Blueprint Share

Send blueprints, blueprint books, deconstruction planners, and upgrade planners between two Factorio instances on the same machine, over localhost UDP. Handy when running a regular save and a map editor side-by-side.

Requires Factorio 2.0 or newer.

Quickstart

Two-way sharing between a Steam copy and a second standalone copy:

1. Get a second copy. Steam runs only one instance at a time. Download a standalone build of the same version from https://www.factorio.com/download (free for anyone who owns Factorio) and extract it outside the Steam install.

   Windows: grab the ZIP package, not the installer. The installer shares %APPDATA%\Factorio with the Steam copy, so only one can run at a time.

2. Use port 25001 for the Steam copy and 25002 for the standalone. Change them only if another app is already using those ports.

3. Set the launch flag on each copy so it listens on its own port:

   • Steam copy - right-click Factorio -> Properties -> Launch Options, enter --enable-lua-udp=25001.
   • Standalone (Linux) - launch from a terminal as ./factorio --enable-lua-udp=25002.
   • Standalone (Windows) - create a shortcut to bin\x64\factorio.exe and append --enable-lua-udp=25002 to the Target field. Or launch from a terminal: factorio.exe --enable-lua-udp=25002.
   • Standalone (macOS):
     • Put factorio.app in its own folder, e.g. ~/Applications/Factorio-Standalone/.
     • Create a config.cfg next to it with the contents below, or download the ready-made macos/config.cfg from this repo:
       ; version=13
[path]
read-data=__PATH__executable__/../data
write-data=__PATH__executable__/../../../factorio-data
     • From that folder, run open ./factorio.app --args -c "$PWD/config.cfg" --enable-lua-udp=25002 (the -c path must be absolute). Factorio will create factorio-data/ alongside factorio.app for saves, mods, and config.

4. On the standalone, set Mod settings -> Per player -> Blueprint Share -> Destination port to 25001. The Steam copy needs no change - its default already points at 25002.

One-way only: Both sides need --enable-lua-udp, but only the receiver's value matters for routing - the sender's value is its source port only.

Usage

• Ctrl + B - Send the blueprint, book, or planner currently in your cursor.
• Ctrl + Shift + B - Toggle the Inbox window. Items received while Auto-receive is off land here. Left-click a slot to put that item in your cursor, right-click to remove it. Larger transfers show a progress bar while they arrive. Capacity is configurable.
• Ctrl + R - Force-drain the UDP buffer. Only needed while the game is paused or in the Map Editor (the auto-poll is suspended in those states). Imports the item to your cursor regardless of the Auto-receive setting.

Settings

Per-player settings live under Mod settings -> Per player -> Blueprint Share. Max transfer size is map-wide - find it under Mod settings -> Map -> Blueprint Share.

Limitations

• Localhost only. No LAN or internet sharing - Factorio binds UDP to 127.0.0.1.
• Very large books may briefly freeze the game. Books of any size transfer fine, and the inbox shows a progress bar while they arrive. Sending or receiving a very large book can pause the game for a moment at each end.
• One transfer at a time. If two items are sent to the same instance at once, only the first goes through.
• Map Editor / paused game. Auto-receive needs the tick running. Either unpause (Tools -> Time -> Speed -> Play) or press Ctrl + R to import manually.
• Headless servers. Receiving is disabled when no players are connected.

Troubleshooting

• Invalid payload. - The other instance sent a packet the mod couldn't decode. Usually means a different, unrelated process is sending UDP to your port. Change the port.
• Could not send... - The OS rejected the send. Check that the destination port is valid and that no firewall rule is blocking localhost UDP.
• Cannot send ...: exceeds the N KiB limit. - The item is larger than the Max transfer size setting. Raise the limit (or set it to 0 for no cap) or send a smaller item.
• Rejected incoming transfer: exceeds the N KiB limit. - The other instance tried to send something larger than your Max transfer size. Same fix - raise the limit on the receiving side, or have the sender break the item up.
• ... is still being sent. - A previous send from this player hasn't finished yet. Wait for it to complete before sending another item.
• Version mismatch warning - The other instance is on a different Factorio version, or has a different version of this mod installed. Minor differences usually import fine; major version gaps may fail with Import failed.
• Import failed. - The payload arrived but couldn't be imported into the cursor. Usually a Factorio or mod version mismatch between sender and receiver.
• Blueprint is in preview. - The library blueprint hasn't finished syncing with the server. Wait for the sync and resend.
• Nothing happens on receive - Confirm the destination instance was launched with --enable-lua-udp=<port>. If a previous transfer stalled, wait a moment and try again.
• Two copies fighting over the same saves/mods/config - Both installs share the same user data directory. You may see Couldn't create lock file Factorio\.lock: 32 Is another instance already running? when starting the second copy. See the Factorio Wiki for per-platform write paths and how to make a copy portable.

License

MIT