chat/CLAUDE.md

Roleplay Engine

Local-first roleplay chat app that treats fiction as a simulation, not a chat log. The LLM is a renderer for structured world state — it does not hold state.

See rp-engine-design.md for the full design. This file is the working summary.

Why this exists

Fixes three failure modes of conventional RP chatbots:

1. Memory loss — old context drops as history grows
2. Quality decay — bots get terse and generic over long conversations
3. Stale state pollution — bots fixate on past props (the "picnic basket" problem)

Hard scope constraints

• Single user, single machine (the user's Mac)
• Max 3 entities per scene: you + up to 2 bots (botA, botB)
• Chat-only — no voice, no real-time

The 3-entity cap is load-bearing: it makes the relationship graph fully enumerable (6 directed edges + 1 group node). Don't design for N entities.

Architecture

• Mac (always-on): web UI, orchestrator, persistence, event queue, retrieval, prompt construction, all state.
• Inference endpoint: stateless generate(prompt, params) -> text. Swap implementations (cloud API, rented GPU, local MLX/llama.cpp) behind one interface. The orchestrator never knows which.
• Streaming required for UX.

Core concepts (vocabulary)

• Entity: you | botA | botB. Has identity (immutable), state (mood/goals/status), activity, per-POV memory.
• Container: anything with slots that holds entities (car, booth, room). Has properties (moving, public, audible range). Spatial grounding lives here, separate from the relationship graph.
• Activity record: per-entity live struct — position (container+slot), posture, current action (verb, duration, interruptible, required_attention), holding, attention, status. Always in the prompt as a small structured block.
• Relationship graph: 6 directed edges (asymmetric feelings matter — never collapse to a single shared field) + 1 group node. Edges hold affinity, trust, summary, knowledge-known-about-target, private moments, last-interaction.
• Scene configurations: exactly 4 — solo with botA, solo with botB, all three present, botA+botB without you ("meanwhile…"). Each has a fixed prompt-loading rule.
• Witnessed-by flag: every memory has a 3-bit [you, botA, botB] mask. A speaker only sees memories where their bit is set. This is the mechanism that prevents bots referencing things they can't know.
• Event: scoped lifecycle (planned | active | completed | cancelled | expired) with its own props, preconditions, on_start/on_complete hooks, significance. Solves the picnic-basket problem — props live and die with the event, only narrative gist promotes to memory.
• Active threads: unresolved plot tensions. Sticky in context until resolved/dropped. Cheap, anchor continuity across compressed scenes.
• Scene: closes when container changes meaningfully or significant time passes. Compression boundary.
• Per-POV summary: every witness gets their own record of a closed scene, written from their POV. Different details, different interpretations. This is what gives bots inner lives — never write omniscient narration into per-POV stores.
• Time skip: elision (skip the boring middle of an in-progress activity) vs jump (next morning, a week later). Skips run intervening events forward, compress, reset landing activity.

What promotes out of an event (and what doesn't)

• Object acquired → inventory
• Knowledge gained → edge knowledge field
• Relationship change → edge summary
• Everything else stays in the closed event record. The blanket, the basket, the specific sandwich do not become memories. This rule is the whole point — don't bypass it.

Persistence

• SQLite (single file) for everything structured. WAL mode, foreign keys on, each turn in a transaction.
• sqlite-vss or sqlite-vec for embeddings (same DB file). Decide at Phase 4.
• JSON for snapshots, character templates, scene exports.
• No Postgres, Redis, Pinecone, Docker. Single-user; don't over-engineer.

Schema is event-sourced. See design doc § "Persistence Layer" for the full sketch.

Event sourcing — non-negotiable

State is a projection of an append-only event log. State is never mutated directly — append an event, the projector applies it.

Event kinds: user_turn, assistant_turn, time_skip, event_triggered, edge_update, scene_transition, entity_state_change, activity_change.

This buys: free rewind, trivial replay-debugging, schema migrations against the same log, branching ("what if BotA had said yes").

Determinism on replay: LLM calls are nondeterministic. Store the outcome in the event payload — on replay, use the stored outcome. Never re-call the LLM during replay.

Snapshots every N events / M minutes so we don't replay everything on load. Log is source of truth.

Prompt construction

A speaker's prompt is assembled from their edges and their witnessed memories — never the global state. BotA and BotB are effectively two separate agents who happen to share a scene.

Order (for speaker BotA, with you and BotB present):

1. BotA identity + current state
2. BotA → You edge
3. BotA → BotB edge
4. Group node (only if all three present)
5. World state (time, weather, location)
6. Active scene description
7. Activity snapshot for all present entities
8. Active threads
9. Recent dialogue window
10. Retrieved memories (top-K, witness-filtered, BotA-owned)
11. Currently active events + their props

After every utterance, run a state-update pass on every present entity, not just the speaker. Silent witnesses still update edges.

Memory retrieval

• Always-loaded: pinned, current scene, active threads, recent N scenes (no retrieval).
• Retrieved: top-K vector search over the speaker's memory store, filtered by witness flag, with recency + significance boosts.
• Keep K small. Bloated retrieval poisons the prompt.
• Phase 1: SQLite FTS5 is enough. Vector search comes at Phase 4.

Implementation phases

1. Core loop: schema, entities + edges, single container, event log + projector, single-bot conversation, one LLM backend, streaming UI, manual rollback.
2. Multi-entity: second bot, group node, scene configs, witness filtering, per-POV memories, activity/containers, scene transitions with compression.
3. Events & skips: event queue with triggers, time skips, active threads, significance classifier.
4. Polish: vector retrieval, branching, surgical delete + regenerate, snapshots, backups, impact-preview UI for rewinds.

Don't jump phases. Phase 1 must work end-to-end before Phase 2 lands.

Conventions for working in this repo

• Don't bypass the event log. Any state change goes through an event. If you're tempted to UPDATE a row directly, you're doing it wrong.
• Don't collapse directed edges. botA → botB and botB → botA are independent. Asymmetry is the point.
• Don't promote event props to memory. Only the four promotion categories above survive an event closing.
• Per-POV, not omniscient. When writing scene summaries, write one per witness, from their angle.
• Witness filter every memory read. A bot must never see a memory their bit isn't set on.
• Activity block is always in the prompt. It's the spatial anchor that prevents "leaning on the kitchen counter while in a car" failures.
• Streaming on the inference path; non-blocking bookkeeping (significance classification, embeddings, snapshots) runs while the LLM streams.
• No Docker, no extra services. SQLite + a process. Push back on suggestions to add infrastructure.

Open decisions (deferred — don't pre-decide)

• Token budget strategy (during Phase 1, with real prompts)
• Embedding model (Phase 4)
• sqlite-vss vs sqlite-vec (Phase 4)
• UI framework (local web app / Tauri / Electron / native — TBD)
• Inference hosting (start with a cloud API, re-evaluate later)
• Character template format (during Phase 1)
• Multi-session / multi-character casts: out of scope for v1. Leave cheap schema hooks only.