fix(wrap): set xAI upstream for grok-build proxy (#2772)

## Description

`headroom wrap grok-build` injected the client hop into
`~/.grok/config.toml` but started the local proxy **without** setting
the OpenAI-compatible upstream to xAI. The proxy defaulted to
`api.openai.com`, so Grok session auth returned **401** on every chat
completion even though compression still ran.

`wrap grok` already passes `openai_api_url` → xAI. This PR aligns `wrap
grok-build` and the Grok-only persistent `install` path on the shared
`DEFAULT_API_URL` (`https://api.x.ai`).

Closes # (none — discovered in live Grok Build pilot)

## Type of Change

- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
- [ ] Performance improvement
- [ ] Code refactoring (no functional changes)

## Changes Made

- Pass `openai_api_url=_GROK_DEFAULT_API_URL` into
`_run_proxy_only_watcher` from `wrap grok-build`
- Use shared `DEFAULT_API_URL` from `wrap grok` (no hard-coded string
drift)
- Print proxy upstream in Grok Build setup lines
- Persistent install: when targets are Grok-only, set
`OPENAI_TARGET_API_URL` + `--openai-api-url` (skip when
Codex/Copilot/Aider/OpenCode share the proxy; explicit env still wins)
- Regression tests for wrap kwargs, setup lines, and install planner

## Testing

- [x] Unit tests pass (`pytest` targeted suite)
- [ ] Linting passes (`ruff check .`) — not run in this environment (no
native editable build)
- [ ] Type checking passes (`mypy headroom`) — not run
- [x] New tests added for new functionality
- [x] Manual testing performed

### Test Output

```text
$ PYTHONPATH=$PWD python -m pytest \
    tests/test_cli/test_wrap_bridge.py::test_wrap_grok_build_passes_xai_openai_api_url \
    tests/test_cli/test_wrap_bridge.py::test_wrap_grok_build_uses_actual_proxy_port \
    tests/test_install/test_planner.py::test_build_manifest_grok_build_only_sets_xai_upstream \
    tests/test_install/test_planner.py::test_build_manifest_grok_with_codex_does_not_force_xai \
    tests/test_install/test_planner.py::test_build_manifest_extra_env_wins_over_grok_xai_default \
    tests/test_provider_grok_build.py::test_grok_build_setup_lines_include_proxy_url -q
......
6 passed in 0.33s
```

## Real Behavior Proof

- Environment: macOS (darwin), Headroom 0.33.0 via `uv tool install
"headroom-ai[proxy,mcp,code]==0.33.0"`, Grok Build CLI, models
`grok-build` and `grok-4.5`, proxy on `127.0.0.1:8787`, upstream must be
xAI
- Exact command / steps: (1) Before: stock `headroom wrap grok-build`
then `grok -m grok-build` one-shot prompt. (2) After: same wrap path
with this branch (`openai_api_url=DEFAULT_API_URL` into
`_run_proxy_only_watcher`) then `grok -m grok-build -p
'…HEADROOM_XAI_OK…'`. Also exercised `grok-4.5` via `[model."grok-4.5"]
base_url` → same proxy.
- Observed result: Before — proxy log outbound `api.openai.com` → HTTP
401; client failed while local compression still ran. After — setup line
prints Proxy upstream `https://api.x.ai`; proxy log `POST
https://api.x.ai/v1/chat/completions` (and `/v1/responses` for grok-4.5)
→ status=200; dashboard shows 0 failed requests and accumulating token
savings on live traffic.
- Not tested: full `uv run` editable/maturin native build on this host;
multi-tool install matrix beyond planner unit tests; Windows; ruff/mypy
full tree

## Review Readiness

- [x] I have performed a self-review
- [x] This PR is ready for human review

## Checklist

- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [x] I commented my code, particularly in hard-to-understand areas
- [ ] I made corresponding changes to the documentation (CLI help text /
setup lines only)
- [x] My changes generate no new warnings
- [x] I added tests that prove my fix is effective or that my feature
works
- [x] New and existing unit tests pass locally with my changes
- [x] I did **not** edit `CHANGELOG.md` — generated by release-please
from Conventional Commit PR title (a CI guard enforces this)

## Additional Notes

- Intentional non-goal: changing default model, savings %, or Grok Build
context-tool defaults
- Mixed-target install (e.g. `grok_build` + `codex`) does **not** force
xAI — operator must set upstream explicitly if they share one proxy
- Related live routing: manual `[model."grok-4.5"] base_url` through the
same proxy works once upstream is xAI (`/v1/responses`)

---------

Co-authored-by: Grok 4.5 <noreply@x.ai>
Co-authored-by: Nestor G Pestelos Jr <ngpestelos@me.com>
Co-authored-by: JD Davis <jd@jds-macbook-air.tail2a279.ts.net>

headroom/cli/wrap.py

@@ -136,7 +136,12 @@ from headroom.providers.copilot import (
     validate_configuration as _validate_copilot_configuration,
 )
 from headroom.providers.cursor import render_setup_lines as _render_cursor_setup_lines
-from headroom.providers.grok import build_launch_env as _build_grok_launch_env
+from headroom.providers.grok import (
+    DEFAULT_API_URL as _GROK_DEFAULT_API_URL,
+)
+from headroom.providers.grok import (
+    build_launch_env as _build_grok_launch_env,
+)
 from headroom.providers.grok_build import render_setup_lines as _render_grok_build_setup_lines
 from headroom.providers.grok_build.config import (
     inject_grok_provider_config,
@@ -6417,7 +6422,7 @@ def grok(
         backend=backend,
         anyllm_provider=anyllm_provider,
         region=region,
-        openai_api_url="https://api.x.ai",
+        openai_api_url=_GROK_DEFAULT_API_URL,
     )
 
 
@@ -6507,9 +6512,9 @@ def grok_build(
 
     \b
     Grok Build reads model endpoints from ``~/.grok/config.toml``. This
-    command starts the proxy, optionally sets up the selected CLI context
-    tool, injects a Headroom-managed ``[model.grok-build]`` override, and
-    prints next steps.
+    command starts the proxy (upstream ``https://api.x.ai``, same as
+    ``wrap grok``), injects a Headroom-managed ``[model.grok-build]``
+    override, and prints next steps.
 
     \b
     Example:
@@ -6536,6 +6541,8 @@ def grok_build(
         for line in _render_grok_build_setup_lines(actual_port, project=project):
             click.echo(line)
 
+    # Client hop is local proxy via config.toml; upstream must be xAI (not
+    # the OpenAI default). Omitting this caused 401s with Grok auth headers.
     _run_proxy_only_watcher(
         agent_label="grok-build",
         port=port,
@@ -6544,6 +6551,7 @@ def grok_build(
         memory=memory,
         agent_type="grok_build",
         print_setup_lines=_print_grok_build_setup,
+        openai_api_url=_GROK_DEFAULT_API_URL,
     )
 
 

headroom/install/planner.py

@@ -9,6 +9,7 @@ from collections.abc import Iterable
 import click
 
 from headroom import paths as _paths
+from headroom.providers.grok.runtime import DEFAULT_API_URL as _GROK_DEFAULT_API_URL
 from headroom.providers.install_registry import build_install_target_envs
 from headroom.rollout import RolloutChannel
 
@@ -177,6 +178,19 @@ def build_manifest(
     base_env["HEADROOM_TELEMETRY"] = "on" if telemetry_enabled else "off"
     if memory_enabled:
         base_env["HEADROOM_MEMORY_ENABLED"] = "1"
+    # Grok / Grok Build need proxy upstream = xAI. Only auto-set when no other
+    # OpenAI-compatible tools share this proxy (those may need api.openai.com /
+    # Copilot). Explicit OPENAI_TARGET_API_URL in extra_env still wins below.
+    _openai_native = {
+        ToolTarget.CODEX.value,
+        ToolTarget.COPILOT.value,
+        ToolTarget.AIDER.value,
+        ToolTarget.OPENCODE.value,
+    }
+    _grok_targets = {ToolTarget.GROK.value, ToolTarget.GROK_BUILD.value}
+    target_set = set(resolved_targets)
+    if target_set & _grok_targets and not (target_set & _openai_native):
+        base_env.setdefault("OPENAI_TARGET_API_URL", _GROK_DEFAULT_API_URL)
     # Applied last so explicit --env overrides win over the auto-derived
     # defaults above (e.g. a custom HEADROOM_WORKSPACE_DIR).
     if extra_env:
@@ -241,6 +255,9 @@ def build_manifest(
         proxy_args.extend(["--protect-tool-results", protect_tool_results])
     if bedrock_profile:
         proxy_args.extend(["--bedrock-profile", bedrock_profile])
+    openai_target = base_env.get("OPENAI_TARGET_API_URL")
+    if openai_target:
+        proxy_args.extend(["--openai-api-url", openai_target])
 
     container_name = f"headroom-{normalized_profile}"
     return DeploymentManifest(

headroom/providers/grok_build/runtime.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 from dataclasses import dataclass
 
+from headroom.providers.grok.runtime import DEFAULT_API_URL
 from headroom.proxy.project_context import with_project_prefix
 
 
@@ -41,6 +42,8 @@ def render_setup_lines(port: int, project: str | None = None) -> list[str]:
         "    [model.grok-build]",
         f'    base_url = "{target.base_url}"',
         "",
+        f"  Proxy upstream (OpenAI-compatible): {DEFAULT_API_URL}",
+        "",
         "  Start Grok Build in this project directory:",
         "    grok",
         "",

tests/test_cli/test_wrap_bridge.py

@@ -74,6 +74,40 @@ def test_wrap_grok_build_uses_actual_proxy_port(monkeypatch, tmp_path: Path) ->
     assert "http://127.0.0.1:8787/" not in result.output
 
 
+def test_wrap_grok_build_passes_xai_openai_api_url(monkeypatch, tmp_path: Path) -> None:
+    """Grok Build must set proxy upstream to xAI (same as wrap grok).
+
+    Without openai_api_url, the proxy defaults to api.openai.com and Grok
+    session auth returns 401 on every chat completion.
+    """
+    from headroom.providers.grok import DEFAULT_API_URL
+
+    _set_test_home(monkeypatch, tmp_path)
+    runner = CliRunner()
+    captured: dict = {}
+
+    def fake_watcher(**kwargs) -> None:
+        captured.update(kwargs)
+        kwargs["print_setup_lines"](kwargs["port"])
+
+    monkeypatch.setattr("headroom.cli.wrap._run_proxy_only_watcher", fake_watcher)
+
+    result = runner.invoke(main, ["wrap", "grok-build", "--port", "8787"])
+
+    assert result.exit_code == 0, result.output
+    assert captured.get("openai_api_url") == DEFAULT_API_URL
+    # Equality on the constant (not substring containment) keeps CodeQL
+    # incomplete-url-substring-sanitization quiet while pinning the host.
+    assert DEFAULT_API_URL == "https://api.x.ai"
+    expected_upstream = f"  Proxy upstream (OpenAI-compatible): {DEFAULT_API_URL}"
+    upstream_lines = [
+        line
+        for line in result.output.splitlines()
+        if line.startswith("  Proxy upstream (OpenAI-compatible): ")
+    ]
+    assert upstream_lines == [expected_upstream]
+
+
 def test_wrap_rejects_retired_context_tool_flag(monkeypatch, tmp_path: Path) -> None:
     """A surviving --context-tool must fail loudly, not be silently ignored.
 

tests/test_install/test_planner.py

@@ -330,3 +330,38 @@ def test_build_manifest_extra_env_overrides_derived_defaults() -> None:
     # telemetry_enabled=False in _base_manifest_kwargs would normally set "off";
     # an explicit --env must win.
     assert manifest.base_env["HEADROOM_TELEMETRY"] == "on"
+
+
+def test_build_manifest_grok_build_only_sets_xai_upstream() -> None:
+    """Persistent install for Grok Build alone must route proxy upstream to xAI."""
+    from headroom.providers.grok import DEFAULT_API_URL
+
+    manifest = build_manifest(**_base_manifest_kwargs(targets=["grok_build"], backend="openai"))
+
+    assert manifest.base_env.get("OPENAI_TARGET_API_URL") == DEFAULT_API_URL
+    idx = manifest.proxy_args.index("--openai-api-url")
+    assert manifest.proxy_args[idx + 1] == DEFAULT_API_URL
+
+
+def test_build_manifest_grok_with_codex_does_not_force_xai() -> None:
+    """Do not override OpenAI upstream when OpenAI-native tools share the proxy."""
+    manifest = build_manifest(
+        **_base_manifest_kwargs(targets=["grok_build", "codex"], backend="openai")
+    )
+
+    assert "OPENAI_TARGET_API_URL" not in manifest.base_env
+    assert "--openai-api-url" not in manifest.proxy_args
+
+
+def test_build_manifest_extra_env_wins_over_grok_xai_default() -> None:
+    manifest = build_manifest(
+        **_base_manifest_kwargs(
+            targets=["grok_build"],
+            backend="openai",
+            extra_env={"OPENAI_TARGET_API_URL": "https://gateway.example/v1"},
+        )
+    )
+
+    assert manifest.base_env["OPENAI_TARGET_API_URL"] == "https://gateway.example/v1"
+    idx = manifest.proxy_args.index("--openai-api-url")
+    assert manifest.proxy_args[idx + 1] == "https://gateway.example/v1"

tests/test_provider_grok_build.py

@@ -5,6 +5,7 @@ from pathlib import Path
 
 import pytest
 
+from headroom.providers.grok import DEFAULT_API_URL
 from headroom.providers.grok_build import build_proxy_targets, render_setup_lines
 from headroom.providers.grok_build.config import (
     inject_grok_provider_config,
@@ -46,6 +47,13 @@ def test_grok_build_setup_lines_include_proxy_url() -> None:
 
     assert "http://127.0.0.1:8787/v1" in joined
     assert "[model.grok-build]" in joined
+    # Exact labeled line equality (not bare host substring containment) so
+    # CodeQL does not flag incomplete URL substring sanitization.
+    expected_upstream = f"  Proxy upstream (OpenAI-compatible): {DEFAULT_API_URL}"
+    upstream_lines = [
+        line for line in lines if line.startswith("  Proxy upstream (OpenAI-compatible): ")
+    ]
+    assert upstream_lines == [expected_upstream]
 
 
 def test_grok_build_build_install_env_returns_proxy_url() -> None: