## Thinking Path
> - Paperclip is the open source app people use to manage AI agents for
work.
> - Agent execution currently uses direct adapters inside the server
process.
> - The proposed Paperclip Runner adds a separate process and a new
protocol boundary.
> - This boundary needs clear trust, recovery, rollout, and
compatibility rules before code lands.
> - Large runner changes are difficult to review as one pull request.
> - This pull request defines the first small boundary for the runner
series.
> - The benefit is a stable design contract for later implementation
pull requests.
## Linked Issues or Issue Description
**Issue type**
Missing documentation.
**Where is the issue?**
The repository does not have a concise architecture decision or
compatibility contract for Paperclip Runner.
**What's wrong?**
The available runner design material is too large for normal review. It
mixes architecture, implementation history, test evidence, and deferred
work. Reviewers need a short statement of the process boundary, trust
model, rollout behavior, and direct-adapter compatibility rules.
**Suggested fix**
Add one architecture decision record and one compatibility document.
Keep implementation details and campaign evidence out of this pull
request.
Related public work: Refs #11041, #11297, #11634, #11639, #11640, and
#11962. This pull request is the first small replacement in the new
review series for #11962.
## What Changed
- Added an architecture decision for the runner process, PRP v1
transport, semantic tools, durable recovery, and additive server
integration.
- Added a compatibility and rollout contract for the default-off
adapter, existing direct adapters, persisted native runs, and the task
page.
- Defined the initial package and provider limits. The first production
provider is Codex only.
- Defined acceptance checks for later implementation pull requests.
## Verification
- `pnpm install --frozen-lockfile` passed with Node 24.19.0 and pnpm
9.15.4.
- `pnpm check:node-version` passed.
- `pnpm -r typecheck` passed.
- `pnpm build` passed.
- `git diff --check origin/master...HEAD` passed.
- The pull request changes 2 files.
- `pnpm test:run` completed with 4,686 passing tests and 30 failures in
unchanged master paths. The failures reproduce macOS path aliases,
invalid generated port values, and local listener behavior. This
documentation-only change does not touch those paths. Linux CI must pass
before this pull request is ready.
- All applicable GitHub Actions and security scans passed. The Storybook
visual job skipped because this documentation-only change does not match
its paths.
- Greptile completed at 5/5 with no actionable comments.
## Risks
Low implementation risk. This pull request changes documentation only. A
later implementation can still diverge from the contract. Each later
pull request must prove its behavior against these compatibility rules.
I checked `ROADMAP.md`. This design supports the governed tool and
control-plane direction. It does not add an overlapping user feature.
## Model Used
OpenAI Codex with GPT-5 was used. The exact serving model ID and context
size were not exposed. The model used high reasoning, repository tools,
GitHub tools, and local code execution.
## 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] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [ ] I have run tests locally and they pass
- [ ] I have added or updated tests where applicable
- [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
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