## Thinking Path > - Paperclip is the open source app people use to manage AI agents for work. > - The adapter layer carries sandbox requests to host processes. > - The HTTP/2 bridge used one process-wide byte ledger for all routes. > - One busy route could exhaust that shared budget and move another route to file transport. > - This pull request gives each host retention site a fixed byte bound and limits concurrent HTTP/2 streams. > - The benefit is local protection: one route cannot consume the byte budget of another route. ## Linked Issues or Issue Description **What happened?** The HTTP/2 bridge used one aggregate byte ledger for retained bytes across all routes. A busy route could exhaust the shared budget and force an unrelated route to use file transport. **Expected behavior** Each route should protect its own retained bytes. A reset on one HTTP/2 stream should cancel only that stream's host forward. **Steps to reproduce** 1. Start the HTTP/2 bridge with multiple sandbox routes. 2. Send enough retained data through one route to reach the aggregate byte limit. 3. Send a request through a sibling route. 4. Observe that the sibling route can fall back to file transport because the first route used the shared ledger. **Paperclip version or commit** `47639e227e78e3c5e0dd1a3c0e2d792fe86895a3` **Deployment mode** Built from source with the adapter-utils and server test suites. ## What Changed - Bound each host retention site with a fixed local byte limit. - Limited concurrent live HTTP/2 streams with one built-in stream limit. - Bound each host forward and response-body read to its own HTTP/2 stream lifetime. - Removed the process-wide byte ledger, its environment override, its metrics, and its file-transport fallbacks. - Added tests for the stream limit, host body budget, and sibling-stream cancellation. ## Verification - Run `pnpm vitest run --project adapter-utils`. - Confirm that 996 adapter-utils tests pass. - Confirm that `test_live_forward_work_never_passes_the_stream_limit` passes. - Confirm that `test_the_host_body_budget_matches_the_stream_limit` passes. - Confirm that the sibling-stream cancellation test passes. - Run `pnpm tsc --noEmit`. - Confirm that all pull request checks pass. ## Risks The bridge no longer uses a process-wide byte ledger. A local bound or stream limit that is too low can reject or delay valid work. The tests cover the new limits and stream cancellation behavior. ## Model Used OpenAI GPT-5 Codex. Runtime model ID: GPT-5. The model used code execution and repository tools. The runtime does not expose the context window size. ## 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 - [x] 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>
@paperclipai/adapter-utils
Shared utilities for Paperclip adapters: process spawning, environment injection, sandbox/SSH transport, workspace sync, and the round-trip helpers that move code between the local execution-workspace cwd and wherever the agent actually runs.
For the adapter-author guide see
docs/adapters/creating-an-adapter.md
and the in-repo notes at packages/adapters/AUTHORING.md.
No-remote-git contract
The local execution-workspace cwd is the only persistence boundary across runs. No adapter may depend on a git remote for cross-run state.
Adapters that run the agent on a different host should use the SSH round-trip
helpers in src/ssh.ts:
prepareWorkspaceForSshExecution({ spec, localDir, remoteDir })— bundles the local cwd (tracked files, dirty edits, untracked additions, and the git history needed to reconstruct it) toremoteDirbefore the run starts. Runs with nogit remoteconfigured.restoreWorkspaceFromSshExecution({ spec, localDir, remoteDir, ... })— syncs the remote cwd back intolocalDirafter the run, including any new commits the agent created. Also runs with nogit remoteconfigured.
prepareRemoteManagedRuntime in
src/remote-managed-runtime.ts wraps both
calls for adapters that want a per-run remote workspace and an automatic
restoreWorkspace() finally hook.
The invariant is pinned by the no-remote-git contract case in
src/ssh-fixture.test.ts, which asserts that a
remote-only commit propagates to the local worktree through the
prepare → restore round-trip with no git remote configured at any point. Do
not regress that test.