## Thinking Path
> - Paperclip manages AI agents and their execution environments.
> - Managed Git helpers run next to those agents.
> - Some environments keep their Node interpreter outside the agent
PATH.
> - The current generator always emits an env-based Node shebang.
> - This pull request lets the environment select an absolute
interpreter path.
> - Existing callers keep the same default behavior.
## Linked Issues or Issue Description
Refs #18212.
**What happened?**
A managed helper can fail when Node exists only as a private runtime
binary. The caller must currently alter generated source or expose that
runtime through PATH.
**Expected behavior**
The source generator accepts an optional interpreter path. The
environment can keep its own runtime private.
**Steps to reproduce**
Generate a helper in an environment whose PATH has no usable Node. Run a
local Git command through that helper. The env-based shebang cannot
select the private interpreter.
## What Changed
- Add optional `interpreterPath` to `githubLauncherSource`.
- Preserve `/usr/bin/env node` when the option is absent.
- Reject relative paths, whitespace and NUL bytes.
- Document the option and test actual execution with an unusable Node on
PATH.
## Verification
- The affected adapter-utils package typecheck passed.
- All 26 tests in `packages/adapter-utils/src/github-launcher.test.ts`
passed.
- The new test runs a generated helper as a child process. It proves
that the selected interpreter bypasses a failing PATH-selected Node and
that the helper body stays unchanged.
- Invalid-path tests passed. Existing broker and local-Git tests passed.
- Full checks run in GitHub CI per the user's request. No full local
suite was run.
## Risks
The option changes only the shebang. Callers own interpreter
installation and immutability. Default behavior, PATH, credentials and
permission policy stay unchanged. No schema or workflow changes.
## Model Used
OpenAI GPT-6.1 Sol (`gpt-6.1-sol`), high reasoning, with source
inspection and targeted execution. The host does not expose an exact
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>
