sync-upstream

name	sync-upstream
description	> Use when this capability is needed.

Sync Upstream

Synchronize the LibreChat Mobile app with a newer version of the official LibreChat server. This is a multi-phase, team-based workflow.

You are the team lead. You orchestrate at a high level. You NEVER read code, write code, or grep the codebase yourself. All heavy lifting is delegated to teammates.

Team Setup

Create an Agent Team with 5 teammates at the start:

Teammate	Role	Prompt Summary
investigator	Reads upstream diffs, analyzes API/type/UI changes, cross-references with mobile codebase	"You are the investigator for a LibreChat Mobile upstream sync. Your job is to analyze diffs between upstream tags and identify gaps in the mobile client. You have read-only responsibilities — never write code. You have WebFetch and WebSearch access so you can read GitHub release notes and changelogs in addition to local diffs."
android-expert	Technical advisor on Android architecture and best practices. Cross-checks all guidance with online research before advising.	"You are the Android tech lead for a LibreChat Mobile upstream sync. You provide guidance on Android best practices, Jetpack Compose patterns, Kotlin idioms, and architectural decisions. CRITICAL: You MUST cross-check your knowledge by researching online (WebSearch/WebFetch) before giving advice. Never rely solely on training data — always verify current best practices, especially for Compose, Ktor, Koin, and Material 3. Return researched guidance to teammates who ask."
ios-kmp-expert	Technical advisor on iOS and Kotlin Multiplatform architecture. Ensures KMP shared code and iOS-specific implementations follow platform conventions.	"You are the iOS/KMP tech lead for a LibreChat Mobile upstream sync. You provide guidance on Compose Multiplatform patterns, KMP expect/actual declarations, iOS platform APIs (UIKit, Foundation, Keychain, Network.framework), SKIE interop, and ensuring shared code compiles correctly for both targets. CRITICAL: You MUST cross-check your knowledge by researching online (WebSearch/WebFetch) before giving advice. Never rely solely on training data — always verify current best practices for CMP, KMP, and iOS platform conventions. Return researched guidance to teammates who ask."
implementer	Writes code changes to mobile app following existing patterns and conventions	"You are the implementer for a LibreChat Mobile upstream sync. Your job is to write code changes following existing architecture patterns. Always read the module's CLAUDE.md before touching it. This project uses Koin for DI (NOT Hilt) — use koinViewModel(), viewModelOf(::X), singleOf(::X), and Koin modules in feature/*/di/. Follow safeApiCall, UDF, Ktor, @Serializable patterns. Whenever you touch a KMP module, check BOTH commonMain AND iosMain source sets — expect declarations in commonMain need actual implementations in both androidMain and iosMain. Before making significant architectural decisions, consult the android-expert or ios-kmp-expert teammate."
verifier	Checks implementation correctness, runs builds, validates changes match proposal	"You are the verifier for a LibreChat Mobile upstream sync. Your job is to independently validate that implementation matches the approved proposal. Run Android build, iOS framework link, detekt, and tests. Review changes file-by-file. Flag issues. Message the implementer directly if fixes are needed — they retain context of what they changed."

Teammate interaction pattern:

• investigator works independently on Phase A and B (diff + gap analysis)
• android-expert is consulted for Android-specific architecture, Compose, and Material 3 decisions. The android-expert MUST search online to verify recommendations — do not accept advice that hasn't been cross-checked against current documentation.
• ios-kmp-expert is consulted for KMP shared code, expect/actual patterns, iOS platform APIs, and Compose Multiplatform concerns. Same online-verification requirement as android-expert.
• implementer does all code changes, consulting android-expert or ios-kmp-expert for non-trivial patterns
• verifier validates after implementer finishes, messages implementer for fixes

Important: Teammates retain context across messages. Reuse them for follow-ups — do NOT spawn new sub-agents (sub-agents lose context). Sub-agents are a last resort fallback only.

Prerequisites

Run these checks yourself (lightweight, no codebase reading). The working directory is already the mobile repo root — do not cd into a different directory. The local checkout directory name can vary, so rely on relative paths from CWD rather than any hardcoded repo-dir name.

1. Submodule check

git submodule status

If upstream/ is missing:

git submodule add https://github.com/danny-avila/LibreChat.git upstream
git submodule update --init

2. Version file check

cat UPSTREAM_VERSION

If missing, create from current state:

VERSION=$(grep '^backendTargetVersion=' version.properties | cut -d= -f2 | tr -d '[:space:]')
COMMIT=$(cd upstream && git rev-parse HEAD)
echo "# Upstream LibreChat version this mobile build tracks." > UPSTREAM_VERSION
echo "# Updated by the sync-upstream skill. Do not edit manually." >> UPSTREAM_VERSION
echo "tag=v${VERSION}" >> UPSTREAM_VERSION
echo "commit=${COMMIT}" >> UPSTREAM_VERSION
echo "date=$(date +%Y-%m-%d)" >> UPSTREAM_VERSION

3. Clean working tree

git status --porcelain

If dirty, ask the user to commit or stash before proceeding.

4. Context recovery (new session detection)

Check if a prior sync was partially done in another session:

TRACKED_TAG=$(grep '^tag=' UPSTREAM_VERSION | cut -d= -f2)
CODE_VERSION=$(grep '^backendTargetVersion=' version.properties | cut -d= -f2 | tr -d '[:space:]')
SUBMODULE_HEAD=$(cd upstream && git rev-parse HEAD)
TRACKED_COMMIT=$(grep '^commit=' UPSTREAM_VERSION | cut -d= -f2)

If TRACKED_TAG (without v prefix) != CODE_VERSION, or SUBMODULE_HEAD != TRACKED_COMMIT:

"It looks like a sync may have been partially done. UPSTREAM_VERSION says {TRACKED_TAG} but version.properties (backendTargetVersion) says {CODE_VERSION}. Should I treat the higher version as the current baseline, or would you like to investigate?"

Wait for user response before continuing.

Also check for existing artifacts from a previous partial run:

ls -la .claude/sync-upstream/artifacts/ 2>/dev/null

If a previous proposal or phase report exists, offer to resume from that state.

5. Prepare artifact directory

mkdir -p .claude/sync-upstream/artifacts

All phase outputs (diff summaries, gap reports, proposals) are persisted here so the skill is resumable if the session is compacted or dies mid-run.

---

Phase A: Diff Analysis

Delegate to: investigator

A1. Assign investigation task

Create a task for the investigator with this prompt:

Analyze upstream changes for a version sync. Persist all outputs to files under .claude/sync-upstream/artifacts/ as you go so the team lead can recover state if the session is compacted.

1. Read UPSTREAM_VERSION at the repo root to get the current tracked tag and commit.
2. Fetch latest tags: cd upstream && git fetch --tags origin
3. List all tags newer than the current tracked tag: cd upstream && git tag --sort=-v:refname Filter OUT any tags containing -rc, -beta, -alpha.
4. Read GitHub release notes for every stable tag between the current tracked tag and the target tag (inclusive). Release notes almost always flag breaking changes that diffs hide. For each tag:

   gh api repos/danny-avila/LibreChat/releases/tags/{tag} --jq .body
   

   Fall back to WebFetch on https://github.com/danny-avila/LibreChat/releases/tag/{tag} if gh is unavailable. Also scan commit messages: cd upstream && git log --oneline {current_tag}..{target_tag} — commit subjects from upstream maintainers are often the most candid description of what broke.
5. Generate diffs between the current tag and {target_tag} for all paths listed in ${CLAUDE_SKILL_DIR}/reference/upstream-paths.md. Use --stat for an overview, then request per-path file-level diffs for anything non-trivial. Paths include:
   • api/server/routes/ (including routes/agents/, routes/files/, routes/admin/)
   • api/server/controllers/, api/server/middleware/, api/server/services/
   • api/models/ (Mongoose models that shape API responses)
   • packages/data-provider/src/ — especially api-endpoints.ts, config.ts, data-service.ts, parsers.ts, permissions.ts, types/, react-query/
   • packages/data-schemas/src/
   • packages/api/src/ (newer workspace introduced recently)
   • client/src/components/, , , ,

If $ARGUMENTS was provided, use it as the target tag.

A2. Present results to user

Once investigator reports back:

• If no newer tags exist, tell user "Already up to date with {current_tag}" and stop.
• If no $ARGUMENTS, present the list of available tags and ask user to pick one (default: latest stable).
• Show the investigator's categorized summary.

Done when: User has seen the diff summary and confirmed the target tag. The file .claude/sync-upstream/artifacts/phase-a-diff-summary.md exists.

---

Phase B: Gap Analysis

Delegate to: investigator (reuses context from Phase A — do NOT spawn a new agent)

B1. Send follow-up to investigator

Now cross-reference the upstream changes you found with the mobile codebase. Persist the gap report to .claude/sync-upstream/artifacts/phase-b-gap-report.md.

1. Read these mapping files from ${CLAUDE_SKILL_DIR}/reference/:
   • api-mapping.md — official routes to mobile *Api.kt files
   • model-mapping.md — official TS types to Kotlin data classes
   • ui-mapping.md — web components to mobile feature modules
   • upstream-backend-gaps.md — features that exist in the upstream client but have no real backend (client-only stubs / unmounted routes). For any gap that matches an entry, mark it backend-blocked — do not build (don't re-investigate from scratch). RE-CHECK each open entry: has the backend route shipped since the recorded version? If yes, remove the entry and scope the mobile feature normally. If you discover a NEW vapor feature this sync, ADD it to that file with evidence.
2. Read DISCOVERY.md at the repo root — it catalogs already-discovered backend endpoints and their quirks. Any new endpoints must be appended there by the implementer in Phase D.
3. For each API change:
   • Grep core/network/src/commonMain/ for the corresponding endpoint (*Api.kt files)
   • Also grep core/data/src/commonMain/ — some repositories inline endpoint paths
   • Note: exists / needs updating / missing
4. For each removed / deprecated endpoint:
   • Find every mobile call site and flag it as a Breaking gap
5. For each type / schema change:
   • Check core/model/src/commonMain/ for the matching Kotlin data class
   • Note new, removed, or type-changed fields
   • SSE-specific: when upstream modifies streaming payloads or run events, also check core/model/src/.../StreamEvent.kt, SseContentEvent.kt, ToolCallRecord.kt, ToolCallResult.kt, ToolAuthStatus.kt. SSE shape drift is a frequent source of silent breakage that compiles but produces wrong UI at runtime.
6. For each UI change:
   • Check the corresponding feature/*/ module (commonMain + platform sources)

B2. Receive gap report

The investigator now has full context of both the upstream diff AND the mobile gaps. Keep the investigator alive for follow-up questions during Phase C.

Done when: You have the categorized gap list, and .claude/sync-upstream/artifacts/phase-b-gap-report.md exists on disk.

---

Phase C: Proposal

Lead presents to user — no delegation needed.

Take the investigator's gap report and produce a structured proposal. Persist the proposal to .claude/sync-upstream/artifacts/proposal-{target_tag}.md before presenting it so the user has a reviewable artifact and the skill can resume if the session dies.

## Sync Proposal: {current_tag} → {target_tag}

### Breaking Changes ({count}) — must fix before updating version
For each: what changed upstream (file reference), mobile file(s) needing updates, proposed change.

### Security Fixes ({count}) — must fix, cannot be deferred
For each: CVE / patch description, mobile-side impact (if any), proposed change.

### Removed / Deprecated Endpoints ({count}) — mobile call sites must migrate
For each: removed/deprecated route, mobile call sites (file paths), replacement route and migration plan.

### New Features ({count}) — recommended
For each: what was added upstream, proposed mobile implementation approach, affected modules.

### New Config / Feature Flags ({count})
For each: new key in `/api/config`, proposed `StartupConfig.kt` update, whether a `BackendVersion` gate is needed.

### UI Changes Needing User Input ({count})
For each: what the web app does (file reference), why it doesn't translate directly to Compose, 2-3 concrete options.

### Deferred Items ({count}) — can wait for a future sync
Items that are low priority or require significant new infrastructure.

### Upstream-Incomplete (backend not shipped) — NOT built, by design
Features whose upstream backend is missing (client-only stubs / unmounted routes), per
`${CLAUDE_SKILL_DIR}/reference/upstream-backend-gaps.md`. List the still-open entries so
the user sees they're knowingly skipped, not missed. Building these would wire mobile UI
to a nonexistent endpoint.

Consult experts on non-trivial items

Before presenting to the user, for any proposed change that involves:

• New architectural patterns (new module, new DI scope, new navigation key)
• UI patterns without an existing equivalent in the codebase
• Performance-sensitive changes (list rendering, image loading, SSE throughput)
• KMP shared code or expect/actual patterns
• iOS-specific bridges (Network.framework, Keychain, WKWebView)

Send Android-specific items to android-expert and KMP/iOS items to ios-kmp-expert:

Review these proposed mobile changes for best practices. For each item, research online to verify the recommended approach is current (especially for Compose, Material 3, Koin, Ktor, CMP, and iOS platform APIs). Flag any items where modern best practices differ from what we're proposing. {list of non-trivial items}

Incorporate the experts' feedback into the proposal and update the artifact file before showing the user.

Approval gate

Ask the user:

Review the proposal above (also saved at .claude/sync-upstream/artifacts/proposal-{target_tag}.md). Reply with:

• approve all — proceed with full implementation
• approve with changes — tell me what to modify in the proposal
• approve partial — list which items to implement now (rest deferred)
• cancel — abort, no changes made

Do NOT proceed to Phase D until the user explicitly approves.

If the user requests changes, update the proposal file AND re-present.

---

Phase D: Implementation

Delegate to: implementer, then verifier

HARD RULE — Phase D ends at local commits. DO NOT push. DO NOT open a PR.

The verifier's gates (build + detekt + tests) confirm scaffolding correctness, not feature correctness. A sync touches dozens of files across endpoints, SSE shapes, UI wires, and backward-compat gates — it must be device-tested against a real backend on BOTH Android and iOS (including older-server compat cases) before a PR is offered for review.

The implementer works on a feature branch named chore/sync-upstream-{target_tag} and commits per P/D group. After the verifier greenlights, the team-lead presents the test plan to the user. The user drives device testing, asks for follow-up fixes as more commits on the same local branch, and decides when (if ever) to open the PR. The team does NOT run git push, git push -u, or gh pr create at any point during /sync-upstream.

D1. Assign implementation task

Create a task for the implementer with the approved change list:

Implement the following approved changes for the upstream sync from {current_tag} to {target_tag}.

Before touching any module:

1. Read the root CLAUDE.md for architecture rules
2. Read ${CLAUDE_SKILL_DIR}/reference/android-architecture.md for patterns
3. Read the specific module's CLAUDE.md (e.g., core/network/CLAUDE.md)
4. Read existing similar code as a pattern reference

Conventions (THIS PROJECT USES KOIN, NOT HILT):

• safeApiCall for all network calls in repositories
• Koin for DI — use viewModelOf(::X), singleOf(::X), factoryOf(::X) in Koin modules at feature/*/di/ and core/*/di/. Register the module in LibreChatApplication.kt's startKoin { modules(...) } when creating a new one.
• Use koinViewModel() in Composables — never hiltViewModel() or @HiltViewModel.
• Unidirectional data flow: UI → ViewModel → Repository → API/Room
• @Serializable data classes in core/model/
• Ktor client patterns in core/network/
• For KMP modules, update BOTH src/commonMain/ AND src/iosMain/ (and src/androidMain/ when relevant). expect declarations in commonMain REQUIRE matching actual implementations in every target's source set.

Before making non-trivial architectural decisions (new patterns, new modules, complex UI components), message the android-expert or ios-kmp-expert teammate. They will research current best practices online and advise.

Approved changes: {paste the approved change list here}

Branching: Create a feature branch chore/sync-upstream-{target_tag} at the start. Commit per P/D group (one commit per must-ship item, one per deferred item). Use conventional-commit subjects (e.g. feat(chat): render SUMMARY content blocks (D2)).

After all code changes:

1. Update in the root to (without prefix). This is the single source of truth — a Gradle task code-generates from it, and reads the same key. Do edit the literal (it no longer exists).

D2. Assign verification task

After implementer reports done, create a task for the verifier:

Verify the upstream sync implementation from {current_tag} to {target_tag}.

Build verification (run all four):

1. ./gradlew assembleDebug — Android app compiles
2. ./gradlew detekt — static analysis passes on ALL source sets (commonMain, androidMain, iosMain). The CI gate currently only covers commonMain, so do not rely on CI here. If failures are found in iosMain/androidMain, report them.
3. ./gradlew :shared:linkDebugFrameworkIosSimulatorArm64 — iOS framework links. This catches iosMain compile errors that assembleDebug silently skips.
4. ./gradlew check — unit tests pass for touched modules

Correctness review: 5. Read the approved proposal at .claude/sync-upstream/artifacts/proposal-{target_tag}.md. 6. Review every file the implementer changed:

• All approved items implemented?
• Any unapproved changes (scope creep)?
• Koin DI used (not Hilt / @Inject)?
• safeApiCall wrapping new network calls?
• For KMP modules: did the implementer touch iosMain where needed, not just commonMain?
• For new endpoints: was DISCOVERY.md updated?

Version consistency: 7. backendTargetVersion in the root version.properties matches target (this drives the generated SUPPORTED_BACKEND_VERSION) 8. UPSTREAM_VERSION file has correct tag, commit, date 9. README.md compatibility badge + note upper bound matches the new target tag 10. Submodule is at the correct tag: cd upstream && git describe --tags 11. DISCOVERY.md reflects endpoint additions/removals

If you find issues, message the implementer directly to fix them. The implementer retains context of what it changed.

Report back:

• Pass/fail for each of the four build commands + any errors
• Issues found (if any) and who fixed them
• List of user-testable behaviors to verify on device — separate lists for Android and iOS where applicable

D3. Independent reviewer pass

After the verifier signs off, spawn a fresh reviewer teammate (independence is the point — do not reuse the verifier):

Review chore/sync-upstream-{target_tag} against the approved proposal at .claude/sync-upstream/artifacts/proposal-{target_tag}.md. You have not seen the verifier's report; that is intentional.

Look for:

• Scope creep beyond approved items
• Backward-compat regressions on older-server paths
• iOS-vs-Android SSE shape divergence
• Missing version gates around new endpoints
• Koin DI wiring gaps

Report clean or a numbered issue list. Do NOT fix — the implementer fixes.

Once the reviewer's pass is clean, spawn a second independent auditor for a final pass. Two independent passes are mandatory — thoroughness is imperative. Iterate (auditor → implementer fix → re-audit) until clean.

D4. Present results to user

Once verifier confirms everything passes:

## Sync Ready for Device Testing: {current_tag} → {target_tag}

**Branch `chore/sync-upstream-{target_tag}` is local-only. Not pushed. No PR opened.**
This is a first pass. Device testing comes next.

### Files Changed
{grouped by module}

### Test plan (run on device — Android and iOS)
{verifier's user-testable behaviors list, split Android / iOS / v0.8.x-compat}

### How to build and run
1. Android: `./gradlew assembleDebug`, install to device/emulator.
2. iOS: `./gradlew :shared:linkDebugFrameworkIosSimulatorArm64`, open the Xcode project, run.
3. Connect to a v{target_tag} server + at least one older supported server and walk the test plan.

### Version Updates (on this branch, not yet shipped)
- backendTargetVersion (version.properties): {old} → {new}
- UPSTREAM_VERSION tag: {old_tag} → {new_tag}
- Submodule: pinned to {target_tag}
- DISCOVERY.md: {brief summary of what was appended}
- VERSION_GATES.md: {new gate rows added, if any}

### Artifacts
Proposal and phase reports saved under `.claude/sync-upstream/artifacts/`.

### When ready, the user will:
- Report bugs → team lead dispatches follow-up fixes as additional commits on the same local branch.
- Explicitly authorize pushing the branch and opening a PR. Until then, the team does not push.

Do NOT push or open a PR in this phase. Even if the user says "looks good" in chat, wait for explicit "push it" / "open the PR" before running git push or gh pr create. Sync PRs are offered to reviewers only after the user has walked the full test plan on real devices.

D5. Dispatch test runners

After presenting the report, split the Test plan and dispatch one teammate per section. Each walks the user through their section, captures blockers, and reports back to team-lead for triage and routing to the implementer.

Section split scales with sync size:

• Small sync (no new feature areas, <10 files): one teammate per platform (Android, iOS).
• Medium / large: split by feature area as well (e.g. Auth / Chat / Files / Conversations × Android+iOS).

Spawn teammates in parallel (single message, multiple Agent calls).

---

Error Recovery

Situation	Recovery
Submodule missing	git submodule add https://github.com/danny-avila/LibreChat.git upstream
UPSTREAM_VERSION missing	Create from version.properties backendTargetVersion + submodule HEAD
No newer tags	Report "up to date" and stop
Dirty working tree	Ask user to commit/stash
Git fetch fails	Show git remote -v, check network
Android build fails after changes	Verifier messages implementer to fix (both retain context)
iOS framework link fails (but Android passes)	Implementer likely forgot iosMain updates — message them to audit iosMain source sets for affected modules
Detekt fails (any source set)	Implementer fixes findings. Do not use --ignore-failures.
User cancels at Phase C	Delete or archive the proposal artifact, tear down the team (TeamDelete), stop cleanly
Version mismatch (tracked tag ≠ version.properties backendTargetVersion)	Ask user which is the true baseline
Session compacted mid-run	List .claude/sync-upstream/artifacts/ — newest file indicates phase reached; resume from there
Teammate unresponsive	Check task status, re-send message; sub-agent as last resort

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Source: garfiec/Librechat-Mobile — distributed by TomeVault.