interactive-story/planning/archive/phase0/PHASE-0B-AI-DND-EXPERIMENT.md

Phase 0B — Experiment A: AI-DnD

All results are from a live server on 127.0.0.1:8321 with a fresh SQLite database, generating against local Ollama.

A1. Runs with Ollama locally — yes

Default endpoint_url is http://localhost:11434/v1. After setting only the model name:

POST /api/settings/test → {"ok":true,"models":["qwen2.5:0.5b"]}

Three streamed turns produced 101/162/113 SSE events with player, chunk and done types and a coherent transcript.

A2. RPG state can be left empty — yes

schemas.AdventureCreate.scenario_id is optional. With it null, crud.create_adventure sets world_state={} and creates no story cards, no scripts and no opening action, but still calls tree.head_branch(...) so the story tree exists from the start. A noir campaign created this way played, branched, summarized and retrieved memories normally. The RPG referee is opt-in per scenario, not a core dependency.

A3. Retry is non-destructive; Undo is destructive

Measured on the same adventure, reading rows straight from SQLite:

baseline rows: 6  ids [1,2,3,4,5,6]

RETRY  → new action id 7; rows 7 ids [1..7]
         /variants at the tip lists BOTH take 0 (id 6) and take 1 (id 7)

UNDO   → rows 7 → 4;  DELETED ids = [5, 6, 7]

Undo removed the player action (5), the live AI take (6) and the alternate take that the retry had just preserved (7). nodes.delete_turn deletes every attempt in the group on that branch and calls memorybank.forget_node. There is no redo endpoint anywhere in routers/.

This contradicts reports/PRELIMINARY-RECOMMENDATION.md, which credits AI-DnD with "non-destructive retry" (true) and generalizes it to rollback (false).

A4. Branching is non-destructive

Adding an alternate take at a passed turn (POST /actions/3/takes) forked automatically:

before: ids 1-8, all branch 1, depths 0-7
after : ids 1-8 unchanged on branch 1
        id 9  branch 2 depth 2   (the alternate player action)
        id 10 branch 2 depth 3   (its AI continuation)

/branches → [ {id:1, parent:null,  fork_depth:null, own_actions:8},
              {id:2, parent:1,     fork_depth:1,    own_actions:2, is_head:true} ]

Not one row of branch 1 was touched. Note the semantics: after_id pointing at a node that is live and on the path is a no-op, not a fork. A fork happens only when writing below a take the story has moved past (nodes.stand_on). So "restore to an arbitrary earlier turn and branch" is not directly expressible today — it must go through creating a take at that turn.

A5. Memory isolation across branches — correct, with negative control

Memory bank enabled, summary model qwen2.5:0.5b, embeddings nomic-embed-text, memory_top_k=5. Three more turns played on branch 1 establishing possessions (brass key, silver revolver, bullets).

memories stored:  (id 1, branch 1, depth 5)
                  (id 2, branch 1, depth 11)

on branch 2 (forked at depth 1):
  memories retrieved = {"used": [], "error": null}
  leak probes over the FULL assembled prompt:
    'brass key' False | 'revolver' False | 'lockbox' False
    'ashtray'   False | 'bullets'  False

NEGATIVE CONTROL — switch back to branch 1:
  memories retrieved = 2, top similarity 0.8087
  'revolver' present in prompt = True

The empty result on branch 2 is genuine isolation, not a dead retrieval path. memorybank.retrieve_memories applies lineage.path_of(db, adventure).clause(models.Memory), and Memory rows carry branch_id plus source depths. Eviction deliberately ignores the branch clause, which is correct — it is a capacity concern.

History is likewise lineage-scoped: branch 2's prompt contained only its own text.

A6. Insights / prompt transparency — already sufficient

GET /adventures/{id}/context returns the exact next prompt broken into labeled sections with token costs:

narrator 57 | ai_instructions 9 | persona 15 | plot_essentials 24
history 988 | used_memories 143 | length_hint 46

Per-action snapshots are stored on Action.context_snapshot and served by GET /actions/{id}/context. This satisfies specification §11 as-is.

A7. Scripting/QuickJS can be removed cheaply

quickjs is imported in exactly one file (scripting/engine.py). The whole feature is reachable through two symbols (run_hook, ScriptPipeline) across four call sites plus routers/scripts.py.

Disposable experiment: made quickjs unimportable via a meta_path blocker and replaced run_hook with a pass-through stub.

app.main imports OK with scripting stubbed and quickjs absent
19 failed, 613 passed  (3.0% of the suite)

Every failure is in test_turn_flow_integration, test_take_state, test_story_tree_baseline or test_retry_variants, and every one fails for the same reason: those tests use a JS output_js hook as the instrument to make state observable, e.g. test_play_then_undo_reverts_gold seeds a GOLD_SCRIPT and asserts script_state == {"gold": 10} then {} after undo. The behavior under test (per-node state rollback) is intact; only the measuring device is gone. Re-instrumenting against world_state_after, which is already snapshotted per node, is the fix.

A8. Hosted/cloud features

MULTI_USER is off by default and gates ten modules (auth, limits, netguard, cleanup, security, analytics, routers/{auth,analytics,debug,story_cards}). analytics.py is a self-hosted counter writing to two local tables — no third-party tracker and no outbound call — so it is removable rather than dangerous. render.yaml, the demo-key path and psycopg are the hosted leftovers.

netguard.py is worth flagging: it refuses endpoints that resolve to non-public addresses, and only in multi-user mode. That is SSRF protection for a hosted deployment. Our requirement is the opposite — warn on endpoints that are not loopback. See ai-adventure's _endpoint_warnings for the shape we want.