Vault Mirror Skill

Project-instruction file resolution: CLAUDE.md and AGENTS.md (Codex CLI) are transparent aliases — see skills/_shared/instruction-file-resolution.md. When this skill mentions Session Config in CLAUDE.md, the alias rule applies.

Purpose

vault-mirror populates the Meta-Vault with machine-generated notes derived from structured JSONL records. It converts entries from .orchestrator/metrics/sessions.jsonl and .orchestrator/metrics/learnings.jsonl into vault-conformant Markdown files under numeric-prefix subdirectories. This is distinct from vault-sync, which validates the vault — vault-sync validates the vault; vault-mirror populates it. The two skills are complementary: vault-mirror writes notes, vault-sync checks that the vault as a whole remains conformant.

When Invoked

vault-mirror is called in two places:

• Phase 3.7 of session-end (skills/session-end/session-metrics-write.md) — mirrors the sessions.jsonl entry for the closing session.
• Phase 3.5 of evolve (skills/evolve/SKILL.md) — mirrors all learnings.jsonl entries added during the evolve cycle.

Both call sites are conditional: vault-mirror runs only when vault-integration.enabled == true AND vault-integration.mode != "off" in the project's Session Config. When either condition is not met, the call site skips silently and vault-mirror is never invoked.

Inputs

scripts/vault-mirror.mjs is the implementation. All arguments are required except --dry-run.

Flag	Type	Required	Description
--vault-dir	path	yes	Absolute path to the Meta-Vault root directory. Must exist.
--source	path	yes	Path to the JSONL file to read (one JSON object per line). Must exist.
--kind	session or learning	yes	Determines which generator and target path are used.
--dry-run	flag	no	Parse and resolve paths but do not write any files. Emits action lines as normal.

Empty lines in the JSONL source are silently skipped.

Outputs

One JSON line is written to stdout for each non-empty JSONL entry processed. Exit code reflects the run outcome.

Action values

action	Meaning
created	Entry did not exist in the vault; file created.
updated	Entry existed (generator marker present, same id) with an older updated date; file overwritten.
skipped-noop	Entry existed, same id, updated date not advanced; file unchanged.
skipped-handwritten	A file at the target path has no _generator marker (or an unknown generator); left untouched.
skipped-collision-resolved	A file at the target path has the generator marker but a different id; a disambiguated slug was used instead.
skipped-invalid	Entry is missing one or more required fields; entry skipped, processing continues.
skipped-quality-low	Entry failed the quality gate (PRD F1.2): learning confidence below vault-mirror.quality.min-confidence (CLI: --quality-min-confidence, default 0.5), or session rendered-narrative length below vault-mirror.quality.min-narrative-chars (CLI: --quality-min-narrative-chars, default 400). The emitted JSON line includes a reason field describing the violated threshold and path: null (no file was created). The quality gate runs before --force; --force does not bypass it.

Output line shape

{"action":"created","path":"50-sessions/session-orchestrator/session-2026-04-13.md","kind":"session","id":"session-2026-04-13"}

path is relative to --vault-dir.

Exit codes

Code	Meaning
0	Success (including idempotent no-ops and per-entry skips).
1	Malformed JSON on a JSONL line — fatal, processing stops. Also returned when required CLI args are missing.
2	Filesystem error: --vault-dir not found, --source not found, or an unexpected write error.

Target Paths

Kind	Target
session	<vault-dir>/50-sessions/<repo>/<session-id>.md
learning	<vault-dir>/40-learnings/<repo>/<slug>.md

Subdirectories are created automatically with mkdirSync({ recursive: true }) when writing (not in --dry-run mode).

The numeric prefix (50-sessions/, 40-learnings/) follows the vault folder ordering convention so that sessions and learnings appear in the correct position in the vault tree relative to other note types.

Per-project namespacing (#660). New writes are namespaced under a per-repo subdirectory <repo>/, so a single shared vault can hold notes from multiple projects without cross-repo slug/id collisions. <repo> is resolved by resolveRepoNamespace() (scripts/lib/vault-mirror/namespace.mjs): the optional vault-integration.vault-name Session Config key (CLI: --vault-name) when set, else the git-origin repo slug via deriveRepo(), sanitised to a single kebab segment. Owner-privacy leaks (personal home path / private project slug / personal name) are redacted to redacted-repo before any write. The legacy flat layout (40-learnings/<slug>.md) is still read — the writer dual-probes the flat path so a pre-existing flat note is never duplicated; a one-time relocation of the historical flat corpus is tracked as a follow-up.

Path contract note: Issue #187 shipped the flat numeric-prefix layout (deferring the per-<repo> subfolder it sketched). Issue #660 adds that per-repo subfolder for write-isolation (above) while keeping the numeric-prefix ordering. If you need a different layout, file a new issue — do NOT silently change the script.

Learning-coverage self-healing after a store recovery (#740). vault-mirror always mirrors the CURRENT learnings.jsonl store contents at run time — if an earlier session's store was truncated or corrupted and later recovered (e.g. from a .bak), the resulting transient coverage gap in the vault is closed automatically by the next mirror run, with no manual backfill required. Note also that vault-mirror.quality.min-narrative-chars (see Failure Modes → skipped-quality-low below) gates sessions only — processLearning never applies a narrative-length filter, so a short learning insight is never skipped for length; only the confidence gate (vault-integration.quality.min-confidence) applies to learnings.

Host-local pseudonym mapping (Epic #725 D5). Without a map, EVERY owner-leaky repo namespace collapses to a single redacted-repo/ subdir — which breaks the #660 write-isolation (N private repos share one directory → id/slug collisions) and destroys cross-repo attribution. A host-local pseudonym map fixes this: each real repo slug is assigned a stable, non-leaky pseudonym, so the vault gets 40-learnings/<pseudonym>/ (and matching source-repo frontmatter, via W2's attribution threading) instead of everyone landing in redacted-repo/. The map is a JSON object { "real-slug": "pseudonym-slug", … } at a host-local path referenced by owner.yaml → paths.namespace-map-path (env SO_NAMESPACE_MAP overrides; precedence env > owner.yaml > unset). resolveRepoNamespace() consults the map ONLY at the redaction site (i.e. only when a repo would otherwise be redacted), looking up both the sanitised segment and the raw identifier; a hit returns the pseudonym and skips redaction, so clean/public repos never touch the map (or its lazy owner.yaml read). Privacy guarantee: the map file lives OUTSIDE every repo (alongside owner.yaml under ~/.config/session-orchestrator/) and is never committed — only the pseudonyms reach the vault, the real names stay host-local. Each pseudonym is validated (must be a kebab slug AND must not itself be owner-leaky); invalid or leaky pseudonyms are dropped with a WARN. Fallback: an absent, unreadable, or malformed map — and any UNMAPPED owner-leaky repo — still redacts to redacted-repo, identical to pre-#725 behaviour. Implementation: scripts/lib/vault-mirror/pseudonym-map.mjs (loadPseudonymMap) + namespace.mjs.

Idempotency

vault-mirror is safe to run multiple times against the same JSONL source:

1. No file exists → create.
2. File exists, _generator marker present, same id, updated date not advanced → skipped-noop, file unchanged.
3. File exists, _generator marker present, same id, updated date advanced → updated, file overwritten.
4. File exists, no _generator marker → skipped-handwritten, file untouched. The absence of the marker means the file was written by a human and must not be overwritten automatically.
5. File exists, _generator marker present, different id → slug collision. A disambiguated slug is derived by appending -<first-8-chars-of-entry-uuid> (hyphens stripped from the UUID before taking the prefix). The original file is left unchanged; the new note is written at the disambiguated path with action skipped-collision-resolved.

The generator marker value is session-orchestrator-vault-mirror@1 and appears in the YAML frontmatter as _generator: session-orchestrator-vault-mirror@1.

Auto-Commit Phase

After a successful mirror pass, scripts/lib/vault-mirror/auto-commit.mjs (autoCommitVaultMirror(vaultDirPath, sessionId, repo)) optionally commits the freshly-written mirror artifacts in 40-learnings/ and 50-sessions/ as a single chore(vault): mirror … commit. It runs unattended at session-end Phase 3.7 / evolve Phase 3.5. The phase is fail-safe: it never throws, emits one JSON action line on stdout, and aborts (unstaging everything) if any staged path is not a generator-stamped mirror artifact. When the optional repo namespace is passed (#660), staging is scoped to 40-learnings/<repo> + 50-sessions/<repo> and the phase additionally aborts with reason cross-repo-staged-changes if any staged file belongs to a different repo's namespace — so one project's mirror run can never commit another project's notes. Omitting repo preserves the legacy whole-directory behaviour.

Pre-commit hook bypass (--no-verify)

The auto-commit deliberately commits with --no-verify, skipping the vault repo's pre-commit hooks. This bypass is intentional (issue #603), not gratuitous, for two reasons:

1. Redundant validation. Before committing, the phase runs isMirrorArtifact() on every staged path — a per-file frontmatter check for the _generator: session-orchestrator-vault-mirror@1 marker. Any staged file lacking the marker triggers a full unstage and an auto-commit-skipped no-op. The committed files were written by vault-mirror's own generator, which already enforces conformant frontmatter (and the quality gate). The vault's pre-commit frontmatter / wiki-link validator would only re-check what is already guaranteed.
2. Must not block an unattended close. This is a machine auto-commit during session-end. An interactive, slow, or failing vault-side hook would stall the close. Bypassing it keeps session-end non-blocking.

Per .claude/rules/development.md Git Safety Protocol — "Never skip hooks (--no-verify) unless the user has explicitly asked for it" — the bypass is permissible here because it is explicit, documented, and committing already-validated content. A regression test in tests/lib/vault-mirror/auto-commit.test.mjs pins --no-verify into the commit git-args so a future silent removal is caught. If the vault's pre-commit hooks ever need to run on these commits, remove --no-verify together with this note and the test.

Failure Modes

Condition	Behaviour
Entry missing a required field	skipped-invalid emitted on stdout, error written to stderr, exit 0 (processing continues for remaining entries).
Malformed JSON on a JSONL line	Error written to stderr, exit 1 (processing stops).
--vault-dir not found	Error written to stderr, exit 2.
--source file not found	Error written to stderr, exit 2.
Hand-written file at target path	skipped-handwritten emitted on stdout, note written to stderr, file left unchanged.
Unknown _generator value in existing file	Treated as hand-written: skipped-handwritten, file left unchanged.
Unexpected filesystem write error	Error written to stderr, exit 2.

Examples

Mirror the sessions.jsonl for the current project into a vault:

node scripts/vault-mirror.mjs \
  --vault-dir ~/Projects/vault \
  --source .orchestrator/metrics/sessions.jsonl \
  --kind session

Dry-run a learnings mirror to preview actions without writing:

node scripts/vault-mirror.mjs \
  --vault-dir ~/Projects/vault \
  --source .orchestrator/metrics/learnings.jsonl \
  --kind learning \
  --dry-run

Live State

Phase 1 shipped and actively running. As of 2026-05-09, the skill has produced:

• 847 learning notes under vault://40-learnings/ — each carries _generator: session-orchestrator-vault-mirror@1 in the YAML frontmatter.
• 466 session notes under vault://50-sessions/ — same generator stamp.

Both target directories were verified by direct ls | wc -l measurement against ~/Projects/vault/. The numeric-prefix layout (40-learnings/, 50-sessions/) confirmed correct per the Target Paths spec above.

Phase-2: Flat-Corpus Relocation (#700)

scripts/relocate-vault-corpus.mjs is a one-time operator utility that migrates the legacy flat vault corpus (40-learnings/*.md + 50-sessions/*.md at depth 1) into the per-repo namespace subdirectories introduced by #660. Running it is never required for vault-mirror to function — the mirror writes to <repo>/ subfolders since #660 automatically. Relocation is a clean-up step for vaults that accumulated notes before per-repo namespacing existed.

Classifier logic

The classifier (scripts/lib/vault-relocation-rules.mjs) reads each file's YAML frontmatter:

• Session notes (type: session): derives repo from repo: frontmatter → project/<slug> tag → (optional, --with-backfill only) backfill index → _unsorted fallback.
• Learning notes (type: learning): derives repo from project: wikilink → source: free-text field → source_session: wikilink (transitive: looks up the session's own namespace) → _unsorted fallback.

Every derived value routes through resolveRepoNamespace() (the same CP1/CP6/CP10 leak-guard used by vault-mirror) so private slugs redact to redacted-repo and no personal home path leaks into a namespace.

repo: backfill (--with-backfill, #700)

Most legacy session notes (~466 of 653 at last census) carry no repo: field, so they — and every learning that transitively points at them via source_session: — fall to _unsorted. --with-backfill infers the owning repo from an authoritative signal rather than a guess: the note's id: is joined against each sibling repo's own .orchestrator/metrics/sessions.jsonl session_id.

• HIGH — id found in exactly one repo's sessions.jsonl → that repo. (An id present in >1 repo is ambiguous → SKIP, never a guess.)
• MEDIUM — id not found, but the branch+date parsed from the id matches exactly one repo → that repo. (Colliding branch+date pairs → SKIP.)
• SKIP — no unambiguous signal → stays _unsorted (non-destructive).

The inference lives in the pure module scripts/lib/vault-repo-backfill.mjs (inferRepoForSession / buildBackfillIndex / isBackfillDerivable); the CLI builds the cross-repo sessions.jsonl index and threads it into both buildSessionRepoIndex (so backfilled sessions lift their transitive learnings) and the classify loop. Every inferred slug still passes through resolveRepoNamespace() — a mis-inferred private slug redacts to redacted-repo and is excluded from any confident move. Backfilled sessions feed --derivable-only exactly like repo:-carrying ones.

Non-derivable files (_unsorted, redacted-repo, unknown-repo) are moved to a _unsorted/ subfolder (or skipped entirely when --derivable-only is set).

Modes

Mode	Flag	What happens
Preview (default)	--dry-run	Read-only scan — reports would-move lines, writes nothing. Always run this first.
Apply	--apply	Executes git mv (stages only — no commit). Operator reviews diff and commits separately.
Confident-only apply	--apply --derivable-only	Like --apply but skips files with confident===false (_unsorted, redacted-repo, unknown-repo destinations).
Backfill (opt-in)	--with-backfill	Infer repo: for repo-less session notes via the authoritative id: → sibling-repo sessions.jsonl join (HIGH/MEDIUM/SKIP). Composes with any mode; without it, output is byte-identical to before.
Repos root	--repos-root <dir>	Parent dir holding the sibling repos whose sessions.jsonl the backfill scans (default: parent of --vault-dir; Archiv/dot-dirs excluded).
Rollback	--rollback <manifest>	Reverses a prior --apply run using the reverse-manifest written at <vault-dir>/.orchestrator/relocation-manifest-<ISO>.json.

Scope filters: --learnings-only / --sessions-only restrict to one corpus root.

Safety model

1. Dry-run is the default. --apply must be explicit; there is no accidental write path.
2. --vault-dir is required. No default prevents silently operating on a wrong directory.
3. Stage-only. --apply calls git mv (which stages) but never commits. The operator owns the commit.
4. Reverse-manifest. Every --apply run writes <vault-dir>/.orchestrator/relocation-manifest-<ISO>.json. Pass this path to --rollback to undo.
5. Structural idempotency. Files already at depth ≥ 2 (already namespaced) are never enumerated or moved.
6. Destination-collision guard. If the target path already exists, the file is skipped with reason: dest-exists — no data is ever overwritten.
7. Leak-guard guarantee. Every derived namespace value runs through resolveRepoNamespace() before use. Private slugs redact to redacted-repo; files that would land in redacted-repo/ are excluded by --derivable-only or left flat if the operator chooses.

Usage

# Step 1: Preview (dry-run default)
node scripts/relocate-vault-corpus.mjs --vault-dir ~/Projects/vault

# Step 2: Move only confident files (skip _unsorted/redacted-repo)
node scripts/relocate-vault-corpus.mjs --vault-dir ~/Projects/vault --apply --derivable-only

# Step 2b: Lift coverage further by backfilling repo: for repo-less sessions (preview first)
node scripts/relocate-vault-corpus.mjs --vault-dir ~/Projects/vault --with-backfill --derivable-only          # dry-run
node scripts/relocate-vault-corpus.mjs --vault-dir ~/Projects/vault --with-backfill --derivable-only --apply  # then apply

# Step 3 (optional): Roll back if something looks wrong
node scripts/relocate-vault-corpus.mjs --rollback ~/Projects/vault/.orchestrator/relocation-manifest-<ISO>.json

Exit codes: 0 success (including dry-run); 1 input/arg error; 2 IO error. Data goes to stdout; diagnostics and summary go to stderr. Add --json for JSONL output (one record per file).

N-root canonical guard (named vaults)

scripts/vault-mirror.mjs enforces that the --vault-dir target is a known vault (guard: git remote ends with a canonical vault suffix). Phase-2 generalises this from a single /agents/vault suffix to N named suffixes via scripts/lib/named-vault-resolver.mjs. When vaults: is declared in owner.yaml (see owner-persona.md), the guard uses .some() across all configured suffixes. When vaults: is absent, behaviour is byte-identical to the pre-#700 single-suffix path.

Configuration

vault-mirror respects the vault-integration block in the project's Session Config (CLAUDE.md, or AGENTS.md on Codex CLI). The script itself does not read Session Config — the calling skill (session-end, evolve) is responsible for reading the config and deciding whether to invoke vault-mirror at all.

Field	Type	Default	Meaning
vault-integration.enabled	boolean	false	When false, the calling skill skips vault-mirror entirely.
vault-integration.vault-dir	string	—	Absolute or ~-prefixed path to the Meta-Vault root. Passed as --vault-dir.
vault-integration.mode	strict, warn, or off	warn	When off, the calling skill skips vault-mirror. When warn, mirror failures are surfaced as warnings but do not block session close. When strict, mirror failures block session close.