diff --git a/apps/api/src/lib/env.ts b/apps/api/src/lib/env.ts
index 296af595..17be2df0 100644
--- a/apps/api/src/lib/env.ts
+++ b/apps/api/src/lib/env.ts
@@ -1,60 +1,115 @@
 import { availableParallelism } from "node:os";
 import { z } from "zod";
 
-const envSchema = z.object({
-  PORT: z.coerce.number().default(1349),
-  AUTH_ENABLED: z
-    .enum(["true", "false"])
-    .default("true")
-    .transform((v) => v === "true"),
-  DEFAULT_USERNAME: z.string().default("admin"),
-  DEFAULT_PASSWORD: z.string().default("admin"),
-  SKIP_MUST_CHANGE_PASSWORD: z
-    .enum(["true", "false"])
-    .default("false")
-    .transform((v) => v === "true"),
-  STORAGE_MODE: z.enum(["local", "s3"]).default("local"),
-  FILE_MAX_AGE_HOURS: z.coerce.number().default(72),
-  CLEANUP_INTERVAL_MINUTES: z.coerce.number().default(60),
-  MAX_UPLOAD_SIZE_MB: z.coerce.number().default(0),
-  MAX_BATCH_SIZE: z.coerce.number().default(0),
-  CONCURRENT_JOBS: z.coerce.number().default(0),
-  MAX_MEGAPIXELS: z.coerce.number().default(0),
-  RATE_LIMIT_PER_MIN: z.coerce.number().default(0),
-  DB_PATH: z.string().default("./data/snapotter.db"),
-  FILES_STORAGE_PATH: z.string().default("./data/files"),
-  WORKSPACE_PATH: z.string().default("./tmp/workspace"),
-  DEFAULT_THEME: z.enum(["light", "dark", "system"]).default("light"),
-  DEFAULT_LOCALE: z.string().default("en"),
-  CORS_ORIGIN: z.string().default(""),
-  MAX_USERS: z.coerce.number().default(0),
-  LOG_LEVEL: z.enum(["fatal", "error", "warn", "info", "debug", "trace"]).default("info"),
-  MAX_WORKER_THREADS: z.coerce.number().default(0),
-  PROCESSING_TIMEOUT_S: z.coerce.number().default(0),
-  MAX_PIPELINE_STEPS: z.coerce.number().default(0),
-  MAX_CANVAS_PIXELS: z.coerce.number().default(0),
-  MAX_SVG_SIZE_MB: z.coerce.number().default(0),
-  MAX_SPLIT_GRID: z.coerce.number().default(100),
-  MAX_PDF_PAGES: z.coerce.number().default(0),
-  SESSION_DURATION_HOURS: z.coerce.number().default(168),
-  LOGIN_ATTEMPT_LIMIT: z.coerce.number().default(500),
-  TRUST_PROXY: z
-    .enum(["true", "false"])
-    .default("true")
-    .transform((v) => v === "true"),
-  ANALYTICS_ENABLED: z
-    .enum(["true", "false"])
-    .default("true")
-    .transform((v) => v === "true"),
-  ANALYTICS_SAMPLE_RATE: z.coerce.number().min(0).max(1).default(1.0),
-  POSTHOG_API_KEY: z.string().default("phc_CVHjGivwWVzh76M5EjijTwP5LpiqWie3EbCzXU7w2Smy"),
-  POSTHOG_HOST: z.string().default("https://us.i.posthog.com"),
-  SENTRY_DSN: z
-    .string()
-    .default(
-      "https://2fd53fc3b3fdc59d02cac044a4f90b71@o4511263372738560.ingest.us.sentry.io/4511264620085248",
-    ),
-});
+const envSchema = z
+  .object({
+    PORT: z.coerce.number().default(1349),
+    AUTH_ENABLED: z
+      .enum(["true", "false"])
+      .default("true")
+      .transform((v) => v === "true"),
+    DEFAULT_USERNAME: z.string().default("admin"),
+    DEFAULT_PASSWORD: z.string().default("admin"),
+    SKIP_MUST_CHANGE_PASSWORD: z
+      .enum(["true", "false"])
+      .default("false")
+      .transform((v) => v === "true"),
+    STORAGE_MODE: z.enum(["local", "s3"]).default("local"),
+    FILE_MAX_AGE_HOURS: z.coerce.number().default(72),
+    CLEANUP_INTERVAL_MINUTES: z.coerce.number().default(60),
+    MAX_UPLOAD_SIZE_MB: z.coerce.number().default(0),
+    MAX_BATCH_SIZE: z.coerce.number().default(0),
+    CONCURRENT_JOBS: z.coerce.number().default(0),
+    MAX_MEGAPIXELS: z.coerce.number().default(0),
+    RATE_LIMIT_PER_MIN: z.coerce.number().default(0),
+    DB_PATH: z.string().default("./data/snapotter.db"),
+    FILES_STORAGE_PATH: z.string().default("./data/files"),
+    WORKSPACE_PATH: z.string().default("./tmp/workspace"),
+    DEFAULT_THEME: z.enum(["light", "dark", "system"]).default("light"),
+    DEFAULT_LOCALE: z.string().default("en"),
+    CORS_ORIGIN: z.string().default(""),
+    MAX_USERS: z.coerce.number().default(0),
+    LOG_LEVEL: z.enum(["fatal", "error", "warn", "info", "debug", "trace"]).default("info"),
+    MAX_WORKER_THREADS: z.coerce.number().default(0),
+    PROCESSING_TIMEOUT_S: z.coerce.number().default(0),
+    MAX_PIPELINE_STEPS: z.coerce.number().default(0),
+    MAX_CANVAS_PIXELS: z.coerce.number().default(0),
+    MAX_SVG_SIZE_MB: z.coerce.number().default(0),
+    MAX_SPLIT_GRID: z.coerce.number().default(100),
+    MAX_PDF_PAGES: z.coerce.number().default(0),
+    SESSION_DURATION_HOURS: z.coerce.number().default(168),
+    LOGIN_ATTEMPT_LIMIT: z.coerce.number().default(500),
+    TRUST_PROXY: z
+      .enum(["true", "false"])
+      .default("true")
+      .transform((v) => v === "true"),
+    OIDC_ENABLED: z
+      .enum(["true", "false"])
+      .default("false")
+      .transform((v) => v === "true"),
+    OIDC_ISSUER_URL: z.string().default(""),
+    OIDC_CLIENT_ID: z.string().default(""),
+    OIDC_CLIENT_SECRET: z.string().default(""),
+    OIDC_SCOPES: z.string().default("openid profile email"),
+    OIDC_AUTO_CREATE_USERS: z
+      .enum(["true", "false"])
+      .default("true")
+      .transform((v) => v === "true"),
+    OIDC_DEFAULT_ROLE: z.string().default("user"),
+    OIDC_AUTO_LINK_USERS: z
+      .enum(["true", "false"])
+      .default("false")
+      .transform((v) => v === "true"),
+    OIDC_PROVIDER_NAME: z.string().default(""),
+    OIDC_CLOCK_TOLERANCE: z.coerce.number().min(0).max(300).default(30),
+    OIDC_USERNAME_CLAIM: z.string().default("preferred_username"),
+    EXTERNAL_URL: z.string().default(""),
+    COOKIE_SECRET: z.string().default(""),
+    ANALYTICS_ENABLED: z
+      .enum(["true", "false"])
+      .default("true")
+      .transform((v) => v === "true"),
+    ANALYTICS_SAMPLE_RATE: z.coerce.number().min(0).max(1).default(1.0),
+    POSTHOG_API_KEY: z.string().default("phc_CVHjGivwWVzh76M5EjijTwP5LpiqWie3EbCzXU7w2Smy"),
+    POSTHOG_HOST: z.string().default("https://us.i.posthog.com"),
+    SENTRY_DSN: z
+      .string()
+      .default(
+        "https://2fd53fc3b3fdc59d02cac044a4f90b71@o4511263372738560.ingest.us.sentry.io/4511264620085248",
+      ),
+  })
+  .superRefine((data, ctx) => {
+    if (data.OIDC_ENABLED) {
+      if (!data.OIDC_ISSUER_URL) {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: "OIDC_ISSUER_URL is required when OIDC_ENABLED=true",
+          path: ["OIDC_ISSUER_URL"],
+        });
+      }
+      if (!data.OIDC_CLIENT_ID) {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: "OIDC_CLIENT_ID is required when OIDC_ENABLED=true",
+          path: ["OIDC_CLIENT_ID"],
+        });
+      }
+      if (!data.OIDC_CLIENT_SECRET) {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: "OIDC_CLIENT_SECRET is required when OIDC_ENABLED=true",
+          path: ["OIDC_CLIENT_SECRET"],
+        });
+      }
+      if (!data.EXTERNAL_URL) {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: "EXTERNAL_URL is required when OIDC_ENABLED=true",
+          path: ["EXTERNAL_URL"],
+        });
+      }
+    }
+  });
 
 export type Env = z.infer<typeof envSchema>;