## Thinking Path
> - Paperclip is the open source app people use to manage AI agents for
work.
> - Agents coordinate through issue threads, so issue comments and
interactions are part of the task authorization surface.
> - Low-trust and boundary-limited agents can receive narrow
mention-scoped access, but that must not turn into broad same-company
issue-thread reads.
> - The comment creation path was narrowed to allow explicit mention
replies without granting mutation access.
> - The surrounding list/read routes still needed to enforce the same
`issue:read` boundary before returning thread data.
> - This pull request applies the issue read check to issue comment and
interaction listing routes, and locks that behavior with server
regressions.
> - The benefit is that narrow cross-agent collaboration remains
possible without exposing unrelated issue-thread history.
## Linked Issues or Issue Description
Bug fix:
- What happened: same-company agents outside an issue read boundary
could still hit issue-thread listing routes and receive thread data.
- Expected behavior: issue comments and issue-thread interactions should
only be listed after the actor is allowed to read the issue.
- Steps to reproduce: configure a peer agent denied by the issue read
boundary, then request `GET /api/issues/:id/comments` or the issue
interaction listing route.
- Paperclip version/commit: current `master` before this branch.
- Deployment mode: applies to server authorization in all modes.
Related public context: #7389, #7863, #8024.
## What Changed
- Added issue read enforcement before listing issue comments.
- Added issue read enforcement before listing issue-thread interactions.
- Added server regressions for denied peer-agent issue-thread access
while preserving mention-scoped collaboration behavior.
- Removed an avoidable per-mentioned-comment issue reload in
mention-grant authorization by passing the already-loaded issue assignee
through the helper.
- Documented cross-agent issue read/comment authorization behavior in
the Paperclip API reference.
- Added a resilient fallback for pinned external skills when GitHub tree
fetches are temporarily unavailable during catalog builds.
## Verification
- `pnpm vitest run
server/src/__tests__/issue-agent-mutation-ownership-routes.test.ts
server/src/__tests__/authorization-service.test.ts`
- 2 test files passed
- 84 tests passed
- Existing mocked recovery revalidation warnings were emitted by the
route suite and the command exited 0
- Greptile: 5/5 on commit `b73fc323f192dc44f88374c16865008d4348923b`; no
unresolved review threads.
- `pnpm vitest run packages/skills-catalog/src/catalog-builder.test.ts`
- 1 test file passed
- 6 tests passed
- CI: all visible PR checks are terminal green on commit
`b73fc323f192dc44f88374c16865008d4348923b`.
## Risks
Low risk. This tightens read authorization on issue-thread listing
routes; any caller that depended on same-company access without
`issue:read` will now receive 403 and must use an explicit grant or
valid issue read path.
## Model Used
OpenAI GPT-5 Codex, Codex coding agent environment, tool use and local
command execution enabled, reasoning mode active. Context window not
exposed by the runtime.
## Checklist
- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] If this change affects the UI, I have included before/after
screenshots
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge
---------
Co-authored-by: Paperclip <noreply@paperclip.ing>
Nicky Leach
364f0f5a8d