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date: 2026-08-26 sources: - direct Nexus/GitHub verification this session (gh api for alandtse/CrashLoggerSSE and alandtse/devbench release history; web search for Nexus mod pages, blocked from direct fetch by Cloudflare 403 — treated the same way docs/research/25 already did, as a routine bot-block, not evidence against a page's existence) - docs/decisions/0008-game-version-pin.md, docs/research/11-version-pin-and-transport.md - notes/skyrim-modlist-research/wabbajack-without-nexus-premium.md, .../ai-npc-dialogue-linux-compat.md (owner's personal-playthrough research, reused here only for the Proton/MO2 mechanics that carry over) - adapters/skyrim/ChronicleBridge/src/IdentityMap.cpp (read directly, not paraphrased) - docs/research/25-devbench-skse-mcp-verification.md, docs/research/24-programmatic-esp-authoring.md topic: "a concrete, from-scratch, minimal MO2 mod list for Chronicle/ChronicleBridge development and debugging, distinct from the owner's NGVO and Apostasy/Tuxborn personal-playthrough installs" status: filed

A Minimal, From-Scratch MO2 Mod List for Chronicle Development

Document File ID: docs/research/27-minimal-chronicle-dev-modlist.md Date: 2026-08-26

TL;DR

An 8-third-party-mod, hand-built MO2 instance (plus ChronicleBridge itself and the base game — no Wabbajack gallery list) satisfies every constraint this project actually has: the 1.6.1170/SKSE 2.2.6 pin, the 19-entry named-cast FormID table in IdentityMap.cpp, and DevBench-driven in-game verification. Downgrading to 1.6.1170 is still both necessary and available in 2026 — Bethesda's 1.7.99 (2026-08-20) is still the Steam default, and both the Steam-console download_depot method and at least three community patcher tools (two of them released after 1.7.99 specifically to handle this) remain live and maintained. One finding revises this task's own stated premise: IdentityMap.cpp does not only reference Skyrim.esm/HearthFires.esm — 2 of its 19 named-cast entries (idolaf_battle_born, lillith_maiden_loom) currently resolve, at runtime in NGVO, against unofficial skyrim special edition patch.esp (USSEP) as GetFile(0)'s owning plugin. Reading RE::TESForm::GetFile()/GetLocalFormID() in the local CommonLibSSE-NG checkout (see F3) shows this label is derived per-session from whichever plugins actually touched the record where the snapshot was taken — it is not necessarily "USSEP created this record," and it is not something header-reading alone can fully settle. What is actionable: the 19-entry table was captured with USSEP active, so this dev list should keep USSEP active too, to reproduce the exact environment the table was verified against, rather than risk a different (unverified, possibly different-localFormId) resolution for those two entries with USSEP absent. The recommended list is: USSEP → Address Library for SKSE Plugins → powerofthree's Papyrus Extender → PapyrusUtil SE → SSE Engine Fixes → CrashLoggerSSE → DevBench → ChronicleBridge (the project's own DLL) → SkyUI, all free, all currently 1.6.1170-compatible, small enough to install by hand-clicking Nexus downloads on a free account in under an hour — no Premium purchase and no Wabbajack needed at this mod count.

Findings

[F1] A downgrade step is still required and still available in 2026 — both the depot method and dedicated patcher tools. Nothing about ADR-0008's situation has changed: 1.7.99 (shipped 2026-08-20) remains Steam's default, and the whole native-plugin ecosystem (CrashLoggerSSE, DevBench, every AI-NPC framework) still targets 1.6.1170 as its baseline, adding 1.7.99 support as a parallel build rather than a replacement (see F5). Two live options: - Steam console download_depot. download_depot 489830 <depot> <manifest> for the three 1.6.1170 depots (489831/489832/489833, exact manifest IDs in docs/research/11-version-pin-and-transport.md) — cross-platform since it's just the Steam client's own console, not a third-party binary. This is the method already named in ADR-0008's lock procedure and needs no new verification. - Dedicated downgrade patchers, now a small but active sub-ecosystem. The "Steam 1.7.99 → 1.6.1170 → 1.5.97 Best of Both Worlds Downgrade Patcher" (Nexus #169962) applies BSDiff4 binary patches in place, preserves AE/Creation Club content, and was last updated 2026-01-16 — i.e. already maintained through the January patch cycle, not a stale pre-1.7.99 tool; its own page notes it's "only supported for Windows, though Linux users have reported success" (i.e. runs under Proton with mixed reports, not a guaranteed Linux path). Two more recent, more narrowly 1.6.1170-scoped tools surfaced in this pass: "SDT — Skyrim Downgrade Tool" (Nexus #188916, tagline "Downgrade from ANY version to 1.6.1170") and "Skyrim Downgrader" (Nexus #188956) — both newer listings than Best of Both Worlds, suggesting the tooling is still being actively iterated on post-1.7.99, not abandoned. None of the three Nexus pages could be fetched directly (Cloudflare 403, the same routine block docs/research/25 already documented — not evidence against existence; titles and metadata corroborated via search). - Recommendation: use download_depot for this list specifically, since it's already the procedure ADR-0008 committed to and documented, is native to Steam (no extra Windows binary to run under Proton), and this dev instance's Stock-Game copy (F2) needs the raw depot files anyway. Keep Best of Both Worlds / SDT as the documented fallback if download_depot manifest IDs ever go stale.

[F2] This list must NOT reuse NGVO's or Tuxborn's game copy — build a third, isolated Stock-Game instance. notes/skyrim-modlist-research/wabbajack-without-nexus-premium.md's "Stock Game / Game Root" pattern (every modern Wabbajack list copies the base game into its own MO2 folder, never touching the Steam install) is exactly the mechanism this dev list needs too, for the opposite reason the owner's personal lists use it: NGVO and Apostasy/Tuxborn are free to track whatever runtime their own lists specify, while this instance's entire reason to exist is staying locked to 1.6.1170 + SKSE 2.2.6 indefinitely. Build it as ~/Games/ChronicleDev/ (sibling to the existing ~/Games/NGVO and ~/Games/Tuxborn), with its own private copy of the 1.6.1170 depot files (via download_depot, F1) as the Game Root, its own MO2 portable instance pointed at that copy, and its own Proton prefix (a new non-Steam-game shortcut, same GE-Proton10-14 already installed and working for NGVO per tools/launch-ngvo-skse.sh). This guarantees a Steam auto-update to NGVO's or Tuxborn's copy (or an accidental Steam Play button click, the exact failure mode ADR-0008's lock procedure exists to prevent) can never touch this dev instance's files.

[F3] IdentityMap.cpp's two USSEP-attributed entries are real and reproducible, but the mechanism is subtler than "USSEP owns those records" — verified against CommonLibSSE-NG source, not just the code comment. Direct read of adapters/skyrim/ChronicleBridge/src/IdentityMap.cpp (kNamedCast, lines 48–68): 17 of 19 entries use "Skyrim.esm" or "HearthFires.esm" as pluginName, matching this task's stated "unmodified official masters only" premise — but two do not: {"unofficial skyrim special edition patch.esp", 0x01a689, "idolaf_battle_born"} and {"unofficial skyrim special edition patch.esp", 0x10e2b6, "lillith_maiden_loom"}. Cross-checking the raw snapshot these came from (adapters/skyrim/listener/whiterun-positions.json, read directly, not just the comment describing it) confirms both IDs verbatim: "unofficial skyrim special edition patch.esp:01a689" → Idolaf Battle-Born, "...:10e2b6" → Lillith Maiden-Loom. Both local IDs sit inside the same contiguous 0x01a6xx block as several Skyrim.esm-attributed neighbors (0x01a680 Anoriath, 0x01a684 Fralia, 0x01a685 Olfina, 0x01a68c Lars) — i.e. these are not USSEP-native FormIDs in USSEP's own allocation range (contrast the same snapshot's six "Whiterun Guard" entries, which do carry USSEP-native IDs like 0x037058 and 0x1000f7, clearly outside the vanilla actor block — genuine USSEP-created records). Reading RE::TESForm::GetFile()/GetLocalFormID() in the local CommonLibSSE-NG checkout (/home/geoff/projects/skyrim-re-toolkit/type-importer/vendor/CommonLibSSE-NG/include/RE/T/TESForm.h, lines 273–301) shows ResolveFormRef's form->GetFile(0) reads index 0 of the form's sourceFiles array — populated at runtime from whichever plugins actually touched that specific record in this load order/session — and GetLocalFormID() derives its masked local ID from that same file's compileIndex. This means the pluginName/localFormId pair this table hardcodes for these two entries is a function of the exact load order the snapshot was captured under (NGVO, USSEP active, 2026-08-24), not necessarily "USSEP created or owns the base record." Whether index 0 reflects the true originating master or an override-touched entry was not fully resolved by header reading alone in this pass — that would need either a live before/after capture with USSEP removed, or deeper CommonLibSSE-NG/engine-internals research, neither of which was attempted here. What is safe to act on regardless of that open question: this dev modlist should keep USSEP active, because that is the exact environment the current 19-entry table was verified against. Building this list without USSEP would put the two entries in an unverified state — at best a silent identity-resolution miss (falling through to FallbackIdentity()'s plugin:formid string instead of idolaf_battle_born/lillith_maiden_loom), at worst a different, also-untested (pluginName, localFormId) pair if GetFile(0) resolves differently once USSEP no longer touches those records. Either way, this revises this task's brief, which stated the table depends only on Skyrim.esm/HearthFires.esm — that premise doesn't hold for 2 of the 19 entries as currently observed, and should be flagged to the owner directly rather than silently corrected.

[F4] HearthFires.esm needs no special enabling step — it ships inside the AE base install, not as separate purchasable/optional content. Anniversary Edition bundles the three legacy DLCs (Dawnguard, Hearthfire, Dragonborn) directly into the base Data/ folder as of the AE re-release; they are not part of the opt-in Creation Club catalog. Any 1.6.1170 depot pull (F1/F2) already contains HearthFires.esm on disk, and MO2 auto-lists all masters found in its configured Data/ folder in the left pane, checked by default. The only failure mode worth watching for is a Stock-Game copy assembled from an incomplete depot set (missing the DLC-bearing depot) — verify HearthFires.esm is physically present in ChronicleDev/Game Root/Data/ once the depot pull finishes, before assuming it's fine.

[F5] Address Library for SKSE Plugins (Nexus #32444) is still the correct, current dependency name, and CommonLibSSE-NG's own posture treats it as necessary-but-not- sufficient — consistent with what ADR-0008 and docs/research/11 already concluded. This project's own prior research (docs/research/11, "Address Library alone does NOT save plugins... only handles function addresses, not class layout") already settled the substantive technical question; this pass found nothing that changes it. Address Library ships two builds on its Nexus page (the legacy SE "All-in-one" for 1.5.97, and a separate AE/1.6+ build) — ADR-0008's pin table already specifies "v11+" for the AE build, which is what this list needs. (Nexus page fetch blocked by the same Cloudflare 403 pattern noted throughout; the two-build split and version-independence design are corroborated by the CommonLibSSE-NG/community descriptions found via search and consistent with this project's own already-cited sourcing in docs/research/11.)

[F6] CrashLoggerSSE (alandtse) is real, current, and its release history shows the exact "1.7.99 added, 1.6.1170 kept" pattern this whole pin strategy depends on. Verified directly via gh api repos/alandtse/CrashLoggerSSE/releases: v1.25.0 (published 2026-08-21, one day after the 1.7.99 patch) whose changelog reads verbatim "Features: support Skyrim AE 1.7.99 (#42)" — an addition, not a replacement, matching the same pattern this project's own research already documented for CrashLoggerSSE's dependency SSE Engine Fixes and for DevBench itself (docs/research/25, v1.15.0 "support Skyrim AE 1.7.99" as an additive release). The prior release, v1.24.0 (2026-06-28), predates 1.7.99 entirely and is therefore unambiguously a 1.6.1170/AE-only build if a maximally conservative pin is wanted. Recommendation: install the current latest release (v1.25.0 or newer) — alandtse's own multi-year pattern across CrashLoggerSSE, DevBench, and SSE Engine Fixes is additive multi-version support in one build, not version-gated forks, so the newest release should still work on 1.6.1170; if a future release's changelog ever reads as a migration rather than an addition (dropping old-runtime support outright), fall back to pinning v1.24.0 specifically.

[F7] DevBench's MO2 install is exactly like any other SKSE-plugin mod — no special handling. Per docs/research/25 (already verified in depth: real repo, GPL-3 core + MIT integration glue, 127.0.0.1:8920 for SE/AE) plus this pass's confirmation of its install instructions: it installs like any Data-folder SKSE plugin (drop into MO2 as a normal mod, or extract to Data/ directly), with optional config at Data/SKSE/Plugins/devbench/config.json (bind address fixed to loopback, start port defaults to 8920, auto-advances if taken). Correction to docs/research/25's own framing, which assumed a separate Windows box reached over SSH: this project's actual deployment target (docs/architecture.md, "Skyrim SE/AE running under Proton on the same machine" as Chronicle's Linux service) means DevBench's 127.0.0.1:8920 is reachable directly from Chronicle's own Linux Python process with no SSH tunnel at all — the Proton prefix's loopback socket is the same machine's loopback, full stop. The SSH-tunnel scenario in docs/research/25 only applies if Chronicle's controlling process and the Skyrim/DevBench process are ever split across two physical machines (e.g. testing from a laptop against the Windows build machine) — not this list's actual use case.

[F8] SkyUI remains the standard, near-zero-risk QoL choice in 2026, and it's the only QoL mod this list needs. SkyUI (Nexus #12604) requires only SKSE (already a foundation of this list) — it does not use Address Library or any native-code version dependency, so it carries none of the patch-day fragility every other mod in this list is built around avoiding. It touches only the inventory/menu UI layer, has zero interaction surface with IdentityMap.cpp's named-cast NPCs or their AI packages, and is a dependency of a large fraction of the wider ecosystem (including, per notes/skyrim-modlist-research/ai-npc-dialogue-linux-compat.md, both Apostasy and Tuxborn) — familiar territory, not a new risk surface. Deliberately not recommending anything beyond this one QoL mod: a Papyrus log viewer is unnecessary since the Proton prefix's Documents/My Games/Skyrim Special Edition/Logs/Script/ directory is already directly visible to the Linux host (docs/architecture.md's own point about save/log visibility) — tail -f covers this need without installing anything. An in-game console/dev-tools mod is redundant with DevBench, which already exposes console-command execution programmatically (docs/research/25, §4) — installing a second console-enhancer mod would be adding a mod "because it's popular," exactly what this task asked to avoid.

[F9] No population/city-overhaul or NPC-replacer risk exists in this list by construction, but the constraint is worth stating explicitly for future sessions. None of the 9 mods recommended here touch NPC base records, AI packages, or Whiterun.esm-adjacent cell edits — the closest thing to a risk is USSEP itself (F3), and USSEP's own stated scope is bugfixes, not content redesign, and it is already the plugin IdentityMap.cpp depends on, not a new risk this list introduces. Flag for any future session extending this list: never add a city population mod (e.g. "Populated Cities," "Immersive Citizens," any Whiterun NPC replacer/AI overhaul) without first checking it against all 19 kNamedCast entries in IdentityMap.cpp — such a mod could re-point, delete, or renumber any of Braith/Carlotta/Amren/etc.'s FormIDs, silently breaking identity resolution the same way an absent USSEP would (F3), except worse (no fallback path if the base record itself is gone).

Recommendation

Build a new MO2 instance, ~/Games/ChronicleDev/, from scratch, isolated from NGVO and Apostasy/Tuxborn, with exactly this mod list:

# Mod Nexus / Source Role Load-order note
— Skyrim SE/AE 1.6.1170 Steam download_depot (F1/F2) Game version pin (ADR-0008) Stock-Game copy, not the Steam-managed install
— SKSE64 2.2.6 skse.silverlock.org Script extender loader Launch only via skse64_loader.exe
1 Unofficial Skyrim Special Edition Patch (USSEP) Nexus #266 Bugfix patch — load-bearing, not optional (F3) Near the top, standard USSEP position
2 Address Library for SKSE Plugins (AE build, v11+) Nexus #32444 Function-address resolution for every native plugin below No plugin/ESP; order-independent
3 powerofthree's Papyrus Extender Nexus #22854 ADR-0003's SAL reference-implementation dependency No plugin; order-independent
4 PapyrusUtil SE 4.6 Nexus #13048 ADR-0008 pin No plugin; order-independent
5 SSE Engine Fixes, Part 1, v6.1.1/6.2 (1.6.1170 build) Nexus #17230 ADR-0008 pin — stability substrate Part 1 installs as a normal MO2 mod; Part 2 must be extracted straight into the game's Data/ folder (it's a non-SKSE loose-file/.ini component the mod's own docs say bypasses MO2's virtual filesystem) — with this list's Stock-Game layout that means ChronicleDev/Game Root/Data/, not through MO2's Install Mod flow
6 CrashLoggerSSE (current release, F6) Nexus #59818 / github.com/alandtse/CrashLoggerSSE Crash logging for dev iteration No plugin; order-independent
7 DevBench (current release) Nexus #181326 / github.com/alandtse/devbench In-game MCP/REST test bench (F7) No plugin; near bottom
8 ChronicleBridge (this project's own .dll + .ini) built locally (.claude/windows-build-machine.md) The thing being tested No plugin; bottom of the left pane, wins any conflict
9 SkyUI Nexus #12604 Only QoL mod in the list (F8) Standard SkyUI position, after USSEP

Nine real mods plus the DLC-bearing base game — small enough to install by hand, clicking through Nexus's free-account manual-download flow in well under the "hundreds of clicks" problem notes/skyrim-modlist-research/wabbajack-without-nexus-premium.md documents for large Wabbajack lists. No Wabbajack, no Jackify, and no Nexus Premium purchase are needed for this list — that tooling exists to solve a large-list problem this deliberately small list doesn't have.

Build order: 1. Pin the game version first (F1/F2): pull the three 1.6.1170 depots into ~/Games/ChronicleDev/Game Root/ via download_depot, matching ADR-0008's already-documented manifest IDs. Verify HearthFires.esm is present (F4). 2. Install SKSE64 2.2.6 into that Game Root. 3. Set up a fresh, portable MO2 instance pointed at that Game Root — not a copy of NGVO's instance, not sharing its Proton prefix. Add a new non-Steam-game Proton shortcut for it (reuse the already-installed, checksum-verified GE-Proton10-14 per tools/launch-ngvo-skse.sh's header comments) with its own compat-data prefix. 4. Download and install mods 1–9 in the table above, in that order, via MO2's normal "Install Mod" flow (drag-and-drop archive or "Add from URL"). None of these are large files; a free Nexus account with manual clicking is a non-issue at this count. 5. Run LOOT once (cheap, harmless, and confirms nothing is flagged), even though a list this size barely needs sorting: the only two ESPs in the whole list are USSEP's and SkyUI's, and both have well-known, stable positions LOOT gets right automatically. Do not hand-tune further. 6. Drop ChronicleBridge.dll and its .ini into their own MO2 mod folder (mirroring how mod 7/8 above are installed — a plain SKSE/Plugins/ drop, no ESP), placed at the very bottom of the left pane per this project's own existing convention for winning file conflicts (see notes/skyrim-ai-modlist-plan.md's note on SkyrimNet's own bottom-of-pane placement for the same reason, applied here to Chronicle's own plugin instead). 7. Launch via MO2's moshortcut:// mechanism, the same pattern tools/launch-ngvo-skse.sh already established and fixed (unquoted title, waitforexitandrun) — write a launch-chronicledev-skse.sh twin once the instance exists, pointed at ChronicleDev instead of NGVO. 8. Verify DevBench is listening (Test-NetConnection-equivalent or a plain curl 127.0.0.1:8920/api/tools from the same Linux machine, no tunnel needed per F7) and that ChronicleBridge's own log shows it loaded, before running any of docs/design/chronicle-bridge-verification-runbook.md's steps.

Caveats

  • This pass could not directly fetch any Nexus mod page (Cloudflare 403 on every attempt) — every specific version/date claim about a Nexus-hosted mod (Address Library, USSEP, po3's Extender, PapyrusUtil, SSE Engine Fixes, SkyUI, CrashLogger, DevBench) is corroborated via web search snippets and/or this project's own already-verified prior research (ADR-0008, docs/research/11, docs/research/25), not a direct primary-source read of the Nexus page itself. The two GitHub-hosted facts (CrashLoggerSSE's and DevBench's actual release/changelog history) were read directly via gh api and are on firmer footing.
  • F3's underlying mechanism (why GetFile(0) reports USSEP for two records whose local IDs sit in the vanilla Skyrim.esm actor block) is not fully resolved — this pass verified TESForm::GetFile()/GetLocalFormID()'s literal implementation and cross-checked the raw snapshot JSON, which together rule out "USSEP-native record" (contrast the guards' distinct ID range) but don't conclusively establish whether index-0-of-sourceFiles means "originating master" or something else for a record USSEP has patched. The load-order- dependent conclusion (keep USSEP active to match the table's verified state) is actionable either way, but a future session with load-order-toggling access (capture the same snapshot with USSEP removed and diff the result) could settle this properly instead of leaving it as an open mechanism question. This is also a candidate docs/architecture.md FormID-rule concern worth a maintainer's attention on its own: if GetFile(0)'s answer for a record really does depend on which overriding plugins are active, that's exactly the load-order-dependent identity instability the FormID rule was written to guard against, one layer up from the raw-FormID-persistence case the rule already covers.
  • This report does not re-litigate the personal-playthrough Apostasy/Tuxborn/ Mantella research already filed in notes/skyrim-modlist-research/ — it reuses only the Proton/MO2 mechanics (Stock Game pattern, GE-Proton10-14, moshortcut launching) that generalize to any MO2 instance on this machine, not the modlist content choices themselves.
  • Exact current Nexus mod IDs for powerofthree's Papyrus Extender (#22854) and PapyrusUtil SE (#13048) and USSEP (#266) are carried over from this project's own established references (docs/architecture.md's SAL section, ADR-0008's pin table) rather than freshly re-verified against Nexus directly in this pass, for the same Cloudflare-403 reason noted above.

Sources