serverless/serverless · error · ServerlessError

DOMAIN_CONFIG_AMBIGUOUS_BOOLEAN

DOMAIN_CONFIG_AMBIGUOUS_BOOLEAN

Error message

${Globals.pluginName}: Ambiguous boolean config: "${value}"

What it means

Thrown by evaluateBoolean when a custom-domains boolean config field (enabled, createRoute53Record, createRoute53IPv6Record, autoDomain, preserveExternalPathMappings, splitHorizonDns) is set to a value that is not undefined and does not stringify to true/1/false/0. The function accepts booleans and the strings 'true','1','false','0' (case-insensitive, trimmed) and rejects everything else.

Source

Thrown at packages/serverless/lib/plugins/aws/domains/utils.js:38

 * @param {boolean|string} value the config value provided
 * @param {boolean} defaultValue the default value to return, if config value is undefined
 * @returns {boolean} the parsed boolean from the config value, or the default value
 */
function evaluateBoolean(value, defaultValue) {
  if (value === undefined) {
    return defaultValue
  }

  const s = value.toString().toLowerCase().trim()
  const trueValues = ['true', '1']
  const falseValues = ['false', '0']
  if (trueValues.indexOf(s) >= 0) {
    return true
  }
  if (falseValues.indexOf(s) >= 0) {
    return false
  }
  throw new ServerlessError(
    `${Globals.pluginName}: Ambiguous boolean config: "${value}"`,
    ServerlessErrorCodes.domains.DOMAIN_CONFIG_AMBIGUOUS_BOOLEAN,
  )
}

/**
 * Iterate through the pages of an AWS SDK v3 response and collect them into a single array
 *
 * @param {Object} client - The AWS SDK v3 client instance
 * @param {string} resultsKey - The key name in the response that contains the items to return
 * @param {string} nextTokenKey - The request key name to append to the request that has the paging token value
 * @param {string} nextResponseTokenKey - The response key name that has the next paging token value
 * @param {Object} command - The AWS SDK v3 Command instance to execute
 * @returns {Promise<Array>} Promise that resolves to an array of results
 */
async function getAWSPagedResults(
  client,
  resultsKey,

View on GitHub (pinned to b9d7ea51c8)

Solutions

1. Use YAML booleans (true/false) or the digits 1/0.
2. Remove the key to accept its documented default (each field has its own default).
3. If the value comes from a variable, ensure the resolver yields true/false rather than a word.

Example fix

# before
customDomains:
  - enabled: 'yes'
# after
customDomains:
  - enabled: true

const BOOL_KEYS = ['enabled', 'createRoute53Record', 'createRoute53IPv6Record', 'autoDomain', 'preserveExternalPathMappings', 'splitHorizonDns']
function isValidBool(v) {
  if (v === undefined) return true
  return ['true', '1', 'false', '0'].includes(String(v).toLowerCase().trim())
}
function validateDomainBools(domain) {
  return BOOL_KEYS.every((k) => isValidBool(domain[k]))
}

function isParseableBoolean(v) {
  return v === undefined || typeof v === 'boolean' || ['true','1','false','0'].includes(String(v).toLowerCase().trim())
}

When it happens

Trigger: Setting a boolean field to 'yes', 'no', 'on', 'off', 'enabled', 'Y', 'N', or any non-zero number like 2.

Common situations: Using YAML barewords yes/no/on/off that a stricter loader leaves as strings; passing a free-form truthy string; confusing this plugin's strict parser with another tool's lenient one.

Related errors

• DOMAIN_CONFIG_INVALID_ACCESS_MODE
• DOMAIN_CONFIG_INVALID_ROUTING_POLICY
• DOMAIN_CONFIG_ROUTING_POLICY_EDGE_INCOMPATIBLE
• AWS_ROUTE53_MISSING_HOSTED_ZONE
• NO_AGENTS_DEFINED

AI-assisted analysis of serverless/serverless@b9d7ea51c8 (2026-08-13). Data as JSON: /api/errors/4209b5b386daaf81. Report an issue: GitHub.