## Thinking Path
> - Paperclip orchestrates AI agents for zero-human companies, so when
an adapter fails, the platform must surface enough detail for the next
agent (or human reviewer) to act
> - The `acpx_local` adapter wraps `claude-agent-acp`, which in turn
drives the Claude Code SDK — three layers, three different permission
and error-handling models
> - A user created a `Claude Local ACPX` agent in PAPA-387 and it failed
instantly with the generic `acpx.error / "Internal error"` log,
stranding the work and triggering an opaque `stranded_assigned_issue`
recovery to the CTO
> - Once the diagnostic blackbox was opened, the underlying cause turned
out to be two SDK-level mismatches: a model-name allowlist that rejects
bare IDs like `claude-opus-4-7`, and a Claude Code
permission/Read-sandbox configuration that silently denies every
non-allowlisted tool when the user's `~/.claude/settings.json` has
`defaultMode: "dontAsk"`
> - This pull request fixes both classes of failure in the adapter
itself so new ACPX agents work seamlessly without per-host
configuration, and widens the diagnostic surface so the *next* failure
of any kind is actionable
> - The benefit is that ACPX-Claude can join the regular agent roster —
verified end to end on PAPA-401, where the agent successfully reached
the Paperclip API, opened a worktree, surveyed existing notification
PRs, and posted a structured plan
## What Changed
- Widen ACPX failure diagnostics
(`packages/adapters/acpx-local/src/server/execute.ts`):
- Capture `err.name`, ACP code, `cause.message`, retryable flag, and a
5-frame stack preview into `errorMeta`.
- Promote phase-specific error codes: `ensure_session →
acpx_session_init_failed`, `configure_session →
acpx_session_config_failed`, `turn → acpx_turn_failed`, plus mapping for
`ACP_BACKEND_MISSING` / `ACP_BACKEND_UNAVAILABLE`.
- Set `verbose: true` on the ACPX runtime so its session-event log flows
through `ctx.onLog`.
- Capture child-process stderr via a wrapper-script tee into
`<stateDir>/run-stderr/<runId>.log`, inline the tail into the
`acpx.error` payload as `childStderrTail`, and forward it through
`ctx.onLog("stderr", …)` so it lands in the heartbeat `stderrExcerpt`
column (existing redaction applies).
- Set the model via `ANTHROPIC_MODEL` env for the `claude` agent instead
of `set_config_option(model, …)`. The ACP server's `set_config_option`
handler validates against an internal allowlist and rejects bare IDs
like `claude-opus-4-7`. `ANTHROPIC_MODEL` is read during initialization
and bypasses that check.
- Seed `<worktree>/.claude/settings.local.json` before spawning
`claude-agent-acp` (the seamless-API fix). Since `claude-agent-acp`
hard-codes `settingSources: ["user", "project", "local"]` and "local"
has the highest precedence:
- Set `permissions.defaultMode: "default"`, but **only** if the user's
value is missing or `"dontAsk"` (the broken case). Other modes like
`acceptEdits`/`plan` are preserved.
- Pre-allow Paperclip's Bash surface (`Bash(curl:*)`, `Bash(env:*)`,
`Bash(<cwd>/scripts/paperclip-issue-update.sh:*)`,
`Bash(<cwd>/scripts/paperclip:*)`).
- Widen `permissions.additionalDirectories` to include `stateDir`,
`agentHome`, and the per-company instance root
(`~/.paperclip/instances/<id>/companies/<companyId>`). Scoped to this
company only — does not expose other tenants.
- Existing user entries are merged, not replaced. The resolved roots are
folded into the session fingerprint so warm-session handles invalidate
when they change.
- Sync the existing server-side integration test
(`server/src/__tests__/acpx-local-execute.test.ts`) to assert
`acpx_session_init_failed` instead of the now-removed
`acpx_protocol_error` for `ACP_SESSION_INIT_FAILED` (a follow-up to
commit 1).
## Verification
- `pnpm --filter "@paperclipai/adapter-acpx-local" run typecheck` —
passes.
- `pnpm vitest run` in `packages/adapters/acpx-local` — 35/35 pass,
includes 4 new tests covering the settings.local.json write path (claude
only, merge with pre-existing content, `dontAsk` override, codex no-op).
- `pnpm vitest run src/__tests__/acpx-local-execute.test.ts` in
`server/` — 15/15 pass after the test-sync commit.
- End-to-end manual verification (PAPA-401): the `Claude Local ACPX`
agent that previously hit "restricted environment" now successfully
reaches the Paperclip API, opens its worktree, posts structured plan
comments, and flips the issue to `in_review` without any external
configuration.
## Risks
- **Low**, scoped to the `acpx_local` adapter. The settings.local.json
write is per-worktree (worktrees live under
`.paperclip/worktrees/<issue>/`) and only triggers when `acpxAgent ===
"claude"`. Existing user content is merged with `[...existing,
...paperclip]` and deduped — nothing is overwritten outright.
- The `defaultMode` override is intentionally narrow: it only flips
`"dontAsk"` (which silently denies every tool and is the root cause) to
`"default"`. Users who explicitly picked `acceptEdits`, `plan`, or any
other mode keep their choice.
- Stderr capture goes through the existing `log-redaction` pass before
persisting, so `PAPERCLIP_API_KEY` and similar secrets in the wrapper
env don't leak into heartbeat logs.
> 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
- Claude Opus 4.7 (`claude-opus-4-7`), running in the `claude_local`
adapter via Paperclip's harness. Extended thinking enabled, tool use
enabled.
## 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
- [ ] If this change affects the UI, I have included before/after
screenshots — N/A (adapter-only)
- [ ] I have updated relevant documentation to reflect my changes — no
user-facing docs changed; internal commentary in the code change
explains the SDK constraints
- [x] I have considered and documented any risks above
- [ ] I will address all Greptile and reviewer comments before
requesting merge
---------
Co-authored-by: Paperclip <noreply@paperclip.ing>
Devin Foley
96f0279e08