Awesome Reviewers

Treat every externally sourced value (API results, URLs, cached artifacts, filesystem-derived error strings, CLI/config inputs) as untrusted at the boundary, and apply context-specific hardening before it can be rendered, logged, persisted, or used in a subprocess.

Practical rules:

Example (Markdown-link hardening):

import re

_SAFE_MARKDOWN_LINK_SCHEMES = ("http://", "https://")
_MARKDOWN_LINK_UNSAFE_CHARS = ("(", ")", "[", "]", "\\")

def _sanitize_url_for_single_line_output(url: str) -> str:
    return re.sub(r"[\r\n]+", " ", url).strip()

def render_untrusted_url(url: str) -> str:
    if not url:
        return ""
    url = _sanitize_url_for_single_line_output(url)
    if not url.startswith(_SAFE_MARKDOWN_LINK_SCHEMES):
        return url  # inert plain text
    if any(ch in url for ch in _MARKDOWN_LINK_UNSAFE_CHARS):
        return url  # inert plain text
    return f"[{url}]({url})"  # safe HTTP(S) only

When implementing changes, add regression tests for: delimiter/active-syntax payloads, newline injection, path-leak checks, allowlist gating, and subprocess argument/host edge cases.