windmill-labs/windmill · error · Error

Script snapshot creation was not successful: ${req.status} -

Error message

Script snapshot creation was not successful: ${req.status} - ${req.statusText} - ${await req.text()}

What it means

When a script is pushed WITH a bundle (bundleContent present), the CLI POSTs multipart form data to /scripts/create_snapshot and requires 201. Any other status throws this error carrying status, statusText and the response body.

Source

Thrown at cli/src/commands/script/script.ts:1038

    );

    const url =
      workspace.remote +
      "api/w/" +
      workspace.workspaceId +
      "/scripts/create_snapshot?" +
      skipIfNoop;
    const req = await fetch(url, {
      method: "POST",
      headers: {
        Authorization: `Bearer ${workspace.token} `,
        ...extraHeaders,
      },
      body: form,
    });
    await detectAuthGatewayChallenge(req, url);
    if (req.status != 201) {
      throw Error(
        `Script snapshot creation was not successful: ${req.status} - ${
          req.statusText
        } - ${await req.text()} `
      );
    }
  }
  return performance.now() - start;
}

/**
 * A script metadata file could not be paired with exactly one script file on
 * disk, so nothing can be deployed for it. Distinct from a deploy that reached
 * the remote and was rejected: callers that can carry on with the rest of a
 * changeset catch this specifically.
 */
export class UnresolvableScriptContentFileError extends Error {}

/**

View on GitHub (pinned to e474e8803c)

Solutions

Read the response body appended to the error for the server's rejection reason
Check permissions of the token for the target workspace
Test whether a proxy/reverse-proxy body-size limit is truncating the multipart upload (raise client_max_body_size on nginx etc.)
Retry after confirming the path is valid and not occupied by an incompatible object

Example fix

// nginx before
client_max_body_size 1m;
// after
client_max_body_size 50m;

Defensive patterns

Strategy: try-catch

Validate before calling

const bundleSize = typeof bundleContent === 'string' ? new Blob([bundleContent]).size : bundleContent.size; if (bundleSize > 50 * 1024 * 1024) console.warn('Bundle may exceed server/proxy body limits');

Try / catch

try { await createScript(bundle, ...); } catch (e) { if (String(e.message).includes('create_snapshot was not successful')) { console.error('Server rejected the snapshot:', e.message); } else throw e; }

Prevention

Raise reverse-proxy client_max_body_size to accommodate bundles
Ensure the token has write permission on the target workspace
Check the response body in the error for the backend's validation reason

When it happens

Trigger: Pushing a bundled script (e.g. with a lockfile/bundle) where the server returns non-201: oversized bundle, invalid multipart payload, auth failure, path conflict, backend validation error.

Common situations: Bundler produced a bundle the backend rejects; token lacks write permission; instance behind a proxy that strips multipart or enforces body-size limits; wrong workspace path.

Understand the failure class

Background: 'Something went wrong' / 'Request failed (500)' / 'HTTP error! status: 404' — what failed HTTP requests actually mean and how to find the real cause — this error's family across 28 libraries.

Related errors

AI-assisted analysis of windmill-labs/windmill@e474e8803c (2026-09-03). Data as JSON: /api/errors/3c8257758da50f58. Report an issue: GitHub.