feat: add support for GitHub Copilot API integration and enhance exec…

[notlikejuice]

… command handling

[Copilot]

Pull Request Overview

This PR introduces support for the GitHub Copilot API alongside enhanced process-execution handling and testing.

• Adds a GithubCopilotClient, configures it in the provider list, agent loop, and CLI login flow.
• Extends exec utilities and tests to include pid tracking, faster kill timeouts, zombie detection, and stronger assertions.

Reviewed Changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
tests/raw-exec-process-group.test.ts	Include pid in results, assert it’s >0, and improve ensureProcessGone with zombie detection and SIGKILL fallback
tests/invalid-command-handling.test.ts	Assert pid === 0 on spawn failure
tests/cancel-exec.test.ts	Assert pid > 0 on cancellation scenarios
src/utils/providers.ts	Register a new “githubcopilot” provider entry
src/utils/openai-client.ts	Implement GithubCopilotClient and branch it in createOpenAIClient
src/utils/get-api-key.tsx	Add getGithubCopilotApiKey() device-flow login with a spinner
src/utils/agent/sandbox/raw-exec.ts & interface.ts & exec.ts	Extend ExecResult with pid and wire it through all exec paths
src/utils/agent/agent-loop.ts	Integrate GithubCopilotClient instantiation in the agent loop
src/cli.tsx	Handle GitHub Copilot login flags and set corresponding env var

Comments suppressed due to low confidence (2)

codex-cli/src/utils/providers.ts:56

• [nitpick] The provider name uses inconsistent casing. Consider renaming to "GitHub Copilot" to match official branding and improve readability.

    name: "GithubCopilot",

codex-cli/src/utils/openai-client.ts:115

• Overriding authHeaders to return an empty object may strip necessary default headers (e.g., User-Agent). Ensure essential headers aren’t unintentionally dropped.

    return {};

[Copilot]

[nitpick] Extract this magic timeout value into a named constant or configuration so its purpose and trade-offs are clearer and reusable.

Suggested change

	const timeout = 1000;
	const deadline = Date.now() + timeout;
	const deadline = Date.now() + PROCESS_TERMINATION_TIMEOUT_MS;

[Copilot]

[nitpick] This GitHub OAuth client ID is hardcoded. Consider making it a configurable constant or retrieving it from environment or config to ease updates and testing.

[Copilot]

This block re-instantiates oai for GitHub Copilot after it was already created by createOpenAIClient, leading to duplicated logic and potential configuration drift.

[Copilot]

[nitpick] The login flow for GitHub Copilot is duplicated in multiple branches, making the CLI logic hard to follow. Consider consolidating into a single helper or clearer conditional structure.

Suggested change

	apiKey = await fetchGithubCopilotApiKey();
	try {
	const home = os.homedir();
	const authDir = path.join(home, ".codex");
	const authFile = path.join(authDir, "auth.json");
	fs.writeFileSync(
	authFile,
	JSON.stringify(
	{
	GITHUBCOPILOT_API_KEY: apiKey,
	},
	null,
	2,
	),
	"utf-8",
	);
	} catch {
	/* ignore */
	}
	} else if (cli.flags.login) {
	if (provider.toLowerCase() === "githubcopilot") {
	apiKey = await fetchGithubCopilotApiKey();
	apiKey = await handleGithubCopilotLogin();
	} else if (cli.flags.login) {
	if (provider.toLowerCase() === "githubcopilot") {
	apiKey = await handleGithubCopilotLogin();