sensor to another instead, and the two drive each other — one connection per sensor, so aiming at something already bound is refused rather than quietly rewired. Advanced sensors also take dye, all 16 colors, with a gold nugget to strip it back.

Transmitter & Receiver

A pair that carries a redstone signal across any distance without wiring between them. A transmitter broadcasts whatever wired signal reaches it. In mixed mode it can also be triggered by hand: one right-click sends a signal that runs for a length you set. A receiver turns that back into its own output somewhere else entirely: Pulse mirrors the source live with an optional release delay, Toggle flips on at each trigger and stays on until the next. Full 0–15 strength survives the trip, so comparators work on the far side.

A receiver doesn't need a transmitter, either — it can take a card reader or an advanced sensor as its source directly, putting an accept signal anywhere in the world. Binding works as it does everywhere else here: hold the unplaced receiver, right-click the source, then place it. Neither device has an owner, except a receiver listening to a reader — that one inherits the reader's lock for as long as it's tuned to it.

Siren

A rotating warning light for the moment a door opens — or fails to. It turns while a redstone signal reaches it, or while a device it was bound to is running; bind it before placing, to a reader, a transmitter, or an advanced sensor, the same way a receiver binds. Three sound modes sit alongside the light, and both the turn speed and how long it keeps running are adjustable.

Cards

Blank Cards & Keycards

Craft a Blank Card in any of the 16 dye colors. Registering it on a reader stamps it with a unique key and turns it into a Keycard — keyed and unkeyed cards are visually distinct, so you can tell at a glance. Craft any card with a dye to recycle it into that color's blank card.

With Curios or Accessories installed, cards go in the necklace slot — any of them, golden and estate included. Right-clicking a reader standing and empty-handed then passes with the card you're wearing. Registering, removing and resetting still want it in hand.

Manager & Member Access Cards

A Manager Access Card's registrations also apply to every Member Access Card it issued — register the manager once, and the whole set passes; unregister it, and the whole set is shut out. Issue members by duplicating the manager onto blank cards, or clone a co-manager onto a blank manager card. Members are pure pass tokens — they can't be registered or duplicated; all control goes through the manager. Manager cards have no player binding: possession is authority.

Master Cards

The Golden Keycard is the master card. It works with any reader, regardless of ownership: it opens them, arms register mode on them, and can wipe a reader's registrations entirely — with a confirmation step, so it takes two deliberate clicks. Creative-only.

The Estate Keycard does all of that too, but only on readers you placed yourself; on anyone else's it does nothing. Right-click to activate it — the first click asks to confirm, a second within five seconds binds it to you. The binding lives on the card, so it keeps working even after you hand it to someone else.

Both have a maintenance-tier counterpart, swapped 1:1 on a crafting table with the binding intact. Where keycards handle passing and registering, maintenance cards handle configuring: they open a device's settings screen and pick devices up. The golden one does it on anything; the estate one covers the readers you placed and whatever's linked to them, plus every device that has no owner to begin with — transmitters, standalone receivers, duplicators.

Create integration

With Create installed, a wrench opens the same settings screens a maintenance card does, and those screens gain two Redstone Link frequency slots — so an accept signal can ride a network you've already built, alongside this mod's own transmitter and receiver. A reader picks how it sends: Reader-Only for the physical wire, Link-Only for wireless, or Simultaneous for both at once, so the door at your feet and the contraption three hundred blocks away react to the same swipe.

Connections survive being copied, too. Every device carries a stable id rather than a coordinate, so a schematic that prints a linked set wires the copies to each other, while a link that pointed outside the print still points at the original.

The small stuff

• /dynamickeycards transfer <player> hands a reader you own to someone else, registrations intact; release drops its owner entirely, leaving it to the golden cards. /dk and /dks work as shorthands
• Every device is built around a DK Chip, the mod's one crafting component
• Distinct note-block tones for pass, register, remove, and deny — you can hear the result without watching the lights
• EMI: registering and duplicating show up as recipe categories in the recipe browser
• Jade: readers show their owner and register-mode state at a glance
• Signal length and the per-reader registration cap are configurable
• Hold Shift on any item for a quick rundown of what it does
• Supported languages: English, 한국어, 日本語, 简体中文, Deutsch, Español, Nederlands
• Vault doors, elevators, crew quarters, rentable rooms, trap corridors — anything a button can drive, a reader drives with standards

Changelog

Full details in the changelog on GitHub.

• 0.1.9 — Siren; wearable cards via Curios or Accessories
• 0.1.8 — Transmitter and Receiver; golden and estate maintenance cards; DK Chip; sensor-to-reader signal modes; links survive being copied; consistent signal-mode names
• 0.1.7 — Multi-reader link groups; adjustable sensor detection range; register mode can interrupt a running signal
• 0.1.6 — Sensor-to-sensor binding
• 0.1.5 — Sensors; advanced sensor–reader binding and dyeing; reader-to-reader linking; Mixed signal mode
• 0.1.4 — Signal length adjustment in the link screen; wrench pickup now asks for confirmation
• 0.1.3 — Obsidian Card Reader; Create wrench integration and Link Mode; renewed card textures
• 0.1.2 — Configurable signal length; reader ownership transfer command
• 0.1.1 — Estate Keycard; Manager Access Card recipe rebalance
• 0.1.0 — New Blank Card recipe; member cards fully pass-only; golden reset now asks for confirmation
• 0.0.9 — Feedback tones, Jade support, plain-language descriptions
• 0.0.8 — Naming corrections; EMI recipes for every color
• 0.0.7 — EMI recipe-viewer integration
• 0.0.6 — Card family rename; every item type in the creative tab
• 0.0.5 — Blank cards split from keycards
• 0.0.4 — Manager & member cards, co-managers, registration cap config
• 0.0.3 — Snapshot-fork duplication, per-card register/remove toggling
• 0.0.2 — Card Duplicator, unregister, golden full reset, user manual
• 0.0.1 — Initial release