cube-js/cube · error

Unexpected output parameter value '${payload.output}'

Error message

Unexpected output parameter value '${payload.output}'

What it means

The /v1/convert endpoint only supports `output: 'rest'` (a SQL string converted to a Cube REST/JSON query). convertQuery throws this Error when the `output` parameter is anything else. Like the input check, it guards the single supported conversion direction.

Source

Thrown at packages/cubejs-api-gateway/src/gateway.ts:1787

      ...query,
      timeDimensions: query.timeDimensions || [],
      contextSymbols: {
        securityContext: this.securityContextExtractor(context),
      },
      requestId: context.requestId
    };
  }

  protected async convertQuery({ payload, context, res }: QueryConvertRequest) {
    try {
      await this.assertApiScope('sql', context.securityContext);

      if (payload.input !== 'sql') {
        throw new Error(`Unexpected input parameter value '${payload.input}'`);
      }

      if (payload.output !== 'rest') {
        throw new Error(`Unexpected output parameter value '${payload.output}'`);
      }

      if (typeof payload.query !== 'string' || !payload.query.trim()) {
        throw new Error('query parameter must be a non-empty string');
      }

      const result = await this.sqlServer.rest4sql(payload.query, context.securityContext);

      await res(result);
    } catch (e: any) {
      this.handleError({
        e,
        context,
        query: payload,
        res,
      });
    }
  }

View on GitHub (pinned to 7d981676b3)

Solutions

1. Set `output` to exactly 'rest' in the request body.
2. Remember the endpoint's sole purpose is SQL -> REST query conversion; for the reverse direction use the /v1/sql endpoint instead.
3. Check for typos/casing: the accepted literal is lowercase 'rest'.

Example fix

// before
{ input: 'sql', output: 'sql', query: 'SELECT count(*) FROM orders' }
// after
{ input: 'sql', output: 'rest', query: 'SELECT count(*) FROM orders' }

if (body.output !== 'rest') throw new Error(`/v1/convert requires output:'rest', got ${JSON.stringify(body.output)}`);

function isConvertOutput(v: unknown): v is 'rest' { return v === 'rest'; }

try {
  return await convertEndpoint(body);
} catch (e) {
  if (String(e?.message).startsWith('Unexpected output parameter')) {
    return await convertEndpoint({ ...body, output: 'rest' });
  }
  throw e;
}

When it happens

Trigger: POST /cubejs-api/v1/convert with body { input: 'sql', output: 'sql' | 'graphql' | 'json' | anything other than 'rest', query: 'SELECT ...' }.

Common situations: Assuming the endpoint can convert REST -> SQL as well (it cannot); passing output mirroring input ('sql' -> 'sql'); IDE extensions or tools generating a wrong default output field.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• Unexpected input parameter value '${payload.input}'
• query parameter must be a non-empty string
• Can't parse date: '${from}'
• Can't parse date: '${to}'
• Can't parse date: '${dateString}'

AI-assisted analysis of cube-js/cube@7d981676b3 (2026-09-02). Data as JSON: /api/errors/2a89bc5b85193ca8. Report an issue: GitHub.