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 fire a redstone pulse. Everyone else gets a denied signal.

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 is as tough as the block it's named after: same 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 and adjustable.

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 already up, then place it. Linked readers accept a card the moment it's registered on either one, and honor a block on either too — handy for a front and back door that should always agree. Everything else stays independent: owner, mode, frequency, signal length.

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 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. Advanced sensors also take dye, all 16 colors, with a gold nugget to strip it back.

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.

Manager & Member Access Cards

For handing out access at scale. 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.

Estate & Golden Keycards

Two master cards, differing only in reach. The Estate Keycard covers your own builds: right-click to activate — the first click asks to confirm, a second within five seconds binds it to you — and from then on it operates and arms register mode on every reader you placed, and does nothing on anyone else's. The binding lives on the card, so it keeps working even after you hand it to someone else.

The Golden Keycard is the skeleton key with no such limit. It operates any reader regardless of ownership, and arming register mode with it lets you wipe a reader's registrations entirely — with a confirmation step, so it takes two deliberate clicks. Creative-only for now.

Create integration

With Create installed, readers and sensors answer to its wrench. Standing use opens the link screen: give the device a frequency and its accept signal travels wirelessly over a Redstone Link network. A reader picks how it sends — Normal for the physical wire, Link for wireless only, or Mixed for both at once, so the door at your feet and the contraption three hundred blocks away react to the same swipe.

The same screen is where you set how long that signal runs. Hold right-click on the number display to bring up a scale in ticks, seconds, or minutes, slide to the length you want, and release. Sneak-clicking with the wrench picks a device straight into your inventory instead of breaking it, after a confirmation click.

Entirely optional — readers behave exactly as before when Create isn't installed.

The small stuff

• /dynamickeycards transfer <player> hands a reader you own to someone else, registrations intact
• 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.

• 0.1.5 — 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 pulse 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