diff --git a/packages/adapters/codex-local/src/server/execute.test.ts b/packages/adapters/codex-local/src/server/execute.test.ts
new file mode 100644
index 00000000000..73b692b217b
--- /dev/null
+++ b/packages/adapters/codex-local/src/server/execute.test.ts
@@ -0,0 +1,109 @@
+import { mkdir, mkdtemp, rm, writeFile } from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+const {
+  runAdapterExecutionTargetProcess,
+  ensureAdapterExecutionTargetCommandResolvable,
+  ensureAdapterExecutionTargetRuntimeCommandInstalled,
+  resolveAdapterExecutionTargetCommandForLogs,
+} = vi.hoisted(() => ({
+  runAdapterExecutionTargetProcess: vi.fn(async () => ({
+    exitCode: 0,
+    signal: null,
+    timedOut: false,
+    stdout: "",
+    stderr: "",
+    pid: 123,
+    startedAt: new Date().toISOString(),
+  })),
+  ensureAdapterExecutionTargetCommandResolvable: vi.fn(async () => undefined),
+  ensureAdapterExecutionTargetRuntimeCommandInstalled: vi.fn(async () => undefined),
+  resolveAdapterExecutionTargetCommandForLogs: vi.fn(async () => "/usr/bin/codex"),
+}));
+
+vi.mock("@paperclipai/adapter-utils/execution-target", async () => {
+  const actual = await vi.importActual<typeof import("@paperclipai/adapter-utils/execution-target")>(
+    "@paperclipai/adapter-utils/execution-target",
+  );
+  return {
+    ...actual,
+    runAdapterExecutionTargetProcess,
+    ensureAdapterExecutionTargetCommandResolvable,
+    ensureAdapterExecutionTargetRuntimeCommandInstalled,
+    resolveAdapterExecutionTargetCommandForLogs,
+  };
+});
+
+import { execute } from "./execute.js";
+
+describe("codex execution billing attribution", () => {
+  const cleanupDirs: string[] = [];
+  const originalOpenRouterApiKey = process.env.OPENROUTER_API_KEY;
+
+  afterEach(async () => {
+    vi.clearAllMocks();
+    if (originalOpenRouterApiKey == null) {
+      delete process.env.OPENROUTER_API_KEY;
+    } else {
+      process.env.OPENROUTER_API_KEY = originalOpenRouterApiKey;
+    }
+    while (cleanupDirs.length > 0) {
+      const dir = cleanupDirs.pop();
+      if (!dir) continue;
+      await rm(dir, { recursive: true, force: true }).catch(() => undefined);
+    }
+  });
+
+  it("attributes direct OpenAI API runs to OpenAI despite an ambient host OpenRouter key", async () => {
+    process.env.OPENROUTER_API_KEY = "sk-or-host-ambient";
+    const rootDir = await mkdtemp(path.join(os.tmpdir(), "paperclip-codex-billing-"));
+    cleanupDirs.push(rootDir);
+    const workspaceDir = path.join(rootDir, "workspace");
+    const codexHomeDir = path.join(rootDir, "codex-home");
+    await mkdir(workspaceDir, { recursive: true });
+    await mkdir(codexHomeDir, { recursive: true });
+    await writeFile(path.join(codexHomeDir, "auth.json"), "{}", "utf8");
+
+    const result = await execute({
+      runId: "run-direct-openai",
+      agent: {
+        id: "agent-1",
+        companyId: "company-1",
+        name: "CodexCoder",
+        adapterType: "codex_local",
+        adapterConfig: {},
+      },
+      runtime: {
+        sessionId: null,
+        sessionParams: null,
+        sessionDisplayId: null,
+        taskKey: null,
+      },
+      config: {
+        command: "codex",
+        env: {
+          CODEX_HOME: codexHomeDir,
+          OPENAI_API_KEY: "sk-direct-openai",
+        },
+      },
+      context: {
+        paperclipWorkspace: {
+          cwd: workspaceDir,
+          source: "project_primary",
+        },
+      },
+      onLog: async () => {},
+    });
+
+    expect(result.biller).toBe("openai");
+    expect(result.billingType).toBe("api");
+    expect(runAdapterExecutionTargetProcess).toHaveBeenCalledTimes(1);
+    const call = runAdapterExecutionTargetProcess.mock.calls[0] as unknown as
+      | [string, unknown, string, string[], { env: Record<string, string> }]
+      | undefined;
+    expect(call?.[4].env.OPENAI_API_KEY).toBe("sk-direct-openai");
+    expect(call?.[4].env.OPENROUTER_API_KEY).toBeUndefined();
+  });
+});
diff --git a/packages/adapters/codex-local/src/server/execute.ts b/packages/adapters/codex-local/src/server/execute.ts
index 7a02b0584bc..45b856b79a3 100644
--- a/packages/adapters/codex-local/src/server/execute.ts
+++ b/packages/adapters/codex-local/src/server/execute.ts
@@ -499,12 +499,13 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
       Object.assign(env, paperclipBridge.env);
     }
   }
+  const billingEnv = { ...env };
   const effectiveEnv = Object.fromEntries(
     Object.entries({ ...process.env, ...env }).filter(
       (entry): entry is [string, string] => typeof entry[1] === "string",
     ),
   );
-  const billingType = resolveCodexBillingType(effectiveEnv);
+  const billingType = resolveCodexBillingType(billingEnv);
   const runtimeEnv = Object.fromEntries(
     Object.entries(ensurePathInEnv(effectiveEnv)).filter(
       (entry): entry is [string, string] => typeof entry[1] === "string",
@@ -809,7 +810,7 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
       sessionParams: resolvedSessionParams,
       sessionDisplayId: resolvedSessionId,
       provider: "openai",
-      biller: resolveCodexBiller(effectiveEnv, billingType),
+      biller: resolveCodexBiller(billingEnv, billingType),
       model,
       billingType,
       costUsd: null,