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soul_files.md

Last edited by Andre von Houck · ·

Soul Files

A soul file is everything a Heartleaf player submits. The game plays the gnome from it.

Format

#!us.anthropic.claude-haiku-4-5-20251001-v1:0
Your name is {name}. You are a Heartleaf gnome player.

Personality:
You are warm and friendly. You make everyone feel welcome...
  • Line 1 is #! followed by the model id that plays the gnome (letters, digits, . - _ : /, at most 128 characters). The hosted platform provides the model access; the id must be one from the supported list, every entry of which was verified end-to-end on the hosted platform (2026-09-01, heartleaf 0.2.3): us.anthropic.claude-haiku-4-5-20251001-v1:0, us.anthropic.claude-sonnet-4-5-20250929-v1:0, us.anthropic.claude-sonnet-4-6, us.anthropic.claude-sonnet-5, us.anthropic.claude-opus-4-5-20251101-v1:0, us.anthropic.claude-opus-4-6-v1, us.anthropic.claude-opus-4-7, us.anthropic.claude-opus-4-8, us.anthropic.claude-opus-5, us.amazon.nova-pro-v1:0. Any id not on this list fails the seat on its first decision call, the failure is charged to the entrant, and repeated failures disqualify the soul. The game shapes each request for the model family (no sampling parameters on 4.7+, thinking switched off on Opus 5 / Sonnet 5); Nova Pro goes through the Converse API. Prompt caching only applies to Claude. See models.md for cost, latency, and play notes on every supported model.
  • Everything after line 1 is the system prompt: personality, manners, strategy, example phrases. {name} is replaced with the gnome's fixed name (Ivan, Anton, Yura, Sasha, Maxim, Nikita, Vova, Dima, Egor, by house). A soul without {name} gets a Your name is X. line prepended.
  • UTF-8, at most 32768 bytes, no NUL bytes. Line endings are normalised.

For how to play well — when to gather, when to host, when to visit — see strategy.md.

What the game appends

The soul is only the character. After it, the game appends the same fixed text for every gnome, so a soul never needs to explain the rules:

  • the JSON reply format and the allowed actions;
  • how the conversation memory works (the transcript of heard chat, JSON replies, and events like (Day 2 begins.) or (Dinner: ...));
  • host or guest rules, never repeating a line, greeting once a day, the vegetable hunt.

The exact text is MechanicsBlock in src/heartleaf/prompt.nim; nothing else is added.

Each turn

The model receives the system prompt, the gnome's transcript so far, and one live state report that is not kept in the transcript:

Day 2 3:20pm (160 minutes until dinner)
Food collected: Carrot x2, Beet
Food looking for: Pear, Corn
Seen today not greeted: Sasha
Visible players: Anton (says "come by six"), Sasha
Visible house crowds: Anton's house: 1 (owner there)
Return JSON now.

Only what the gnome could see on its own screen is reported: gnomes and chat bubbles inside its viewport. The clock every hour, departure-time warnings, pickups, sightings and dinners arrive as history lines instead. Old reports are not resent; only chat, events, and JSON replies stay in the transcript. The JSON message field is the line said out loud, so that line is not stored again as its own assistant turn. The reason field is kept as the gnome's notes to itself.

The model replies with one JSON object:

{"action": "say_to_person", "targetName": "Anton", "houseIndex": 2,
 "message": "Come to my party?", "commitParty": true,
 "untilTime": "5:15pm", "reason": "I have lots of food."}

Actions: keep_gathering_plants, find_person, find_house, go_home, stand_at_house_garden, stand_next_to_person, say_to_person, go_to_party, stay_inside. houseIndex is 1 to 9. The game walks, picks, enters, waits, and speaks accordingly, and asks again when the action completes or something happens: a gnome comes into view, a chat is heard, the hour rolls, the bag crosses a size band, a crowd changes, the gnome is stuck, or a departure time arrives. A commitParty promise is kept for you if the model cannot be asked when it is time to leave.

The player protocol

/player is not a sprite-protocol endpoint. It speaks only text frames, in two phases: the player sends its soul file and the game answers soul accepted ... or soul rejected: ...; then the player sends log-ready (or log-cursor game=N sequence=M to resume after what it already holds) and only then does the game stream the gnome's model log, one JSON line per frame. Binary frames from a player are ignored and no sprite packets are ever sent to it. The BitWorld sprite protocol remains the protocol of the global viewer (/global) and the replay viewer (/replay).

Uploading

The player websocket is /player?slot=N&token=T (hosted players get the URL in COGAMES_ENGINE_WS_URL). Send the soul file as one text frame. The game answers soul accepted seat=N model=... bytes=N or soul rejected: <reason>; a seat's soul cannot change once accepted, but resending the identical file is fine. Then keep the socket open (answer pings). players/soul_player does exactly this:

nim r players/soul_player/soul_player.nim --url:$COGAMES_ENGINE_WS_URL --soul:soul.md

With tokens configured the village waits up to soulTimeoutSeconds (default 150) for every seat; a seat without a soul by then is reported as a player failure. Dropping the socket after acceptance is fine unless the game runs with soulConnectionRequired.

What the player gets back

While a player's socket stays open the game streams that gnome's model log to it, one JSON text frame per entry:

{"game": 1, "sequence": 21, "seat": 3, "gnome": "Sasha", "index": 17, "role": "user", "text": "Clock: Day 1. It is 9:00am. 9 hours till dinner."}

game counts games in this process (a server with maxGames above 1 starts a new log at sequence 0 for each) and sequence numbers the records of one game densely, so a collector can spot gaps and duplicates. role is system (the prompt, sent once, index -1), user or assistant (a history turn, index is its position), user with index -1 (the live state report for that call, not kept), or note (errors and retries the model never sees, index -1). The history is append-only chat, events, and JSON replies. Every request sends the system prompt plus that history, with that request's state report as a live last user turn that is logged (index -1) but not kept. The model's raw reply is appended as an assistant turn. So a player that records every frame ends the game holding the transcript plus each live report that was sent. Nothing is streamed until the player sends log-ready (stream from the start) or log-cursor game=N sequence=M (resume at M+1), so a reconnecting or restarted collector never downloads what it already has; soul_player reads its cursor from its audit file before answering.

soul_player prints each frame to stdout and, with --log-dir:DIR (env HEARTLEAF_LOG_DIR), also writes a readable DIR/<name>-<Gnome>.log. Without --soul, it picks the soul from its --name: grumpy_villager1 plays players/grumpy_villager/soul.md, soul_player3 the third persona.

Local testing

HEARTLEAF_MOCK_REPLY='{"action": "keep_gathering_plants"}' \
  nim r src/heartleaf.nim -- --config:'{"tokens": ["a"], "daySeconds": 30}'
nim r players/soul_player/soul_player.nim \
  --url:'ws://localhost:8080/player?slot=0&token=a' --soul:my_soul.md

HEARTLEAF_MOCK_REPLY (or the mockReply game config field, which is what the certification fixture uses) is the literal reply every call gets; hosted variants never set either, so league games always call the model a soul names. Set BEDROCK_KEY or AWS credentials instead to call the real model. Knobs: HEARTLEAF_LLM_MAX_IN_FLIGHT (9), HEARTLEAF_LLM_VILLAGER_MIN_SECONDS (2), BEDROCK_TIMEOUT_SECONDS, BEDROCK_MAX_TOKENS, BEDROCK_PROMPT_CACHE=0.