Context Inodes & Route Walking (M40)

Use this Skill when planning or reviewing work that touches module boundaries, when subagent context needs scoping to a module, or when the inode store is stale/missing.

Concepts

• Inode — .agent/inodes/<sha256>.json: structural metadata for one source file (exported interfaces, function signatures with param optionality, I/O types, declared complexity), content-addressed and decoupled from raw source. Inodes never contain file contents.
• Context tree — .agent/context/<domain>/<module>/node.json: derived from the source tree (never hand-authored). Each node carries a summary, child segments, and the inode refs for its subtree.
• Route walk — sequential segment-by-segment resolution (src/lib → load src/node.json, then src/lib/node.json). Walks return inode pointers; callers page in source explicitly only when needed.

Declared complexity convention

Complexity is declared, never inferred. Annotate with @complexity:

def process(records: list[dict]) -> list[dict]:
    """@complexity O(N)"""

/** @complexity O(N) */
export function validateForm(fields: InputProps[]): string[] { ... }

Commands

# Build/refresh the inode store + context tree (deterministic)
./scripts/build-context-inodes.sh [--repo-root PATH]

# Fail (exit 1) when indexed sources are stale
./scripts/build-context-inodes.sh --check

# Walk a context route (prints steps + in-scope inode refs)
./scripts/walk-context-route.sh --route orchestrator/review

# Via the launcher
./scripts/northstar context build --repo /path/to/repo
./scripts/northstar context walk --repo /path/to/repo --route src/lib

Gates and invariants

• doctor.sh fails closed when .agent/inodes/ exists but is stale (rebuild hint), and when committed Skill inodes are stale.
• The northstar review boundary gate skips with an explicit note when the inode store is absent or stale — it never reviews against untrusted metadata. See Skill code-reviewer for the boundary checks.
• Subagent manifests carry working_context (context root, inode refs, scope allow/deny) — see Skill capability-planning.