# AGENTS.md — Build guide for Obsidian Sync ## Project scope Keep an existing Markdown vault portable, choose one supported sync route and retain conflict copies plus independent backups when devices diverge. Catalogue verdict: yes. If you already accept local Markdown files, syncing folders across devices is a solved problem; the hard part is not the app, it is conflict-free convenience. Use the implementation prompt below to define the deliverable. Complete each phase's acceptance checks before extending the scope. ## Working agreement - Inspect the repository and its existing instructions before choosing paths, dependencies or commands. Keep one coherent stack and explain changes to the proposed architecture. - Plan a vertical slice that accepts a real input and produces the useful output described below. Persist only the state the prompt calls for; respect memory-only and upstream-managed workflows. Use fixtures only when they are clearly labelled. - After scaffolding, document the actual install, development, check and build commands in README and keep them synchronized with the package or project manifest. Do not report commands as successful unless they ran. - Work in small steps. At handoff, list implemented flows, checks actually performed, remaining blockers, and any credentials or provider setup the owner must supply. - Do not publish, spend money, contact customers, delete source data or run irreversible migrations without the project owner's authorization. ## Prerequisites - Runtime and tools: A Node watcher with chokidar and simple-git around an existing Markdown vault; no web server or application database. - Before starting: Git, one existing vault, a private remote, configured credentials and a second disposable vault for the documented conflict walkthrough. ## Stack and architecture - A Node watcher with chokidar and simple-git around an existing Markdown vault; no web server or application database - Data design: Store VaultPath, SyncBackendConfig, FileSnapshot and ConflictRecord; never run two sync engines on the same vault and never resolve divergent edits by silent last-writer-wins deletion. - Setup: Git, one existing vault, a private remote, configured credentials and a second disposable vault for the documented conflict walkthrough ## Security and data integrity - Debounce local edits, serialize sync operations and retain both sides of conflicts. A sync is not a backup; document independent restore points and exclusions. - Preserve the existing Git-oriented local workflow where chosen, but do not advertise it as encrypted managed sync. Git history, deleted files and sync providers each have different privacy/retention behavior. - Keep secrets outside client bundles and exported projects; document what leaves the device and make retention/deletion controls visible. ## Agent implementation rules - Project rule — domain: Store VaultPath, SyncBackendConfig, FileSnapshot and ConflictRecord; never run two sync engines on the same vault and never resolve divergent edits by silent last-writer-wins deletion. - Project rule — scope and recovery: Preserve the existing Git-oriented local workflow where chosen, but do not advertise it as encrypted managed sync. Git history, deleted files and sync providers each have different privacy/retention behavior. - Project rule — acceptance: Edit the same note offline on two devices and reconnect; preserve both versions, surface a merge task and restore a prior attachment from backup. - Project rule — delivery: document real setup commands and permissions; do not claim a build, accuracy level, performance result or security certification that has not been demonstrated. ## Optional agent skills and references - Recommended skill: [sharp-edges](https://github.com/trailofbits/skills/blob/main/plugins/sharp-edges/skills/sharp-edges/SKILL.md) — review configuration and API defaults against the app-specific invariants and recovery boundaries above; this is not a security certification. Follow the maintainer's installation instructions and match its requirements to the chosen runtime. Read the linked SKILL.md and its dependencies before adding a skill. Select only the skills matching this project's runtime and task; their documentation does not supply API access, credentials or approval to perform external actions. Pin the reviewed revision where the tool supports it. Follow the chosen agent's documented project-level installation mechanism. ## Distribution ideas These are optional planning notes. Obtain the owner's approval before publishing or contacting anyone. - Demonstrate this working slice using synthetic or explicitly authorized non-sensitive examples: Keep an existing Markdown vault portable, choose one supported sync route and retain conflict copies plus independent backups when devices diverge. - Share a synthetic example export and the acceptance walkthrough; keep real customer, health, financial and source data private: Edit the same note offline on two devices and reconnect; preserve both versions, surface a merge task and restore a prior attachment from backup. - State the limits before asking someone to replace their existing tool: Preserve the existing Git-oriented local workflow where chosen, but do not advertise it as encrypted managed sync. Git history, deleted files and sync providers each have different privacy/retention behavior. ## Engineering roadmap 1. Phase 1 — Pin the working slice and create its example input: Keep an existing Markdown vault portable, choose one supported sync route and retain conflict copies plus independent backups when devices diverge. Confirm setup: Git, one existing vault, a private remote, configured credentials and a second disposable vault for the documented conflict walkthrough. 2. Phase 2 — Document authoritative storage and configure these safeguards in the existing tools: Store VaultPath, SyncBackendConfig, FileSnapshot and ConflictRecord; never run two sync engines on the same vault and never resolve divergent edits by silent last-writer-wins deletion. 3. Phase 3 — Configure the existing tools and document status/troubleshooting without building another app. Debounce local edits, serialize sync operations and retain both sides of conflicts. A sync is not a backup; document independent restore points and exclusions. 4. Phase 4 — Expose the app-specific limits and recovery path in context: Preserve the existing Git-oriented local workflow where chosen, but do not advertise it as encrypted managed sync. Git history, deleted files and sync providers each have different privacy/retention behavior. 5. Phase 5 — Walk through this concrete acceptance case and preserve its exported evidence: Edit the same note offline on two devices and reconnect; preserve both versions, surface a merge task and restore a prior attachment from backup. Finish the README and backup/restore instructions; report unfinished capabilities explicitly. ## Paid-product capabilities outside this build - official mobile sync polish - conflict handling - version history UI - encrypted vault workflow - Obsidian support ## Implementation prompt Build the following focused alternative to Obsidian Sync. Implement the focused workflow below first; the verdict is not evidence of a completed or production-certified build. WORKING SLICE Keep an existing Markdown vault portable, choose one supported sync route and retain conflict copies plus independent backups when devices diverge. SETUP AND ARCHITECTURE Use A Node watcher with chokidar and simple-git around an existing Markdown vault; no web server or application database. Prerequisites: Git, one existing vault, a private remote, configured credentials and a second disposable vault for the documented conflict walkthrough. Before integrating anything, record actual versions and permissions, plus model files or provider limits only where used, in the README; make unavailable dependencies visible rather than simulating success. DOMAIN MODEL AND INVARIANTS Store VaultPath, SyncBackendConfig, FileSnapshot and ConflictRecord; never run two sync engines on the same vault and never resolve divergent edits by silent last-writer-wins deletion. IMPLEMENTATION CONTRACT Debounce local edits, serialize sync operations and retain both sides of conflicts. A sync is not a backup; document independent restore points and exclusions. Provide an operator checklist, the exact configuration files and a status/troubleshooting procedure in the existing tools; do not create a new application UI. Preserve the last saved state if a job or save fails. Include empty, loading, permission-denied, partial and retryable-error states. Log identifiers and error categories without secret values or unnecessary private content. APP-SPECIFIC BOUNDARY AND RECOVERY Preserve the existing Git-oriented local workflow where chosen, but do not advertise it as encrypted managed sync. Git history, deleted files and sync providers each have different privacy/retention behavior. ACCEPTANCE SCENARIO Edit the same note offline on two devices and reconnect; preserve both versions, surface a merge task and restore a prior attachment from backup. Also resume the configured workflow after an interrupted operation, confirm the saved record/export remains inspectable, and document the recovery action. These are implementation acceptance requirements, not a claim that this guide has been tested. DELIVERY Deliver a setup/runbook folder with configuration examples, permission instructions, troubleshooting steps, an independent backup/restore procedure and the exact acceptance walkthrough. Keep using the existing applications and their data formats; do not scaffold an unrelated app or database. Implement the working slice before optional integrations; list any deferred paid-product capabilities honestly. Do not add capabilities outside the working slice just to resemble the original product. PROJECT RULES FOR AGENTS.md Keep the domain invariants above executable at the write boundary. Propose scope changes before adding providers or permissions. Never fabricate source evidence, publish results, identity matches or successful delivery. Preserve user originals and require an explicit confirmation for destructive changes or external publication. ## Completion evidence Demonstrate the prompt's acceptance scenarios against the scoped workflow. Include setup from a clean checkout and failure recovery. Check persistence across restart and export/restore only for the state the prompt says to store; for memory-only tools, confirm that temporary content is discarded as specified. Record actual results and remaining limitations. A detailed plan alone does not establish a working replacement.