## Thinking Path
> - Paperclip is the open source app people use to manage AI agents for
work
> - The Rust runner now owns validated, scoped ACPX reducer events and
safe session suspension
> - Durable PRP transport must receive provider-neutral events rather
than sidecar-native envelopes
> - Semantic calls and questions must retain the exact run, session,
turn, item, and provider-request authority used by the durable command
stream
> - Terminal, result, assistant, process, and diagnostic events also
need one reviewed projection boundary
> - Permission requests remain impossible under the pinned Codex policy
and must fail closed if they reach projection
> - This pull request adds only that package-local projection without
selecting ACPX in runnerd
## Linked Issues or Issue Description
Refs #12422
## What Changed
- Add a validated durable ACPX event projection context bound to one
run, normalized session, turn, and item.
- Pass already normalized activity events through without reintroducing
provider-native envelopes.
- Project authorized tool calls into canonical semantic input receipts
with exact correlation and content digests.
- Project structured questions into provider-neutral
`paperclip.runtime_request.v2` events.
- Preserve both the public projected request identity and the original
provider request identity so responses resolve the exact sidecar
request.
- Project dynamic semantic operation results as `semantic_tool.result`;
only reserved finish/block operations may propose the run result.
- Project semantic completion results into `run.result.proposed`.
- Project terminal-flushed assistant messages on the final channel and
turn terminal states into existing provider-neutral event families.
- Project sanitized process metadata and diagnostics into bounded
harness diagnostics.
- Validate runtime-request origins against their strict durable shape
and fall back from empty optional titles to a valid question prompt.
- Reject invalid identities, projected-identity collisions, unstable
semantic receipt identities, permission requests, and cross-turn
projection fail closed.
- Add integration coverage across reducer event families, correlation,
identity validation, projected question resolution, and pinned-policy
denial.
- Document the durable projection boundary.
- Do not change dependencies, lockfiles, workflows, runnerd selection,
server behavior, UI, or migrations.
## Verification
- Replay base: `80639f4f69c8938eb74bdc0833df93e0ed91dab3` (`master`
after #12422 merged).
- Exact replay head: `3cb29581d2bcbc4b47f8069baffd721c6ce4e444`.
- Stable patch ID: `92910b56575e67ae83960177d467a565019ba282`.
- The exact delta is 22 files, 1,206 additions, and 59 deletions, all in
`packages/paperclip-runner`; it contains no lockfile, workflow, server,
UI, dependency, or migration change.
- `git diff --check` and the Cargo formatting check pass on the replayed
delta.
- Exact-head GitHub Actions run `33372209037` (attempt 2): **PASSED**
with 23/23 jobs passed.
- Greptile reviewed exact head
`3cb29581d2bcbc4b47f8069baffd721c6ce4e444`: **5/5**, with zero
unresolved review threads.
- Superagent, contributor trust, Socket, and Snyk security checks:
**PASSED**.
- No local test result is claimed. GitHub Actions is the authoritative
verification environment for this replayed revision.
## Risks
- This function accepts reducer output, not raw sidecar frames. Callers
must preserve the existing scope-first decode and reduction order.
- Semantic input includes the already sanitized provider input while its
content receipt uses the same canonical digest.
- Structured input preserves the validated provider-neutral question set
and sanitized origin.
- Noncanonical provider request identities are deterministically
projected for PRP while the original identity remains authoritative for
the sidecar resolution command.
- Existing PRP v1 identifiers remain schema-compatible; the only public
ID-schema change widens turn/item limits from 160 to 240 characters. The
internal ACPX sidecar wire schema now mirrors the stable IDs its Rust
transport already enforced.
- The projector verifies event-carried terminal and assistant turn
identifiers against the durable context.
- No production path invokes this projector in this pull request.
Durable command execution remains the next slice.
> For core feature work, check [`ROADMAP.md`](ROADMAP.md) first and
discuss it in `#dev` before opening the PR. Feature PRs that overlap
with planned core work may need to be redirected — check the roadmap
first. See `CONTRIBUTING.md`.
## Model Used
- OpenAI Codex with GPT-5.6, agentic reasoning, tool use, and 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 linked the preceding public PR or described the issue in-PR
- [x] I have not referenced internal or instance-local Paperclip issues
or links
- [x] My branch name describes the change and contains no internal
Paperclip ticket id
- [ ] I have run tests locally and they pass
- [x] 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
## Thinking Path
> - Paperclip is the open source app people use to manage AI agents for
work.
> - Paperclip Runner needs a language-neutral contract between the
server and the runner process.
> - A shared contract must exist before TypeScript, Rust, transport, or
provider implementations can depend on it.
> - Required protocol versions must fail closed, while safe optional
fields must remain compatible.
> - The contract also needs deterministic fixtures and a drift gate for
later cross-language work.
> - This pull request adds that contract without adding runtime
behavior.
> - The benefit is a small, reviewable source of truth for the next
implementation pull requests.
## Linked Issues or Issue Description
**Subsystem affected**
Cross-cutting. This pull request adds a private package contract for
later server, TypeScript, and Rust work.
**Problem or motivation**
Paperclip Runner does not have a small language-neutral protocol
boundary on `master`. A runtime implementation without this boundary can
drift between languages, accept unsupported required versions, or
silently change canonical fixtures.
**Proposed solution**
Add PRP v1 JSON Schemas, accepted and rejected fixtures, a Codex
structured-question fixture, and a generated SHA-256 manifest. Run
compatibility and manifest checks during the package build. Keep the
package private and export nothing in this pull request.
**Alternatives considered**
The combined runner branch contains schemas together with providers,
SDKs, labs, and server behavior. That change is too large for normal
review. Generating TypeScript validators in this pull request would also
cross into the next review unit.
**Roadmap alignment**
This contract supports the governed tool and control-plane direction in
`ROADMAP.md`. It does not enable a new production adapter or endpoint.
**Additional context**
Refs #12084 and #11962. This pull request was reviewed as a stack on
#12084, then rebased and retargeted to `master` after #12084 merged. The
current delta is 38 files.
## What Changed
- Added 20 PRP v1 JSON Schemas with stable identifiers and resolved
references, including explicit cross-language conformance input and
output schemas.
- Added canonical replay, cross-language, and Codex question fixtures.
- Added accepted cases for additive optional fields and a rejected case
for an unsupported required protocol version.
- Added a deterministic manifest with SHA-256 digests for every schema
and fixture.
- Added package-local schema-instance, schema-reference, compatibility,
question-ID, conformance-pair, and drift checks.
- Added a private workspace package with no public exports and no
production runtime behavior.
- Added the package manifest to the Docker dependency-stage inventory
required for every workspace package. This does not copy or build runner
runtime code into the production image.
- Kept the provider descriptor and question fixture Codex-only. No
deferred provider package or dependency is present.
## Verification
- `pnpm install --frozen-lockfile` passed with Node 24.19.0 and pnpm
9.15.4. No lockfile change is committed.
- `pnpm --filter @paperclipai/paperclip-runner check:protocol` passed
with 8 tests.
- The committed AJV 2020-12 gate accepted every canonical v1 replay,
question, and cross-language conformance fixture. It rejected the
required v2 fixture, a replay fixture with a missing required command
ID, and conformance output with a missing session ID.
- `pnpm -r typecheck` passed.
- `pnpm build` passed and ran the protocol manifest drift check.
- `pnpm check:token-gates` passed.
- `node ./scripts/check-docker-deps-stage.mjs` passed.
- `git diff --check` passed.
- The delta against its declared base is 38 files.
- `pnpm test:run` completed with 4,687 passing tests, 19 skipped tests,
and 29 failures across 9 unchanged server files. The failures reproduce
macOS path aliases, local listener probes, workspace-runtime
assumptions, and one connection-retry timeout. No changed-file test
failed. Linux CI must pass before this pull request is ready.
- `pnpm check:tokens` reports existing personal-name references outside
this pull request. A scoped scan of `packages/paperclip-runner` found no
secret-like values, internal references, or deferred-provider names.
- PR #12084 was squash-merged, and this branch was rebased onto that
merge and retargeted to `master`. The first master-base policy run
correctly caught the missing Docker dependency-stage manifest copy;
commit `4fa1ea7c` fixes that gate, and the complete Linux matrix is
green.
- Serialized server shard 1 initially hit an unchanged heartbeat
test-harness timeout and a later assertion in the same file. Its
isolated rerun passed in 3m57s. All other shards passed on their first
attempt.
- Greptile reviewed the final commit at 5/5 with no blocking failure.
Both earlier actionable validation threads are resolved, and no review
thread remains open.
## Risks
Low production risk. The package is private and has no exports, server
adapter, endpoint, or process. AJV is a package-only development
dependency that the server workspace already uses. The main risk is
contract churn before the TypeScript and Rust consumers land. The
generated manifest and compatibility fixtures make that churn explicit.
I checked `ROADMAP.md`. This change defines a contract for planned
control-plane work and does not add overlapping product behavior.
## 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
- [x] 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
---------
Co-authored-by: Paperclip <noreply@paperclip.ing>
Dotta