Field mapping

A step's settings map each input field of its action to a value: fixed text, or a {{ }} expression that reads the trigger, an earlier step or the current loop item. Claude or the assistant writes the mappings when it builds the automation, using the exact field names the action declares.

What a mapping looks like

Mappings live in the step's settings object. Each key is an input field name; each value is text, an expression, or both:

{
  "step_id": "create_deal",
  "type": "assembly",
  "settings": {
    "Deal Name": "Order {{ trigger.body.order_id }}",
    "Amount": "{{ trigger.body.total }}",
    "Contact ID": "{{ steps.find_contact.output.id }}",
    "Pipeline": "Online sales"
  }
}

• Pipeline is fixed text, sent as written.
• Amount and Contact ID read earlier data.
• Deal Name mixes text and an expression.

A dropdown setting stores the option's value and its label together, for example {"value": "12", "label": "Online sales"}.

Where a value can come from

A polling trigger's record fields are read directly under trigger. Loop values exist only inside the loop's body.

Field names with spaces

Dotted access works only for names made of letters, digits and underscores. A name with a space or other character uses quoted brackets:

{{ trigger['Appointment Start Time'] }}
{{ steps.lookup_client.output['Email Address'] }}

Field names are case-sensitive. A reference to a field that does not exist renders as empty text rather than failing the step, so a misspelled name shows up as a blank value in the app, not as an error.

Reading a step inside a branch or loop

Step outputs are stored in one map keyed by step ID, so a step after a condition or loop can read a step inside it. A step that did not run, because its branch was not taken, has no output and reads as empty. Two branches of the same condition, and two branches of a parallel step, cannot read each other.

Expressions

The text inside {{ }} is an expr-lang expression, so a mapping can compute a value inline instead of needing a separate step:

The date helpers return UTC. For timezone shifts and date arithmetic, use the Transform Date Time app; for anything longer than an expression, a script step.

A condition's test and a loop's list are written as bare expressions without braces, for example trigger.amount > 100. See Conditions, loops and parallel branches.

Types and conversion

A setting that is exactly one expression keeps the expression's type: a number stays a number, a list stays a list. A setting that mixes text and expressions is always text.

Each input field of an action declares a datatype: string, enum, number, integer, bool, array or object. When the step runs, the mapped value is converted to that datatype before it is sent:

• A value that cannot be converted fails the run with an error naming the field, instead of sending a value the app would reject.
• A blank value is never converted to false or 0. It stays blank.
• A list mapped to a single-value field is passed through unchanged, because some actions process each element.

Leaving a field alone and clearing it

• An unmapped field is not sent. Most apps then keep the current value, but an app whose update replaces the whole record may not.
• A field mapped to an expression that comes out as empty text is not sent when the field is declared as a number, integer, boolean, array or object. For a text field, whether a blank value is sent depends on how the action was built, so an update action can overwrite a stored value with an empty one.
• To erase a value on purpose, ask Claude to clear that field on the step, for example "clear the phone field on the update contact step". Clearing works only when the action declares how that app clears the field. For other actions, Claude's request to clear is refused rather than sending a blank.

A clear is unconditional: it cannot depend on data in the run.

Viewing an automation's mappings

The field mappings page lists every app action step in an automation, including steps inside conditions and loops. For each step it shows every input field the action declares, with its datatype, whether it is required, its help text and the mapped value. A cleared field shows as "Clears this field", with a note when the action does not support the clear or the app ignores it. Filters narrow the list to required fields, mapped fields or a text search. The page is read-only.

Open it at https://app.apiant.ai/mappings?uuid=<automation UUID>. The gear menu's Manage > Get UUID shows the automation's UUID.

The page shows one table per action step, with a search box and Required only and Mapped only filters above.

Importing mappings from a CSV

If you keep field mappings in a spreadsheet, paste the rows into the conversation, or attach the file in a client that can read it. No APIANT tool reads the file itself.

1. Claude looks for source and destination columns, such as "Source Field" and "Destination Field", or "From" and "To".
2. Claude reads the target action's real input fields.
3. Each spreadsheet name is matched to a field: exact match first, then case-insensitive, then partial, then by meaning, so "Phone" can match mobile_phone.
4. Claude asks you about any name that matches more than one field.
5. The matched mappings are written into the step's settings.

Troubleshooting

Next steps

• Actions and built-in apps
• Conditions, loops and parallel branches
• Subroutines and calling automations
• Testing an automation