lineage: Skill for Claude Code

Lineage Package Security Guardrails

Lineage packages are portable local environments. A receiver should be able to inspect what a package will do before it changes their workspace.

Threat Model

Assume every package is untrusted until validated. A malicious or careless package may try to:

• include secrets or private local state;
• reference files outside the package;
• write outside the intended workspace;
• smuggle symlinks or path traversal entries;
• hide risky setup actions behind normal activation;
• make provider-specific assumptions look like core behavior.

Safety Rules

• Import and inspect must not execute setup actions.
• Setup and materialization must be explicit, reviewable, permission-gated, and idempotent.
• Never package API keys, auth tokens, .env values, credential stores, provider login state, shell history, or machine-local caches.
• Secret checks may report file paths and reasons, but not matched values.
• Prefer templates, schemas, sample CSVs, and placeholder config when private source data should not travel.
• Validate every package-controlled path before reading or writing. Absolute paths and .. traversal are unsafe unless a specific user-provided destination explicitly allows them.
• Reject or deliberately handle symlinks. Do not silently follow package symlinks into the receiver's machine.
• Keep capability declarations honest and human-readable. Do not imply enforcement exists until code actually enforces it.

Review Questions

• What exactly can the receiver inspect before enabling or running this package?
• What files will be created, modified, or deleted?
• Can the operation be declined without partial side effects?
• Can the same operation run twice without drift?
• Are source-user data and receiver-local config clearly separated?
• Is provider-specific behavior isolated behind an adapter?

Required Verification

Add tests for unsafe paths, secret-shaped inputs, repeated setup/materialization, and declined permission flows when those surfaces change.