fix(opencode): send Codex-compatible OAuth request identity headers

packages/opencode/src/plugin/openai/codex.ts

@@ -12,6 +12,8 @@ const ISSUER = "https://auth.openai.com"
 const CODEX_API_ENDPOINT = "https://chatgpt.com/backend-api/codex/responses"
 const OAUTH_PORT = 1455
 const OAUTH_POLLING_SAFETY_MARGIN_MS = 3000
+const CODEX_ORIGINATOR = "codex_cli_rs"
+const CODEX_USER_AGENT = `codex_cli_rs/0.0.0 (OpenCode/${InstallationVersion}) (${os.platform()} ${os.release()})`
 const ALLOWED_MODELS = new Set(["gpt-5.5", "gpt-5.3-codex-spark", "gpt-5.4", "gpt-5.4-mini"])
 const DISALLOWED_MODELS = new Set(["gpt-5.5-pro"])
 
@@ -539,8 +541,8 @@ export async function CodexAuthPlugin(input: PluginInput, options: CodexAuthPlug
     },
     "chat.headers": async (input, output) => {
       if (input.model.providerID !== "openai") return
-      output.headers.originator = "opencode"
-      output.headers["User-Agent"] = `opencode/${InstallationVersion} (${os.platform()} ${os.release()}; ${os.arch()})`
+      output.headers.originator = CODEX_ORIGINATOR
+      output.headers["User-Agent"] = CODEX_USER_AGENT
       output.headers["session-id"] = input.sessionID
       // Temporary fetch-layer hack: title generation currently shares the conversation
       // session ID, so the OpenAI plugin marks it for HTTP fallback until transport

packages/opencode/test/plugin/codex.test.ts

@@ -1,4 +1,6 @@
 import { describe, expect, test } from "bun:test"
+import { InstallationVersion } from "@opencode-ai/core/installation/version"
+import os from "os"
 import {
   CodexAuthPlugin,
   parseJwtClaims,
@@ -149,6 +151,18 @@ describe("plugin.codex", () => {
     await enabled.dispose?.()
   })
 
+  test("sends Codex-compatible request identity headers", async () => {
+    const hooks = await CodexAuthPlugin({} as never)
+    const output = { headers: {} as Record<string, string> }
+
+    await hooks["chat.headers"]?.({ model: { providerID: "openai" } } as never, output)
+
+    expect(output.headers.originator).toBe("codex_cli_rs")
+    expect(output.headers["User-Agent"]).toBe(
+      `codex_cli_rs/0.0.0 (OpenCode/${InstallationVersion}) (${os.platform()} ${os.release()})`,
+    )
+  })
+
   test("deduplicates concurrent Codex token refreshes", async () => {
     let auth = {
       type: "oauth" as const,