MythxEngine

Add a condition to a combatant. Supports advantage/disadvantage and resistance/vulnerability effects.

Add a deadline/countdown to track. Specify either expiresIn (minutes from now) or expiresAt (specific time).

Record evidence discovered during investigation.

Record a player theory about the mystery.

Add an item to a character's inventory. Can add from a world pack template (worldPackId + templateId) or create a custom item. Requires itemized inventory mode.

Add a timestamped note to the session

Register a fabricated NPC on the session. Returns a stable `npcId` to use in `generate_portrait` and `showDialogue`. Use BEFORE introducing any NPC that isn't already in the world pack — without this the NPC has no identity and their portrait can't be tracked across turns.

Continue an NPC dialogue with the next line and response choices. Set endDialogue=true to end the conversation and return to narrative.

Advances time by N minutes

Move to the next player in turn order

Evaluate current scene for pacing issues. Helps identify when to cut or change direction. Based on the Alexandrian principle: 'Cut to the next meaningful choice.'

Add a condition to a character (narrative/exploration). For combat, use `add_combat_condition` instead so combat effects (advantage/disadvantage, modifiers) are picked up.

Apply damage directly to a combatant (bypassing attack roll)

Combine all generated content into a complete WorldContentPack and save it.

Link a player to a character

Perform an attack against a target. Supports advantage/disadvantage and damage type for resistance/vulnerability. Returns an envelope with `outcome` (five-tier) and a one-line `summary` as the headline; mechanical detail is in `result`, follow-up moves in `suggested_next`.

After seeding, returns ALL generation prompts at once for parallel LLM execution. Execute each prompt with an LLM, then call save_generation_result for each result. This replaces calling individual generate_* tools one by one.

Look up multiple entities at once. More efficient than individual lookups. Returns summaries for each entity.

Open a shop interface for the player. Loads items from world pack NPC/location data. Sets the stage to 'shop' so the player can browse, buy, and sell items.

Purchase an item from a shop. Deducts gold from the character and adds the item to their inventory.

Check if any time-based clock stages have triggered based on current game time.

Create a new character in the session

Add a player (human or AI) to the session

Create a revelation that can be discovered through multiple sources. The ultimate flexible clue.

Create a new game session, optionally associated with a world pack.

Deal damage to a character (narrative/environmental, not from combat resolution). Floors HP at 0 and reports defeat. For combat attacks, use `attack`. For combat-target damage, use `apply_damage`.

Delete a character from the session

Remove a player from the session

Delete a session and all its data

Delete a saved world pack.

End the current combat

End turn-based coordination and return to free-form play

Equip an item from inventory to an equipment slot. Automatically unequips existing item if slot is occupied (unless disabled).

Expand an archetype with additional detail (skill progression, party role, RP hooks). Returns a prompt for LLM execution.

Expand a location with additional detail (areas, random encounters, treasure). Returns a prompt for LLM execution.

Expand a monster with additional detail (lair, variants, ecology). Returns a prompt for LLM execution.

Expand an NPC with additional detail (backstory, combat stats, quest hooks). Returns a prompt for LLM execution.

Export a world pack to JSON and/or markdown format.

Execute a flashback to establish retroactive preparation. Costs 2 stress (default; world-overridable).

Generate an opening description for a new scene. Uses location data and tone to create engaging scene framing.

Generate appendices (items, conditions, encounters) for a world pack.

Generate playable character archetypes based on the world seed. Returns a prompt for LLM execution.

Generate story arcs that group situations around central tensions. Returns a prompt for LLM execution.

Generate status effects and conditions based on the world seed. Returns a prompt for LLM execution.

Create an encounter matching the specified parameters. Uses available monsters from the world pack.

Generate encounters based on the world seed. Returns a prompt for LLM execution.

Generate personalized engagement hooks for a situation, location, or theme.

Generate factions with relationships, resources, and territory based on the world seed. Returns a prompt for LLM execution.

Generate items based on the world seed. Returns a prompt for LLM execution.

Generate locations based on the world seed. Returns a prompt for LLM execution.