## Thinking Path
The same 2026-04-30 audit that produced PR #4118 (`Invalid session`
regex extension) and the ENOTFOUND classifier (#4931) identified a third
stuck-session pattern: **13 failures in 7 days, all on a single agent
(Ernest)**, with stderr matching:
```
_ApiError: {"error":{"code":400,"message":"The input token count exceeds
the maximum number of tokens allowed 1048576","status":"INVALID_ARGUMENT"}}
at ChatCompressionService.compress
```
The root cause is that gemini-cli's `ChatCompressionService` blew the 1M
token context limit **during its compression step itself**. Resuming the
same session ID will hit the same wall on the next attempt — the session
is effectively dead the same way it is when "Invalid session identifier"
fires (PR #4118).
## What Changed
Extends the `isGeminiUnknownSessionError` regex in `parse.ts` with two
phrases:
- `exceeds\s+the\s+maximum\s+number\s+of\s+tokens`
- `input\s+token\s+count\s+exceeds`
Both trigger the **existing** fresh-session retry path in
`execute.ts:596` — no new code path. Same extension pattern as PR #4118.
## Verification
- `npx vitest run --project @paperclipai/adapter-gemini-local` → 14/14
pass (11 in `parse.test.ts` + 3 existing in `execute.remote.test.ts`)
- 2 new tests cover the token-overflow patterns
- `pnpm --filter @paperclipai/adapter-gemini-local typecheck` → clean
- Audit query against `heartbeat_runs.stderr_excerpt` confirms regex
matches all 13 occurrences
## Stacking
This PR is stacked on top of #4931 (the ENOTFOUND classifier) which adds
the `parse.test.ts` file. If #4931 merges first, this PR's diff is just
the regex + 2 tests. If this PR is reviewed first, please merge #4931
first to avoid touching the same test scaffolding twice.
## Risks
- **Low.** Single-line regex extension. No new code paths.
- The session-reset path is well-trodden (PR #4118 in flight).
- If a non-Gemini caller produces a stderr containing "exceeds the
maximum number of tokens" by coincidence, they would trigger one
unnecessary fresh-session retry. Not plausible in the gemini-cli output
context where this stderr is sourced.
## Model Used
Claude Opus 4.7 (1M context), Anthropic SDK via Claude Code CLI.
## Checklist
- [x] Thinking path traces from audit data to single-line regex change
- [x] Model specified
- [x] No duplicate of planned core work
- [x] Tests pass locally
- [x] Tests added (2 new)
- [x] N/A — server-side regex
- [x] Internal pattern; no docs change
- [x] Risks documented
- [x] Will address Greptile + reviewer comments before merge
- [x] I searched the GitHub PR list for similar PRs and confirmed this
is not a duplicate (related: #4118 covers the "Invalid session
identifier" regex; this PR extends the same regex with token-overflow
phrases)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Devin Foley <devin@paperclip.ing>
Co-authored-by: Paperclip <noreply@paperclip.ing>
## Thinking Path
> - Paperclip orchestrates AI-agent companies through a control plane
that can start, supervise, and recover agent runs.
> - Local adapters are the bridge between Paperclip issues and concrete
agent runtimes such as Claude, Codex, and other ACP-compatible tools.
> - The roadmap calls out broader “bring your own agent” and claw-style
agent support, and ACPX gives Paperclip one path to normalize multiple
ACP agents behind a single adapter.
> - The branch needed to become one reviewable PR against current
`paperclipai/paperclip:master`, without carrying stale base conflicts or
generated lockfile churn.
> - This pull request adds an experimental built-in `acpx_local`
adapter, integrates it through the server/CLI/UI adapter surfaces, and
adds regression coverage for runtime execution, skill sync, stream
parsing, diagnostics, and log redaction.
> - The benefit is that Paperclip can run Claude/Codex/custom ACP agents
through ACPX while keeping operator configuration, skills, logging, and
transcript rendering inside the existing adapter model.
## What Changed
- Added `@paperclipai/adapter-acpx-local` with server execution, config
schema, ACPX session handling, CLI formatting, UI config helpers, and
stdout parsing.
- Registered `acpx_local` across CLI, server, shared constants, UI
adapter metadata, adapter capabilities, and agent creation/editing
surfaces.
- Added ACPX runtime execution support with persistent sessions,
local-agent JWT environment handling, skill snapshots, runtime skill
materialization, and isolation/security regressions.
- Added ACPX adapter diagnostics and marked the adapter experimental in
the UI.
- Added command/env secret redaction for resolved command metadata in
adapter-utils, server event storage, and the Agent Detail invocation UI.
- Added Storybook coverage for ACPX config, transcript rendering, and
skill states, plus PR screenshots under `docs/pr-screenshots/pap-2944/`.
- Rebased the branch onto current `public-gh/master`; `pnpm-lock.yaml`
is intentionally not included and there are no migration/schema changes.
## Verification
- `pnpm exec vitest run
packages/adapters/acpx-local/src/server/execute.test.ts
packages/adapters/acpx-local/src/server/test.test.ts
packages/adapters/acpx-local/src/cli/format-event.test.ts
packages/adapters/acpx-local/src/ui/parse-stdout.test.ts
packages/adapter-utils/src/server-utils.test.ts
server/src/__tests__/redaction.test.ts
server/src/__tests__/acpx-local-execute.test.ts
server/src/__tests__/acpx-local-skill-sync.test.ts
server/src/__tests__/acpx-local-adapter-environment.test.ts
server/src/__tests__/adapter-routes.test.ts
server/src/__tests__/agent-skills-routes.test.ts
ui/src/adapters/metadata.test.ts` — 12 files, 87 tests passed.
- `pnpm --filter @paperclipai/adapter-acpx-local typecheck` — passed.
- `pnpm --filter @paperclipai/server typecheck` — passed.
- `pnpm --filter @paperclipai/ui typecheck` — passed.
- Confirmed PR diff does not include `pnpm-lock.yaml`, database schema
files, or migrations.
Screenshots:



## Risks
- Medium risk: this introduces a new built-in adapter package and
touches runtime execution, adapter registration, agent config, skills,
and transcript rendering.
- ACPX and ACP agent behavior can vary by installed tool versions; the
adapter is marked experimental to set operator expectations.
- `pnpm-lock.yaml` is excluded per repository PR policy, so dependency
lock refresh must be handled by the repo’s automation or maintainers.
- No database migration risk: no schema or migration files changed.
> 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 coding agent based on GPT-5, with repository tool use,
shell execution, git operations, and local verification. Exact hosted
context window was not exposed in this environment.
## 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 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] I will address all Greptile and reviewer comments before
requesting merge
---------
Co-authored-by: Paperclip <noreply@paperclip.ing>
Rename all workspace packages from @paperclip/* to @paperclipai/* and
the CLI binary from `paperclip` to `paperclipai` in preparation for
npm publishing. Bump CLI version to 0.1.0 and add package metadata
(description, keywords, license, repository, files). Update all
imports, documentation, user-facing messages, and tests accordingly.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Introduce AdapterSessionCodec interface for structured session serialization,
deserialization, and display ID extraction. Implement codecs for claude_local
and codex_local adapters with cwd validation — sessions saved for a different
working directory are not resumed. Both adapters now return sessionParams and
sessionDisplayId alongside legacy sessionId.
Add isCodexUnknownSessionError detection and automatic retry with fresh session
for codex_local (matching existing claude_local behavior). Inject approval
context env vars (PAPERCLIP_APPROVAL_ID, PAPERCLIP_APPROVAL_STATUS,
PAPERCLIP_LINKED_ISSUE_IDS) into adapter environments.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>