diff --git a/codex-cli/src/components/singlepass-cli-app.tsx b/codex-cli/src/components/singlepass-cli-app.tsx
index 56d1d913..b57b40e4 100644
--- a/codex-cli/src/components/singlepass-cli-app.tsx
+++ b/codex-cli/src/components/singlepass-cli-app.tsx
@@ -5,7 +5,13 @@ import type { FileOperation } from "../utils/singlepass/file_ops";
 
 import Spinner from "./vendor/ink-spinner"; // Third‑party / vendor components
 import TextInput from "./vendor/ink-text-input";
-import { OPENAI_TIMEOUT_MS, getBaseUrl, getApiKey } from "../utils/config";
+import {
+  OPENAI_TIMEOUT_MS,
+  OPENAI_ORGANIZATION,
+  OPENAI_PROJECT,
+  getBaseUrl,
+  getApiKey,
+} from "../utils/config";
 import {
   generateDiffSummary,
   generateEditSummary,
@@ -393,10 +399,19 @@ export function SinglePassApp({
         files,
       });
 
+      const headers: Record<string, string> = {};
+      if (OPENAI_ORGANIZATION) {
+        headers["OpenAI-Organization"] = OPENAI_ORGANIZATION;
+      }
+      if (OPENAI_PROJECT) {
+        headers["OpenAI-Project"] = OPENAI_PROJECT;
+      }
+
       const openai = new OpenAI({
         apiKey: getApiKey(config.provider),
         baseURL: getBaseUrl(config.provider),
         timeout: OPENAI_TIMEOUT_MS,
+        defaultHeaders: headers,
       });
       const chatResp = await openai.beta.chat.completions.parse({
         model: config.model,
diff --git a/codex-cli/src/utils/agent/agent-loop.ts b/codex-cli/src/utils/agent/agent-loop.ts
index aff0e38c..bfbcd95d 100644
--- a/codex-cli/src/utils/agent/agent-loop.ts
+++ b/codex-cli/src/utils/agent/agent-loop.ts
@@ -11,7 +11,13 @@ import type {
 } from "openai/resources/responses/responses.mjs";
 import type { Reasoning } from "openai/resources.mjs";
 
-import { OPENAI_TIMEOUT_MS, getApiKey, getBaseUrl } from "../config.js";
+import {
+  OPENAI_TIMEOUT_MS,
+  OPENAI_ORGANIZATION,
+  OPENAI_PROJECT,
+  getApiKey,
+  getBaseUrl,
+} from "../config.js";
 import { log } from "../logger/log.js";
 import { parseToolCallArguments } from "../parsers.js";
 import { responsesCreateViaChatCompletions } from "../responses.js";
@@ -302,6 +308,10 @@ export class AgentLoop {
         originator: ORIGIN,
         version: CLI_VERSION,
         session_id: this.sessionId,
+        ...(OPENAI_ORGANIZATION
+          ? { "OpenAI-Organization": OPENAI_ORGANIZATION }
+          : {}),
+        ...(OPENAI_PROJECT ? { "OpenAI-Project": OPENAI_PROJECT } : {}),
       },
       ...(timeoutMs !== undefined ? { timeout: timeoutMs } : {}),
     });
diff --git a/codex-cli/src/utils/config.ts b/codex-cli/src/utils/config.ts
index d2b59680..7bd6052e 100644
--- a/codex-cli/src/utils/config.ts
+++ b/codex-cli/src/utils/config.ts
@@ -36,6 +36,8 @@ export const OPENAI_TIMEOUT_MS =
   parseInt(process.env["OPENAI_TIMEOUT_MS"] || "0", 10) || undefined;
 export const OPENAI_BASE_URL = process.env["OPENAI_BASE_URL"] || "";
 export let OPENAI_API_KEY = process.env["OPENAI_API_KEY"] || "";
+export const OPENAI_ORGANIZATION = process.env["OPENAI_ORGANIZATION"] || "";
+export const OPENAI_PROJECT = process.env["OPENAI_PROJECT"] || "";
 
 export function setApiKey(apiKey: string): void {
   OPENAI_API_KEY = apiKey;
diff --git a/codex-cli/src/utils/model-utils.ts b/codex-cli/src/utils/model-utils.ts
index 5670fc44..0d370f27 100644
--- a/codex-cli/src/utils/model-utils.ts
+++ b/codex-cli/src/utils/model-utils.ts
@@ -1,7 +1,12 @@
 import type { ResponseItem } from "openai/resources/responses/responses.mjs";
 
 import { approximateTokensUsed } from "./approximate-tokens-used.js";
-import { getBaseUrl, getApiKey } from "./config";
+import {
+  OPENAI_ORGANIZATION,
+  OPENAI_PROJECT,
+  getBaseUrl,
+  getApiKey,
+} from "./config";
 import { type SupportedModelId, openAiModelInfo } from "./model-info.js";
 import OpenAI from "openai";
 
@@ -22,9 +27,18 @@ async function fetchModels(provider: string): Promise<Array<string>> {
   }
 
   try {
+    const headers: Record<string, string> = {};
+    if (OPENAI_ORGANIZATION) {
+      headers["OpenAI-Organization"] = OPENAI_ORGANIZATION;
+    }
+    if (OPENAI_PROJECT) {
+      headers["OpenAI-Project"] = OPENAI_PROJECT;
+    }
+
     const openai = new OpenAI({
       apiKey: getApiKey(provider),
       baseURL: getBaseUrl(provider),
+      defaultHeaders: headers,
     });
     const list = await openai.models.list();
     const models: Array<string> = [];