docs/modules/rust/PLAN.md

module-rust — the plan

Status: approved in outline 2026-09-15, not started. Five decisions of record settled; one question open (§3).

The dry run designed this module on paper and deliberately did not build it. This is the document that builds it. Where the two disagree, this one is later and wins — but the dry run's four findings still stand, and one of them (identity) has moved from a footnote to the critical path. §2 says why.

Nothing here is normative. MODULE_API.md is the contract, MODULE_SYSTEM.md the system, EVENTS.md the event design of record, and the Integration Kit is the teaching text this plan follows chapter by chapter. This document is a schedule and a set of decisions, not a specification.

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1. The shape, and what is already settled

Three new repositories, mirroring the three the platform already has for Ultima Online, plus the optional fourth part that lives inside the module:

Part	New repo	Mirrors	What it is
Website module	RunicGateway/Module-rust	Module-uo	Routes, schema fragment, prebuilt client chunk, nav
Sidecar	RunicGateway/rust-link	link	Owns the game connection and the durable copy
Oxide bridge plugin	RunicGateway/rust-plugins	servuo-plugins	C# inside the game, dials out, never blocks
(event capability)	—	—	Declarations inside Module-rust (kit ch. 5)

None exist yet. The module is built from integration-kit/template/, which CI holds against a pinned core — currently MODULE_API_VERSION 1.10.0.

Settled before this document and unchanged by it (dry run, org lead, 2026-08-19):

• One server, one sidecar, on that server's own host. A community with six servers runs six pairs; the module holds six clients and core never learns there is more than one.
• The plugin dials out. Rust's server is a binary, so the way in is Oxide's published hook API rather than source — and the shard-dials-out invariant survives that change of footing unchanged.
• No RCON. It was the original design and it was overruled.
• wipe_id on every table that holds gameplay data. It is the whole shape of the game in one column, and it is the first thing a UO-shaped mental model gets wrong.

2. Decisions of record

R1 — identity is an in-game link code for v1

Decided 2026-09-15 (org lead). A player proves account ownership by typing a command in-game; the plugin issues a one-time code; the website confirms it through the sidecar. Exactly the shape module-uo uses.

This is the dry run's finding 1 answered for now rather than closed. There is still no registerAuthProvider in the contract at 1.10.0 — verified against MODULE_API.md §2.4 on 2026-09-15 — so "Sign in with Steam", which every Rust community expects, is not reachable from a module today. The link code is one screen worse and needs no core change, so it is what v1 ships.

What changed since the dry run is the stakes, not the options. The dry run rated this survivable because the module only read: a site that renders a leaderboard does not need to know which account owns a Steam ID. R2 makes the site the author of who may do what in the game, and R3 makes it the thing that hands out loot. Both are grants against a Steam ID. A weak identity link is now a privilege-escalation path, not a missing convenience — so the code must be single-use, short-lived, rate-limited, and issued in-game to the player who will own it.

Adding registerAuthProvider properly stays the first candidate for a future MODULE_API bump. It participates in session creation, which is the one part of core a module must never be able to weaken, and it must inherit core's existing policy: SSO is link-only, identities are never auto-provisioned. Specified deliberately, not bolted on. It is out of scope here.

R2 — site-authored permissions are mirrored into Oxide's own permission store

Decided 2026-09-15 (org lead). The website is the author of record for groups and grants. The bridge plugin applies them through Oxide's own API (permission.GrantUserPermission / RevokeUserPermission), so Oxide is an enforcement cache and the site is the thing that remembers.

The alternative — the plugin keeping a private table only our own features consult — was rejected because it cannot reach any third-party plugin, and reaching them is the point: a grant authored on the site has to gate Kits.

Three properties fall out, and they are the reason this shape is worth its cost:

• Every third-party plugin honours site-authored grants with no adapter, because they all already call permission.UserHasPermission.
• A wipe stops being a data-loss event for permissions. The game forgets; the site does not, and re-pushes the whole set on the next connect.
• Hand edits are reported, not overwritten. Somebody typing oxide.grant at the console is drift, and drift is surfaced to an operator — the same posture a lease's restore() takes when it finds a value a human has moved (kit ch. 5).

This is a direction the Integration Kit has no chapter for, and that is a finding. Chapters 3 and 4 are the read path — data leaving the game. Chapter 5 is one-shot commands with a ledger and a teardown. This is neither: it is continuously reconciled state where the website is authoritative, and its nearest relative in the contract is the Team provider inverted — instead of core asking the module what the game knows, the module tells the game what the site knows. The mechanism it borrows is chapter 4's: every board's current state has exactly one producer, and it runs on connect, pointed the other way. Whether this deserves a sixth chapter is a question for phase 10, after it has been built once.

R3 — the Kits reward action registers always and refuses with a reason

Decided 2026-09-15 (org lead). Kits is required for event rewards, but "required" means the action always exists and fails honestly where it cannot work — { ok: false, retry: false, error: 'Kits plugin not installed' } — rather than vanishing from the authoring form or refusing to boot the module.

Two details from kit ch. 5 that this depends on and are easy to get wrong:

• The reason must be in error. Core reads exactly ok, retry and error off a failure envelope; a message under any other name is dropped and the operator sees a bare "<action id> refused".
• retry: false has to be reachable. Core's dispatcher enforces budgetMs and classifies a budget timeout as retry unconditionally — so if the sidecar client's timeout is longer than budgetMs, our own retry: false is unreachable code. Derive one constant from the other and assert the inequality in a test. The first module this project shipped had exactly that pairing.

R4 — Rust reaches an operator through the existing installer, behind --game

Decided 2026-09-15 (org lead). Not a second binary and not a shared-core refactor: the shipped installer grows a game dimension, --game servuo|rust, and keeps one release stream, one doctor, one update, one uninstall.

The shape of the work is set by where the coupling already is. The reusable half is already game-agnostic — src/service.rs and src/main.rs mention ServUO zero times, and net.rs, diff.rs, paths.rs and ui.rs barely more. The UO-specific half is concentrated in four files — install.rs, doctor.rs, overlay.rs, tier.rs — plus the bundle manifest, where OverlayComponent and ServUoCompat name the game in the schema itself.

So the change is: make the bundle's game payload a variant rather than an overlay, and ServUoCompat a per-game compat block. That is a schema change on the published bundles branch, and it is the part to design before touching code.

The Rust payload is much simpler than the UO one, which is what makes this affordable: no source tree to overlay, no patches/, no opt-in patch tier — a Rust install is a .cs file dropped into oxide/plugins/, plus the sidecar and its service, which the installer already knows how to do. What it gains instead is a prerequisite check: is Oxide installed, and is its build current enough. That is doctor's shape, not a new concept.

The protocol pairing check generalises unchanged. servuo-plugins/overlay.toml declares the protocol the overlay speaks and the installer refuses to pair a disagreeing sidecar; rust-plugins needs the same declaration under whatever name the variant gives it, and the refusal is the same refusal.

R5 — Teams come from Rust's first-party clans; the uMod Clans plugin is the richer tier

Decided 2026-09-15 (org lead). Basic functionality is built on Rust's own clan system; the third-party uMod Clans plugin is an optional layer for a much richer experience, and lands in phase 9 rather than phase 6.

The distinction matters more than the names suggest, so it is worth stating precisely:

• Rust's first-party clans are seven hooks in HOOKS.md — OnClanCreated, OnClanDisbanded, OnClanMemberAdded, OnClanMemberKicked, OnClanMemberLeft, plus colour and logo — each handing you a LocalClan. All seven are "no return behavior", which is exactly what a read-only bridge wants: there is nothing to abstain from, so kit ch. 4's return-null-from-every-veto rule has no work to do here. They need no plugin, and the rig is already running them (D:\rust\server\server1\clans.287.db).
• Rust's first-party Teams are a different system — twelve hooks, mostly vetoable — and are the transient in-game squad, not the persistent organisation. They are not what core's Team provider should be fed. Clans is the right choice and this is why.
• The uMod Clans plugin's API is not in our mirror. HOOKS.md is the game's 477 hooks; a plugin's own API is its own documentation. It is reached through [PluginReference] and is null when absent, making it an R3-shaped dependency that must refuse with a reason. It is also not currently staged locally and would need pulling and mirroring.

The one gap to design around: the seven first-party hooks carry created, disbanded, added, kicked and left — but no promote or leader-changed event. Core's provider requires getTeamLeaders, so leadership is read off LocalClan at snapshot time rather than tracked from transitions. That makes phase 6 partly snapshot-driven where the dry run predicted it would be fully event-driven — a small correction to that document, recorded here rather than silently.

3. Open question

Which other uMod plugins are in the required base set? Kits is named. The rest of "a couple" is not, and phase 0 cannot finish its install list without it. Everything beyond the base set is phase 9's optional tier.

D:\rust\oxide\plugins\ is currently empty, so whatever the set is, all of it is a fresh install.

4. The test rig

D:\rust on the org lead's workstation. It has been booted, it has a generated world (procedural, seed 1234, size 4000, save v287) and Oxide 2.0.7585 matched to its build, and its Oxide permission store already holds a default and an admin group with one admin user — which means R2's mechanism can be exercised on day one.

Two traps recorded here because both cost time before they were understood:

• D:\rust\start.bat updated the wrong directory — fixed 2026-09-15. It ran steamcmd +force_install_dir c:\rustserver\ +app_update 258550 and then launched D:\rust\RustDedicated.exe. The server that boots had never been updated by its own script, which is why a second, never-booted install exists at C:\rustserver and why D:\rust is a wipe behind. Now reads +force_install_dir d:\rust\; the original is kept at D:\rust\start.bat.bak. D:\rust\steamapps\appmanifest_258550.acf was already present at the same buildid, so the first corrected run is a delta to the current wipe rather than a 5.9 GB re-download.
• C:\oxide_files is a 2025-04-23 Oxide and must not be copied anywhere. Oxide ships a patched Assembly-CSharp.dll; that bundle's is 6,842,880 bytes against the live 9,780,224, so copying it over a real install is a hard downgrade. D:\rust is already correct and needs nothing from it.

Rust force-wipes on the first Thursday of the month and Oxide is rebuilt to match, so "is the rig current" is a recurring question, not a one-time setup step. Every phase that touches the plugin re-checks it.

5. The phases

Phases 0–3 produce a working read-only Rust site. 4–5 are the permissions product. 6 is Teams. 7–8 are events. 9 is the optional tier. 10 is how any of it reaches somebody who is not us. Each phase ends with its findings written down, as every workstream here does.

#	Phase	Repos	Done when
0	The rig. Update to the current wipe (the script is fixed), confirm the Oxide build still matches, install the base set, prove a grant made at the console is visible to a plugin	docs	A current server boots with the base mods loaded and oxide.grant demonstrably gates something
1	Protocol 1 and three skeletons. Bounded drop-oldest queue, one writer thread, reconnect with a tagged epoch, dial-out; sidecar listener + SQLite + always-on token auth + version header; module from template/	all 3 + docs	One hello line travels game → sidecar → module, and killing the sidecar does not stall the game
2	The read path. First hook wave from HOOKS.md; events and snapshots kept distinct at the wire; wipe_id everywhere; every board re-emitted on connect	all 3 + docs	A restarted sidecar is fully populated within one connection, with no negotiation
3	The first pages. Server list, per-server status, killfeed, leaderboard; capabilities; nav	Module-rust	The site renders the last thing the game said while the game is off
4	Identity (R1)	3 + docs	A player links an account in-game and the site names their Steam ID
5	Site-owned permissions (R2). Groups and grants authored on the site; full set pushed on connect, deltas after; drift reported	all 3 + docs	A grant made on the website gates a third-party plugin in-game, and survives a wipe
6	Teams provider (R5). Rust's first-party clans; membership event-driven, leadership read off LocalClan at snapshot	Module-rust + 2	Core's reconciler is answered from live transitions, complete claimed only per reachable server
7	Events: one budget, one lease. kit ch. 5's own ordering — the lease before the action	Module-rust + 2	The leased value is observed changing in the running game and restored, per key
8	Events: the Kits reward action (R3)	all 3	A retried step grants loot once, and the ledger and the world agree
9	Optional mod integrations, the uMod Clans plugin first (R5). One adapter per plugin, each detecting via [PluginReference] and degrading to absent	rust-plugins + docs	A server missing every optional mod still runs the module, Teams included
10	The installer (R4). `--game servuo	rust, the bundle payload as a variant, an Oxide prerequisite check in doctor`, the protocol pairing refusal carried over	installer + docs
11	Docs, kit feedback, cutover	docs + Integration-kit	docs/ describes what shipped; R2's missing chapter answered either way

Why the lease comes before the reward action

The stated priority is Kits rewards, and this plan still schedules a lease first. kit ch. 5 is explicit about it and the reasoning survives restating: a lease is a value that already existed, changed for a while, and put back, so reading it first gives you the baseline for nothing. An action makes something that did not exist. The lease proves the whole command path — correlation, the idempotency key, budgetMs against the client timeout, the deadline the game enforces on its own — before anything hands out loot. It is a cheaper place to find all four of chapter 5's invisible failures.

Reversible on request.

What phase 8 must declare honestly

A kit grant cannot be reversible: 'ledger'. That value is a promise that core may come back and have the thing undone, on every terminal path including an abort — and there is no honest way to un-grant loot a player has already spent. The correct declaration is reversible: 'none', and saying so is the point: a capability that claims a reversal it cannot perform is the "capability that lies" chapter 5 names, and neither core nor review can catch it.

cost() must count the kits actually granted, derived from the params, every time. Core prices cost before dispatch and never reconciles it against what came back — it cannot, it does not know what a kit is — so an action that reports one while granting twelve turns an operator's cap of 30 into a cap of 360 with nothing anywhere going red.

And the monthly wipe is the case revert's tolerance rule was written for: every ledgered resource is invalidated at once, and "gone, and that is fine" is a success, not a failure.

6. Risks worth naming now

• Hooks bind by name and arity, by reflection, with no compile-time check. A misspelled hook is never called, silently, with no warning at load — the single most common way a Rust plugin does nothing. The plugin must log which of its expected hooks have fired at least once, so a hook Facepunch renamed on a wipe is visible rather than mysterious. See README.md §2.
• A convar that applies cleanly and does nothing. Most game config is read once at boot and cached; applying it later succeeds, reads back correctly, and changes nothing. Every lease key gets verified live — apply, observe in the running game, restore — before it is advertised. The UO module surveyed 156 config reads and found roughly eight that were live.
• The wipe cadence is the schedule. A monthly force wipe moves the hook list, rebuilds Oxide, and invalidates every ledgered resource. Phases that end near one should expect to re-verify rather than assume.
• start.bat's RCON password is letmein in plaintext with rcon.web 1. Acceptable on a loopback dev rig, and it must never be the shape anything published copies.