phacility/phabricator · error · Exception

Parameter "%s" must contain a list of transaction descriptio

Error message

Parameter "%s" must contain a list of transaction descriptions, but item with key "%s" is missing a "type" field. Each transaction must have a type field.

What it means

Each entry of the Conduit 'transactions' list must be a dictionary with at least a 'type' key naming the transaction type (e.g. 'title', 'priority'). getRawConduitTransactions() throws this when an item is a dictionary but has no 'type' field.

Source

Thrown at src/applications/transactions/editengine/PhabricatorEditEngine.php:2207

    if (!is_array($xactions)) {
      throw new Exception(
        pht(
          'Parameter "%s" is not a list of transactions.',
          $transactions_key));
    }

    foreach ($xactions as $key => $xaction) {
      if (!is_array($xaction)) {
        throw new Exception(
          pht(
            'Parameter "%s" must contain a list of transaction descriptions, '.
            'but item with key "%s" is not a dictionary.',
            $transactions_key,
            $key));
      }

      if (!array_key_exists('type', $xaction)) {
        throw new Exception(
          pht(
            'Parameter "%s" must contain a list of transaction descriptions, '.
            'but item with key "%s" is missing a "type" field. Each '.
            'transaction must have a type field.',
            $transactions_key,
            $key));
      }

      if (!array_key_exists('value', $xaction)) {
        throw new Exception(
          pht(
            'Parameter "%s" must contain a list of transaction descriptions, '.
            'but item with key "%s" is missing a "value" field. Each '.
            'transaction must have a value field.',
            $transactions_key,
            $key));
      }
    }

View on GitHub (pinned to 5720a38cfe)

Solutions

Add a 'type' key to every transaction dictionary, e.g. {"type":"title","value":"x"}
Use exact lowercase type keys from the method docs or the error listing ('title', 'description', 'priority', 'owner', 'projects', 'subscribers', 'comment', ...)
Validate the shape client-side: every element has both 'type' and 'value'

Example fix

// before
'transactions' => array(array('action' => 'title', 'value' => 'x')),
// Exception: ... item with key "0" is missing a "type" field.

// after
'transactions' => array(array('type' => 'title', 'value' => 'x')),

Defensive patterns

Strategy: validation

Validate before calling

foreach ($parameters['transactions'] as $i => $txn) {
  if (!isset($txn['type'])) {
    // reject before send: every transaction needs 'type'
  }
}

Type guard

function hasRequiredTransactionKeys(array $txn) {
  return isset($txn['type']) && array_key_exists('value', $txn);
}

Try / catch

try {
  $result = $client->callMethod('maniphest.edit', $parameters);
} catch (ConduitClientException $ex) {
  if (strpos($ex->getMessage(), 'missing a "type" field') !== false) {
    // add the type key; the failing index is in the message
  } else {
    throw $ex;
  }
}

Prevention

Copy type keys verbatim from the method documentation; they are lowercase
Construct transactions only through a helper that enforces type+value keys
When porting old maniphest.update scripts, rewrite the payload shape, not just the method name

When it happens

Trigger: Sending transactions => [{"value":"x"}] (value only), or using a different key name such as 'transaction', 'action', or 'operation' instead of 'type'.

Common situations: Porting scripts from the older pre-edit-engine API (maniphest.update used 'type' at the top level with different semantics); guessing field names instead of copying them from the method documentation; typos like 'Type' (case-sensitive).

Related errors

AI-assisted analysis of phacility/phabricator@5720a38cfe (2026-08-21). Data as JSON: /api/errors/9b73537225d951c7. Report an issue: GitHub.