windmill-labs/windmill · error

No defaultTs defined in your wmill.yaml. Using 'bun' as defa

Error message

No defaultTs defined in your wmill.yaml. Using 'bun' as default.

What it means

Defaulting notice from readConfigFile: wmill.yaml has no defaultTs entry, so the CLI falls back to 'bun' as the default TypeScript runtime for new scripts and language inference. Purely informational; behavior is well-defined with the fallback.

Source

Thrown at cli/src/core/conf.ts:282

        }
      }
    } else if (conf?.workspaces) {
      // If both workspaces and any legacy key exist, warn and use workspaces
      for (const legacyKey of ["gitBranches", "environments", "git_branches"] as const) {
        if ((conf as any)[legacyKey]) {
          log.warn(
            `⚠️  Both 'workspaces' and '${legacyKey}' found in wmill.yaml. Using 'workspaces' and ignoring '${legacyKey}'.`
          );
        }
      }
    }
    // Clean legacy keys from in-memory config
    delete conf?.gitBranches;
    delete (conf as any)?.environments;
    delete conf?.git_branches;

    if (conf?.defaultTs == undefined) {
      log.warn(
        "No defaultTs defined in your wmill.yaml. Using 'bun' as default."
      );
    }

    // Initialize global nonDottedPaths setting from config
    setNonDottedPaths(conf?.nonDottedPaths ?? false);

    const syncBehaviorVersion = parseSyncBehavior(conf?.syncBehavior);
    if (syncBehaviorVersion > SUPPORTED_SYNC_BEHAVIOR_VERSION) {
      log.error(
        `Your wmill.yaml specifies syncBehavior: ${conf!.syncBehavior}, but this CLI only supports up to v${SUPPORTED_SYNC_BEHAVIOR_VERSION}. Run 'wmill upgrade' to update.`
      );
      process.exit(1);
    }

    return typeof conf == "object" ? conf : ({} as SyncOptions);
  } catch (e) {
    if (

View on GitHub (pinned to e474e8803c)

Solutions

1. Add 'defaultTs: <bun|nativets|deno>' to wmill.yaml to make it explicit
2. No action needed if 'bun' is the intended default

When it happens

Trigger: Thrown at cli/src/core/conf.ts:282 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of windmill-labs/windmill@e474e8803c (2026-09-03). Data as JSON: /api/errors/cbee99e2260147c9. Report an issue: GitHub.