## Update

**post** `/v1/contacts/{id}`

Updates an existing contact by ID. Only included fields and relationships are modified.

Supports idempotency via the `Idempotency-Key` header.

**[Required scope](/using-the-api/scopes/):** `contacts:update`

**[Rate limit category](/using-the-api/rate-limits/):** Write

### Path Parameters

- `id: string`

  Unique identifier of the contact to update.

### Body Parameters

- `fields: optional object { "$email", "$name", "$profilePhotoUrl" }  or map[string or number or boolean or 2 more]`

  Field values to update — only provided fields are modified; omitted fields are left unchanged. System fields use a `$` prefix (e.g. `$email`); custom attributes use their bare slug. Note: `$name` is an object `{ firstName, lastName }`, not a plain string. Call the <u>[definitions endpoint](/api/resources/contact/methods/definitions)</u> for available fields and types. See <u>[Fields and relationships](/using-the-api/fields-and-relationships/)</u> for value type details.

  - `UnionMember0 = object { "$email", "$name", "$profilePhotoUrl" }`

    - `"$email": optional array of string`

      List of email addresses for the contact (`EMAIL`, multi-value).

    - `"$name": optional object { firstName, lastName }`

      The contact's name. Unlike other resources, this is an object: `{ firstName?: string, lastName?: string }`, not a plain string.

      - `firstName: optional string`

        The contact's first name.

      - `lastName: optional string`

        The contact's last name.

    - `"$profilePhotoUrl": optional string`

      URL of the contact's profile photo (`URL`).

  - `UnionMember1 = map[string or number or boolean or 2 more]`

    - `UnionMember0 = string`

    - `UnionMember1 = number`

    - `UnionMember2 = boolean`

    - `UnionMember3 = array of string or number or boolean or 2 more`

      - `UnionMember0 = string`

      - `UnionMember1 = number`

      - `UnionMember2 = boolean`

      - `UnionMember3 = array of unknown`

      - `UnionMember4 = map[unknown]`

    - `UnionMember4 = map[string or number or boolean or 2 more]`

      - `UnionMember0 = string`

      - `UnionMember1 = number`

      - `UnionMember2 = boolean`

      - `UnionMember3 = array of unknown`

      - `UnionMember4 = map[unknown]`

- `relationships: optional object { "$account" }  or map[object { add, remove, replace } ]`

  Relationship operations to apply. System relationships use a `$` prefix (e.g. `$account`). Each value is an operation object with `add`, `remove`, or `replace`.

  - `Account = object { "$account" }`

    - `"$account": optional object { add, remove, replace }`

      Operation to modify associated accounts.

      - `add: optional string or array of string`

        Entity ID(s) to add to the relationship.

        - `UnionMember0 = string`

        - `UnionMember1 = array of string`

      - `remove: optional string or array of string`

        Entity ID(s) to remove from the relationship.

        - `UnionMember0 = string`

        - `UnionMember1 = array of string`

      - `replace: optional string or array of string`

        Entity ID(s) to set as the entire relationship, replacing all existing associations.

        - `UnionMember0 = string`

        - `UnionMember1 = array of string`

  - `UnionMember1 = map[object { add, remove, replace } ]`

    - `add: optional string or array of string`

      Entity ID(s) to add to the relationship.

      - `UnionMember0 = string`

      - `UnionMember1 = array of string`

    - `remove: optional string or array of string`

      Entity ID(s) to remove from the relationship.

      - `UnionMember0 = string`

      - `UnionMember1 = array of string`

    - `replace: optional string or array of string`

      Entity ID(s) to set as the entire relationship, replacing all existing associations.

      - `UnionMember0 = string`

      - `UnionMember1 = array of string`

### Returns

- `ContactUpdateResponse = object { id, createdAt, fields, 2 more }`

  - `id: string`

    Unique identifier for the entity.

  - `createdAt: string`

    ISO 8601 timestamp of when the entity was created.

  - `fields: map[object { value, valueType } ]`

    Map of field names to their typed values. System fields are prefixed with `$` (e.g. `$name`, `$email`); custom attributes use their bare slug.

    - `value: string or number or boolean or 2 more`

      The field value, or null if unset.

      - `UnionMember0 = string`

      - `UnionMember1 = number`

      - `UnionMember2 = boolean`

      - `UnionMember3 = array of string or number or boolean or 2 more`

        - `UnionMember0 = string`

        - `UnionMember1 = number`

        - `UnionMember2 = boolean`

        - `UnionMember3 = array of unknown`

        - `UnionMember4 = map[unknown]`

      - `UnionMember4 = map[string or number or boolean or 2 more]`

        - `UnionMember0 = string`

        - `UnionMember1 = number`

        - `UnionMember2 = boolean`

        - `UnionMember3 = array of unknown`

        - `UnionMember4 = map[unknown]`

    - `valueType: "ADDRESS" or "CHECKBOX" or "CURRENCY" or 11 more`

      The data type of the field.

      - `"ADDRESS"`

      - `"CHECKBOX"`

      - `"CURRENCY"`

      - `"DATETIME"`

      - `"EMAIL"`

      - `"FULL_NAME"`

      - `"MARKDOWN"`

      - `"MULTI_SELECT"`

      - `"NUMBER"`

      - `"SINGLE_SELECT"`

      - `"SOCIAL_HANDLE"`

      - `"TELEPHONE"`

      - `"TEXT"`

      - `"URL"`

  - `httpLink: string`

    URL to view the entity in the Lightfield web app, or null.

  - `relationships: map[object { cardinality, objectType, values } ]`

    Map of relationship names to their associated entities. System relationships are prefixed with `$` (e.g. `$owner`, `$contact`).

    - `cardinality: string`

      Whether the relationship is `has_one` or `has_many`.

    - `objectType: string`

      The type of the related object (e.g. `account`, `contact`).

    - `values: array of string`

      IDs of the related entities.

### Example

```http
curl https://api.lightfield.app/v1/contacts/$ID \
    -H 'Content-Type: application/json' \
    -H 'Lightfield-Version: 2026-03-01' \
    -H "Authorization: Bearer $API_KEY" \
    -d '{}'
```