All or nothing by Mnehmos · Pull Request #110 · Mnehmos/mnehmos.rpg.mcp

Mnehmos · 2026-09-27T17:12:11Z

A turn either happens or it doesn't. Closes #108 and fixes the open review findings from #95.

The problem (#108)

A tool call can make several database writes, and each one saved on its own. If a call failed halfway, the first writes stayed saved and the rest never happened. Example: a rogue drinks a potion, then Dashes into a wall. The potion is gone and the healing counted, but she never moved and the turn never advanced.

What changed

1. Every tool call is all-or-nothing (`src/storage/unit-of-work.ts`)

Each MCP tool call runs in one SQLite transaction. If the call throws, returns isError, or has an error field in its payload, all of its writes roll back.
Calls on the same campaign database run one at a time. Otherwise a call that is awaiting something would have its transaction open, and a second call's writes would join that transaction and roll back with it. Different campaigns still run in parallel. The audit-log write stays inside the lock.
In-memory state follows the rollback. CombatManager snapshots an engine the first time a call touches it and restores that snapshot if the call rolls back. Engines created during the call are removed, and deleted ones come back. WorldManager drops worlds created during a rolled-back call.
No events for a rolled-back call. Pubsub delivery (to the durable inbox and live subscribers) waits until COMMIT.
Error responses now carry isError: true. That covers formatMcpError, validation errors, and any tool response whose payload says error.

2. `batch_manage` / `execute_sequence`

Every step reported success. The parser looked for a  marker that nothing emits. On top of that, router errors had no isError, so failed steps showed ✅ and stopOnError never fired. It now reads the real embedded JSON.
{{step.field}} chaining works. It used to always resolve to undefined. An unresolved reference now fails its step instead of passing undefined to the next tool.
Each step runs in a savepoint. With stopOnError (the default), any failure rolls back the whole sequence, and the response says so (rolledBack: true, isError). With stopOnError: false, successful steps stand and failed steps leave nothing behind.
create_characters runs each character in its own savepoint, so a failed create can't leave half a character.

3. One writer per table

Each of these tables was written from more than one file:

Table	Change
`items`	Corpse harvest now goes through `ItemRepository`. The old INSERT skipped `properties` (same drift as #81). The harvest also runs as one transaction.
`characters`	Currency writes (from `InventoryRepository`) and `character_manage delete` now go through `CharacterRepository`.
`worlds`	Tile-cache SQL moved from `tools.ts` into `WorldRepository`.
`event_logs`	New `EventLogRepository` replaces two hand-written INSERTs.

4. #95 review findings

Events dropped on local transports: fixed. stdio, TCP, unix and WebSocket never set a tenant, so the bridge dropped every event and poll_events was always empty. Single-user mode now writes to the local database. HTTP still drops events that have no tenant.
Claim race in pollAndConsume: fixed. It is now one IMMEDIATE transaction, the update is guarded on consumed_at IS NULL, and it only returns rows it actually claimed.
No producer ID: fixed for combat. Engines stamp encounterId on everything they publish, so inbox rows get a sourceId.

⚠️ Contract changes for `rpg-mcp-live`

More responses now carry isError: true: anything whose payload reports error. This is standard MCP behavior, but check that reference-engine-client.ts doesn't treat isError as a transport failure.
A call that reports an error now saves nothing. Before, it could save part of its work.
A failing execute_sequence with the default stopOnError now applies nothing and returns isError.
pollAndConsume returns events with consumedAt set.

Known trade-offs

combat_manage next_turn runs the auto-on-turn agent's LLM call inside the handler, so that campaign's lock is held for the length of the call. Other calls on the same campaign wait; other campaigns don't. Moving the agent call out of the transaction is a good follow-up.
success: false alone does not trigger a rollback, because some tools use it for an outcome, like a failed skill check. It does count as a failed step inside execute_sequence.
distribute_items is still best-effort for each item.

Tests

New: tests/storage/unit-of-work.test.ts (12) and tests/server/all-or-nothing.test.ts (12). They cover the drink-then-Dash tear, rollback on isError, serialization, savepoints, deferred events, combat snapshot restore, batch rollback and chaining, the inbox claim, single-user events, and the harvested item's properties.
Full suite: 2299 passed, 7 skipped. The 3 websocket.test.ts failures also fail on main in this environment (EAFNOSUPPORT, no IPv6).
Smoke-tested the built server over stdio with the MCP SDK client:
- Error responses carry isError.
- A failing sequence leaves 0 characters.
- poll_events returns combat events with their encounter ID, and a second poll returns nothing.

🤖 Generated with Claude Code

https://claude.ai/code/session_012FntDZ4y2gh1q6mw69yAoo

Generated by Claude Code

Summary by CodeRabbit

New Features
- Multi-step operations now roll back cleanly when they fail, with optional continuation after individual step failures.
- Combat events include encounter information, and event notifications are delivered after successful changes are committed.
- Event polling and resource harvesting now handle updates more consistently.
Bug Fixes
- Failed character creation and other operations are less likely to leave partial changes behind.
- Single-user databases can process events without tenant context.
Tests
- Added coverage for rollback behavior, batch operations, event handling, and related error responses.

Each MCP tool call now runs in one SQLite transaction that commits or rolls back as a unit. Covers the issue #108 drink-then-Dash case. - Per-connection lock so an awaiting call's open transaction can't absorb another call's writes. The audit write stays inside the lock. - Rolls back on a throw, isError, or an error field in the payload. Those responses now carry isError: true. - CombatManager and WorldManager snapshot in-memory state and restore it on rollback. - Pubsub delivery waits for COMMIT; rolled-back calls announce nothing. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012FntDZ4y2gh1q6mw69yAoo

- The step parser looked for a  marker nothing emits, so every step showed success, stopOnError never fired, and {{step.field}} references resolved to undefined. It now reads the real embedded JSON. - An unresolved reference fails its step instead of passing undefined on. - Each step runs in a savepoint. With stopOnError (the default) any failure rolls back the whole sequence and returns isError. With stopOnError=false, successful steps stand and failed ones leave nothing. - create_characters runs each character in its own savepoint. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012FntDZ4y2gh1q6mw69yAoo

- items: corpse harvesting goes through ItemRepository, so properties is written (same drift as #81). Harvest is now one transaction. - characters: currency writes and 8000 delete go through CharacterRepository. - worlds: tile-cache SQL moved into WorldRepository. - event_logs: new EventLogRepository replaces two hand-written INSERTs. - event_inbox: pollAndConsume is one IMMEDIATE transaction and only returns rows it actually claimed (#95 review). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012FntDZ4y2gh1q6mw69yAoo

- stdio, TCP, unix and WebSocket carry no tenant, so the #95 bridge dropped every event and poll_events was always empty. Single-user mode now writes to the local database. - Combat engines stamp encounterId on published events, so inbox entries record which encounter produced them (#95 review). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012FntDZ4y2gh1q6mw69yAoo

chatgpt-codex-connector · 2026-09-27T17:12:16Z

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Review configuration:

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Advanced

Run ID: dbd92ac9-3dce-499f-8e3a-181a3350a328

📥 Commits

Reviewing files that changed from the base of the PR and between c178d73 and 97b46db.

📒 Files selected for processing (8)

src/engine/combat/engine.ts
src/engine/combat/rng.ts
src/engine/pubsub.ts
src/server/events.ts
src/server/state/combat-manager.ts
src/server/state/world-manager.ts
tests/server/all-or-nothing.test.ts
tests/storage/unit-of-work.test.ts

📝 Walkthrough

Walkthrough

Tool handlers now run in serialized transactional units of work. Batch sequences use savepoints, and rollback hooks restore selected in-memory state. Several persistence operations now use repository methods, and event delivery and polling use transaction-aware handling.

Changes

Transactional tool execution

Layer / File(s)	Summary
Transaction and error-response contract `src/storage/unit-of-work.ts`, `src/utils/tool-response.ts`, `src/utils/action-router.ts`, `src/server/types.ts`, `CLAUDE.md`, `tests/storage/unit-of-work.test.ts`, `tests/server/all-or-nothing.test.ts`	Added atomic and serialized execution, savepoints, rollback hooks, deferred effects, and response error detection. Added tests for transaction outcomes, serialization, savepoints, and error responses.
Handler and batch transaction flow `src/server/index.ts`, `src/server/consolidated/batch-manage.ts`, `tests/server/all-or-nothing.test.ts`	Registered handlers now run through serialized and atomic wrappers. Batch sequences resolve nested references, isolate steps with savepoints, and report rollback status and applied changes.
Rollback-aware state and event delivery `src/server/state/`, `src/engine/combat/`, `src/server/handlers/combat-handlers.ts`, `tests/storage/unit-of-work.test.ts`	Combat and world managers register rollback callbacks. Combat events include encounter IDs, and PubSub notifications are deferred until commit.
Repository-backed persistence changes `src/storage/repos/character.repo.ts`, `src/storage/repos/inventory.repo.ts`, `src/storage/repos/corpse.repo.ts`, `src/storage/repos/event-log.repo.ts`, `src/storage/repos/world.repo.ts`, `src/server/consolidated/character-manage.ts`, `src/server/consolidated/math-manage.ts`, `src/server/consolidated/perception-manage.ts`, `src/server/tools.ts`, `tests/server/all-or-nothing.test.ts`	Currency, event-log, corpse-harvest, and tile-cache operations now use repository methods. Corpse updates, item creation, and inventory transfer run in one transaction.
Event inbox polling and tenant handling `src/server/events.ts`, `src/storage/index.ts`, `src/storage/repos/event-inbox.repo.ts`, `tests/server/all-or-nothing.test.ts`	Event polling claims rows in an immediate transaction and uses serialized atomic handling. The event bridge persists events without tenant context when single-user database mode is active.

Priority: ➖ Normal

Estimated code review effort: 4 (Complex) | ~60 minutes

Change: Bug fix · Severity of issue fixed: Medium

Sequence Diagram(s)

sequenceDiagram
  participant ToolClient
  participant serializedHandler
  participant atomicHandler
  participant ToolHandler
  participant SQLite
  participant RollbackHooks
  participant afterCommit
  ToolClient->>serializedHandler: invoke registered handler
  serializedHandler->>atomicHandler: run under database serialization
  atomicHandler->>SQLite: BEGIN IMMEDIATE
  atomicHandler->>ToolHandler: execute handler
  ToolHandler->>SQLite: read and write data
  ToolHandler-->>atomicHandler: return result
  alt result is an error
    atomicHandler->>SQLite: ROLLBACK
    atomicHandler->>RollbackHooks: restore in-memory state
  else result succeeds
    atomicHandler->>SQLite: COMMIT
    atomicHandler->>afterCommit: run deferred effects
  end

Merge Risk: 🟡 Moderate · up to c178d

This change makes each tool call all-or-nothing, but three gaps remain. A failed combat action that is rolled back can still change later dice rolls. Rollback can miss in-memory changes when two combat managers track the same encounter. If saving an event to the inbox fails, its game change stays committed while poll_events never returns the event. These gaps should be fixed before merging.

Security Architecture Review

Security architecture risk: 🟡 Moderate · up to c178d

Per-campaign serialization and rollback strengthen tool execution, but a committed action can still lose its durable event notification. Some interruption and recovery behavior remains unverified.

Retained concerns

Medium · reliability · inferred: Event-inbox persistence is deferred until after the action commits. If the process stops or the bridge write fails before persistence, a committed action has no durable event for downstream consumers to recover.

Security review details

Security Blast Radius

inferred — The new transaction and inbox failure mode is independently reachable per campaign database. Live notifications use a process-wide PubSub, but their missing recipient-tenant check was already present on main.

Trust Boundaries and Controls

observed — Durable event reads and consumption use the caller's selected database, while the bridge restores verified producer context for its write. The live subscription callback does not perform an equivalent producer-to-recipient comparison; that callback is unchanged by this PR.

Resilience and Maintainability Implications

inferred — For awaited, ordinary tool responses the transaction protects database writes and suppresses rollback events. It does not establish completion or cancellation of detached work, and a failed rollback hook can leave in-memory state unrestored.

Hardening Proposals

proposed — Persist an event or outbox record in the same campaign transaction as its state change, then deliver notifications after commit with recoverable retries.

🚥 Pre-merge checks | ✅ 3 | ❌ 2

❌ Failed checks (2 warnings)

Check name	Status	Explanation	Resolution
Linked Issues check	⚠️ Warning	Issue `#108` requires one durable outcome for a tool call and correct `batch_manage` failure handling. The PR adds `atomic()` and per-database serialization, rollback hooks for combat and world state, d…	Make the atomic boundary classify the applicable failure responses, including `success: false`, as rollback conditions. Ensure `distribute_items` either rolls back the complete call on an item failure or does not report a failed call after …
Docstring Coverage	⚠️ Warning	Docstring coverage is 55.74% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 61 functions across 25 files. (1 skipped:…	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title directly describes the main objective: making tool calls atomic so changes either commit together or roll back together.
Out of Scope Changes check	✅ Passed	The reviewed changes stay connected to issue `#108`. Event-inbox claim serialization, event metadata, repository routing, tile-cache access, currency persistence, and event-log consolidation support tra…

Full details: Linked Issues check

Explanation

Issue #108 requires one durable outcome for a tool call and correct batch_manage failure handling. The PR adds atomic() and per-database serialization, rollback hooks for combat and world state, deferred events, repository writers, savepoints, reference resolution, and tests. However, the default unit-of-work failure check does not treat success: false as a failure. distribute_items also remains best-effort per item. A call can therefore report failure while retaining earlier writes, which leaves the all-or-nothing requirement unmet.

Resolution

Make the atomic boundary classify the applicable failure responses, including success: false, as rollback conditions. Ensure distribute_items either rolls back the complete call on an item failure or does not report a failed call after retaining partial writes. Add regression tests for both cases.

Full details: Docstring Coverage

Explanation

Docstring coverage is 55.74% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 61 functions across 25 files. (1 skipped: 1 unsupported.)

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Inline comments:
Review comments at @src/server/events.ts:
- Line 76: Update the event bridge around persistBridgedEvent so inbox rows are
written within the producing transaction rather than in the after-commit
callback. Defer only live notifications, and preserve this behavior for both
single-user and tenant event paths.

Review comments at @src/server/state/combat-manager.ts:
- Line 18: Update the snapshot and rollback flow in combat-manager to capture
and restore the existing engine’s CombatRNG position alongside CombatState.
Reuse the relevant CombatEngine RNG state accessors so retries after rollback
use the same rolls.
- Line 26: Update the rollback key used by CombatManager’s onRollback
registration to include the manager instance’s identity, so guards for the same
combat ID in different instances register distinct rollback hooks.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Advanced

Run ID: 9cd40b0e-5816-413d-a033-ade899e65e3e

📥 Commits

Reviewing files that changed from the base of the PR and between 8b88726 and c178d73.

📒 Files selected for processing (26)

CLAUDE.md
src/engine/combat/engine.ts
src/engine/pubsub.ts
src/server/consolidated/batch-manage.ts
src/server/consolidated/character-manage.ts
src/server/consolidated/math-manage.ts
src/server/consolidated/perception-manage.ts
src/server/events.ts
src/server/handlers/combat-handlers.ts
src/server/index.ts
src/server/state/combat-manager.ts
src/server/state/world-manager.ts
src/server/tools.ts
src/server/types.ts
src/storage/index.ts
src/storage/repos/character.repo.ts
src/storage/repos/corpse.repo.ts
src/storage/repos/event-inbox.repo.ts
src/storage/repos/event-log.repo.ts
src/storage/repos/inventory.repo.ts
src/storage/repos/world.repo.ts
src/storage/unit-of-work.ts
src/utils/action-router.ts
src/utils/tool-response.ts
tests/server/all-or-nothing.test.ts
tests/storage/unit-of-work.test.ts

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…ager keys - The durable inbox subscribes as transactional, so its row is written inside the producing call's transaction and commits or rolls back with it. Live notifications still wait for COMMIT. - Combat snapshots include the RNG position, so a retried action gets the same rolls as the rolled-back one. - Rollback keys include the manager instance, so two managers guarding the same id don't overwrite each other's undo. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012FntDZ4y2gh1q6mw69yAoo

Inside a unit of work the inbox row is part of the change. A failed insert now propagates and rolls the producing call back, so a change can't commit without its event. Outside a unit there is no transaction to keep consistent, so the failure is still only logged. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012FntDZ4y2gh1q6mw69yAoo

claude added 4 commits September 27, 2026 10:11

coderabbitai Bot reviewed Sep 27, 2026

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Comment thread src/server/events.ts Resolved

Comment thread src/server/state/combat-manager.ts Resolved

Comment thread src/server/state/combat-manager.ts 8000 Resolved

claude added 2 commits September 27, 2026 10:20

Mnehmos merged commit a7c43cd into main Nov 2, 2026
4 checks passed

Mnehmos deleted the all-or-nothing branch November 2, 2026 16:34

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All or nothing - #110

All or nothing#110
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The problem (#108)

What changed

1. Every tool call is all-or-nothing (src/storage/unit-of-work.ts)

2. batch_manage / execute_sequence

3. One writer per table

4. #95 review findings

⚠️ Contract changes for rpg-mcp-live

Known trade-offs

Tests

Summary by CodeRabbit

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Security Architecture Review

❌ Failed checks (2 warnings)

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1. Every tool call is all-or-nothing (`src/storage/unit-of-work.ts`)

2. `batch_manage` / `execute_sequence`

⚠️ Contract changes for `rpg-mcp-live`