CAPIE¶

CAPIE (Cyprian's API Extender) is a small native library for Hearts of Iron IV. It gives mods a few abilities that the game's script language does not have, such as free text names for countries and reading what the player typed into a text field.

What CAPIE is¶

CAPIE is two Windows DLLs that run inside the game process while you play. It does not change any file of the game. It hooks a few places in the running hoi4.exe, supplies text when the game looks it up, and adds data to game commands that the player issues. Mods talk to it through ordinary HOI4 script.

Rename Anything is the first mod built on CAPIE. It lets you rename your country, its leader and its parties in the panel where the name is shown, and your subjects through diplomacy. Your country's name and adjective need CAPIE, because the game has no script effect that takes free text for a country. The in-panel text fields need it too: a script cannot read what the player typed, so CAPIE passes the text to the mod inside a game command.

What CAPIE is not¶

• It is not a game patch. It never writes to the game folder, hoi4.exe or steam_api64.dll.
• It is not a network client. Current builds import only KERNEL32 and bcrypt.
• It is not a general scripting engine or a way to run arbitrary code from a mod. Mods can use only the operations CAPIE defines, and CAPIE checks every input.
• It is not anti-cheat and not a multiplayer server. In multiplayer it can only refuse to switch its own features on (see Multiplayer).
• It does not change cosmetic tags. A custom country name and a chosen flag are layers of their own, so renaming keeps the flag and choosing a flag keeps the name (see Name layers).
• It is not needed for names a mod knows in advance. Vanilla set_cosmetic_tag, set_party_name and set_character_name already handle those.

Where to go next¶