Long agent loops re-send the brief prefix on every step; cheap reusable
knowledge (architecture summary, module map, conventions, glossary) belongs
in a versioned file the maintainers control so the agent doesn't re-derive
it from the source tree on every PR. Two wiring paths, merged (env first):
* env var PRAGENT_ADDITIONAL_CONTEXT_URL — comma-separated, deployment-wide
* .pr-review.json:additional_context_urls — list[str], read from the PR's
base branch (same trust boundary as the rest of the file)
Implementation:
* _parse_additional_context_env splits/dedupes/trims.
* _resolve_additional_context_urls(config) merges env (first) + config
(then, skipping env-dupes); caps at 8.
* fetch_additional_context(urls) fetches each URL with urllib (5s timeout,
http/https only — file://, javascript:, ftp:// rejected defensively),
caches by URL in a module-level dict for the pod lifetime, truncates
per-URL to 4k chars + total to 16k chars, best-effort (network errors
are logged and skipped — never aborts the review).
* Result injected into build_user_prompt under "## Repo-provided context"
between repo config and prior reviews. In the opencode engine it lands
in .pragent/brief.md under its own section. The brief explicitly labels
each block's CONTENT as untrusted (same as PR description) — section
heading is trustworthy, body isn't.
* parse_repo_config accepts the field, caps at 8 entries, drops
non-strings and empty strings.
Docs: pilot/README-webhook.md "Repo-provided static context" section —
env var + JSON example + Nexus raw-hosted recipe.
Tests: 14 new (208 total), covering env merging + dedup, scheme rejection,
per-URL cap, total cap, caching by URL, brief injection. All mock urllib
with a context-manager stand-in (no real network).
Co-Authored-By: Claude <noreply@anthropic.com>
Marcos
e8ebc54362