feat(codex): resolve auth path via CODEX_HOME and host env API

docs/plugins/api.md

@@ -99,6 +99,28 @@ state.counter++
 ctx.host.fs.writeText(statePath, JSON.stringify(state, null, 2))
 ```
 
+## Environment
+
+```typescript
+host.env.get(name: string): string | null
+```
+
+Reads an environment variable by name.
+
+### Behavior
+
+- Returns variable value as string when set
+- Returns `null` when missing
+
+### Example
+
+```javascript
+const codexHome = ctx.host.env.get("CODEX_HOME")
+const authPath = codexHome
+  ? codexHome.replace(/\/+$/, "") + "/auth.json"
+  : "~/.config/codex/auth.json"
+```
+
 ## HTTP
 
 ```typescript

plugins/codex/plugin.js

@@ -1,24 +1,67 @@
 (function () {
-  const AUTH_PATH = "~/.codex/auth.json"
+  const AUTH_FILE = "auth.json"
+  const CONFIG_AUTH_PATHS = ["~/.config/codex", "~/.codex"]
   const CLIENT_ID = "app_EMoamEEZ73f0CkXaXp7hrann"
   const REFRESH_URL = "https://auth.openai.com/oauth/token"
   const USAGE_URL = "https://chatgpt.com/backend-api/wham/usage"
   const REFRESH_AGE_MS = 8 * 24 * 60 * 60 * 1000
 
+  function joinPath(base, leaf) {
+    return base.replace(/[\\/]+$/, "") + "/" + leaf
+  }
+
+  function readCodexHome(ctx) {
+    if (!ctx.host.env || typeof ctx.host.env.get !== "function") {
+      return null
+    }
+
+    try {
+      const value = ctx.host.env.get("CODEX_HOME")
+      if (typeof value !== "string") return null
+      const trimmed = value.trim()
+      return trimmed || null
+    } catch (e) {
+      ctx.host.log.warn("CODEX_HOME read failed: " + String(e))
+      return null
+    }
+  }
+
+  function resolveAuthPath(ctx) {
+    const codexHome = readCodexHome(ctx)
+
+    // If CODEX_HOME is set, use it
+    if (codexHome) {
+      return joinPath(codexHome, AUTH_FILE)
+    }
+
+    // Otherwise, return the first existing auth file path
+    for (const basePath of CONFIG_AUTH_PATHS) {
+      const authPath = joinPath(basePath, AUTH_FILE)
+      if (ctx.host.fs.exists(authPath)) {
+        return authPath
+      }
+    }
+
+    return null
+  }
+
   function loadAuth(ctx) {
-    if (!ctx.host.fs.exists(AUTH_PATH)) {
-      ctx.host.log.warn("auth file not found: " + AUTH_PATH)
+    const authPath = resolveAuthPath(ctx)
+
+    if (!authPath || !ctx.host.fs.exists(authPath)) {
+      ctx.host.log.warn("auth file not found: " + authPath)
       return null
     }
+
     try {
-      const text = ctx.host.fs.readText(AUTH_PATH)
+      const text = ctx.host.fs.readText(authPath)
       const auth = ctx.util.tryParseJson(text)
       if (auth) {
-        ctx.host.log.info("auth loaded from file")
+        ctx.host.log.info("auth loaded from file: " + authPath)
       } else {
         ctx.host.log.warn("auth file exists but not valid JSON")
       }
-      return auth
+      return { auth, authPath }
     } catch (e) {
       ctx.host.log.warn("auth file read failed: " + String(e))
       return null
@@ -32,7 +75,7 @@
     return nowMs - lastMs > REFRESH_AGE_MS
   }
 
-  function refreshToken(ctx, auth) {
+  function refreshToken(ctx, auth, authPath) {
     if (!auth.tokens || !auth.tokens.refresh_token) {
       ctx.host.log.warn("refresh skipped: no refresh token")
       return null
@@ -91,7 +134,7 @@
       auth.last_refresh = new Date().toISOString()
 
       try {
-        ctx.host.fs.writeText(AUTH_PATH, JSON.stringify(auth, null, 2))
+        ctx.host.fs.writeText(authPath, JSON.stringify(auth, null, 2))
         ctx.host.log.info("refresh succeeded, auth file updated")
       } catch (e) {
         ctx.host.log.warn("refresh succeeded but failed to save auth: " + String(e))
@@ -148,11 +191,13 @@
   var PERIOD_WEEKLY_MS = 7 * 24 * 60 * 60 * 1000 // 7 days
 
   function probe(ctx) {
-    const auth = loadAuth(ctx)
-    if (!auth) {
+    const authState = loadAuth(ctx)
+    if (!authState || !authState.auth) {
       ctx.host.log.error("probe failed: not logged in")
       throw "Not logged in. Run `codex` to authenticate."
     }
+    const auth = authState.auth
+    const authPath = authState.authPath
 
     if (auth.tokens && auth.tokens.access_token) {
       const nowMs = Date.now()
@@ -161,7 +206,7 @@
 
       if (needsRefresh(ctx, auth, nowMs)) {
         ctx.host.log.info("token needs refresh (age > " + (REFRESH_AGE_MS / 1000 / 60 / 60 / 24) + " days)")
-        const refreshed = refreshToken(ctx, auth)
+        const refreshed = refreshToken(ctx, auth, authPath)
         if (refreshed) {
           accessToken = refreshed
         } else {
@@ -187,7 +232,7 @@
           refresh: () => {
             ctx.host.log.info("usage returned 401, attempting refresh")
             didRefresh = true
-            return refreshToken(ctx, auth)
+            return refreshToken(ctx, auth, authPath)
           },
         })
       } catch (e) {
@@ -205,7 +250,7 @@
         ctx.host.log.error("usage returned error: status=" + resp.status)
         throw "Usage request failed (HTTP " + String(resp.status) + "). Try again later."
       }
-      
+
       ctx.host.log.info("usage fetch succeeded")
 
       const data = ctx.util.tryParseJson(resp.bodyText)

plugins/codex/plugin.test.js

@@ -18,6 +18,60 @@ describe("codex plugin", () => {
     expect(() => plugin.probe(ctx)).toThrow("Not logged in")
   })
 
+  it("uses CODEX_HOME auth path when env var is set", async () => {
+    const ctx = makeCtx()
+    ctx.host.env.get.mockImplementation((name) => (name === "CODEX_HOME" ? "/tmp/codex-home" : null))
+    ctx.host.fs.writeText("/tmp/codex-home/auth.json", JSON.stringify({
+      tokens: { access_token: "env-token" },
+      last_refresh: new Date().toISOString(),
+    }))
+    ctx.host.fs.writeText("~/.config/codex/auth.json", JSON.stringify({
+      tokens: { access_token: "config-token" },
+      last_refresh: new Date().toISOString(),
+    }))
+    ctx.host.http.request.mockImplementation((opts) => {
+      expect(opts.headers.Authorization).toBe("Bearer env-token")
+      return { status: 200, headers: {}, bodyText: JSON.stringify({}) }
+    })
+
+    const plugin = await loadPlugin()
+    plugin.probe(ctx)
+  })
+
+  it("uses ~/.config/codex/auth.json before ~/.codex/auth.json when env is not set", async () => {
+    const ctx = makeCtx()
+    ctx.host.fs.writeText("~/.config/codex/auth.json", JSON.stringify({
+      tokens: { access_token: "config-token" },
+      last_refresh: new Date().toISOString(),
+    }))
+    ctx.host.fs.writeText("~/.codex/auth.json", JSON.stringify({
+      tokens: { access_token: "legacy-token" },
+      last_refresh: new Date().toISOString(),
+    }))
+    ctx.host.http.request.mockImplementation((opts) => {
+      expect(opts.headers.Authorization).toBe("Bearer config-token")
+      return { status: 200, headers: {}, bodyText: JSON.stringify({}) }
+    })
+
+    const plugin = await loadPlugin()
+    plugin.probe(ctx)
+  })
+
+  it("does not fall back when CODEX_HOME is set but missing auth file", async () => {
+    const ctx = makeCtx()
+    ctx.host.env.get.mockImplementation((name) => (name === "CODEX_HOME" ? "/tmp/missing-codex-home" : null))
+    ctx.host.fs.writeText("~/.config/codex/auth.json", JSON.stringify({
+      tokens: { access_token: "config-token" },
+      last_refresh: new Date().toISOString(),
+    }))
+    ctx.host.fs.writeText("~/.codex/auth.json", JSON.stringify({
+      tokens: { access_token: "legacy-token" },
+      last_refresh: new Date().toISOString(),
+    }))
+    const plugin = await loadPlugin()
+    expect(() => plugin.probe(ctx)).toThrow("Not logged in")
+  })
+
   it("throws when auth json is invalid", async () => {
     const ctx = makeCtx()
     ctx.host.fs.writeText("~/.codex/auth.json", "{bad")

plugins/test-helpers.js

@@ -17,6 +17,9 @@ export const makeCtx = () => {
         readText: (path) => files.get(path),
         writeText: vi.fn((path, text) => files.set(path, text)),
       },
+      env: {
+        get: vi.fn(() => null),
+      },
       keychain: {
         readGenericPassword: vi.fn(),
         writeGenericPassword: vi.fn(),

src-tauri/src/plugin_engine/host_api.rs

@@ -127,6 +127,7 @@ pub fn inject_host_api<'js>(
     let host = Object::new(ctx.clone())?;
     inject_log(ctx, &host, plugin_id)?;
     inject_fs(ctx, &host)?;
+    inject_env(ctx, &host)?;
     inject_http(ctx, &host, plugin_id)?;
     inject_keychain(ctx, &host)?;
     inject_sqlite(ctx, &host)?;
@@ -213,6 +214,18 @@ fn inject_fs<'js>(ctx: &Ctx<'js>, host: &Object<'js>) -> rquickjs::Result<()> {
     Ok(())
 }
 
+fn inject_env<'js>(ctx: &Ctx<'js>, host: &Object<'js>) -> rquickjs::Result<()> {
+    let env_obj = Object::new(ctx.clone())?;
+    env_obj.set(
+        "get",
+        Function::new(ctx.clone(), move |name: String| -> Option<String> {
+            std::env::var(&name).ok()
+        })?,
+    )?;
+    host.set("env", env_obj)?;
+    Ok(())
+}
+
 fn inject_http<'js>(ctx: &Ctx<'js>, host: &Object<'js>, plugin_id: &str) -> rquickjs::Result<()> {
     let http_obj = Object::new(ctx.clone())?;
     let pid = plugin_id.to_string();
@@ -919,6 +932,21 @@ mod tests {
         });
     }
 
+    #[test]
+    fn env_api_exposes_get() {
+        let rt = Runtime::new().expect("runtime");
+        let ctx = Context::full(&rt).expect("context");
+        ctx.with(|ctx| {
+            let app_data = std::env::temp_dir();
+            inject_host_api(&ctx, "test", &app_data, "0.0.0").expect("inject host api");
+            let globals = ctx.globals();
+            let probe_ctx: Object = globals.get("__openusage_ctx").expect("probe ctx");
+            let host: Object = probe_ctx.get("host").expect("host");
+            let env: Object = host.get("env").expect("env");
+            let _get: Function = env.get("get").expect("get");
+        });
+    }
+
     #[test]
     fn redact_value_shows_first_and_last_four() {
         assert_eq!(redact_value("sk-1234567890abcdef"), "sk-1...cdef");