## Update a contact

`client.Contact.Update(ctx, id, body) (*ContactUpdateResponse, error)`

**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

### Parameters

- `id string`

  Unique identifier of the contact to update.

- `body ContactUpdateParams`

  - `Fields param.Field[map[string, ContactUpdateParamsFieldUnion]]`

    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.

    - `map[string, ContactUpdateParamsFieldUnion]`

      - `string`

      - `float64`

      - `bool`

      - `type ContactUpdateParamsFieldArray []string`

      - `type ContactUpdateParamsFieldAddress struct{…}`

        - `City string`

          City name.

        - `Country string`

          2-letter ISO 3166-1 alpha-2 country code.

        - `Latitude float64`

          Latitude coordinate.

        - `Longitude float64`

          Longitude coordinate.

        - `PostalCode string`

          Postal or ZIP code.

        - `State string`

          State or province.

        - `Street string`

          Street address line 1.

        - `Street2 string`

          Street address line 2.

      - `type ContactUpdateParamsFieldFullName struct{…}`

        - `FirstName string`

          The contact's first name.

        - `LastName string`

          The contact's last name.

  - `Relationships param.Field[map[string, ContactUpdateParamsRelationship]]`

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

    - `map[string, ContactUpdateParamsRelationship]`

      - `Add ContactUpdateParamsRelationshipAddUnion`

        Entity ID(s) to add to the relationship.

        - `string`

        - `type ContactUpdateParamsRelationshipAddArray []string`

      - `Remove ContactUpdateParamsRelationshipRemoveUnion`

        Entity ID(s) to remove from the relationship.

        - `string`

        - `type ContactUpdateParamsRelationshipRemoveArray []string`

      - `Replace ContactUpdateParamsRelationshipReplaceUnion`

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

        - `string`

        - `type ContactUpdateParamsRelationshipReplaceArray []string`

### Returns

- `type ContactUpdateResponse struct{…}`

  - `ID string`

    Unique identifier for the entity.

  - `CreatedAt string`

    ISO 8601 timestamp of when the entity was created.

  - `Fields map[string, ContactUpdateResponseField]`

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

    - `Value ContactUpdateResponseFieldValueUnion`

      The field value, or null if unset.

      - `string`

      - `float64`

      - `bool`

      - `type ContactUpdateResponseFieldValueArray []string`

      - `type ContactUpdateResponseFieldValueAddress struct{…}`

        - `City string`

          City name.

        - `Country string`

          2-letter ISO 3166-1 alpha-2 country code.

        - `Latitude float64`

          Latitude coordinate.

        - `Longitude float64`

          Longitude coordinate.

        - `PostalCode string`

          Postal or ZIP code.

        - `State string`

          State or province.

        - `Street string`

          Street address line 1.

        - `Street2 string`

          Street address line 2.

      - `type ContactUpdateResponseFieldValueFullName struct{…}`

        - `FirstName string`

          The contact's first name.

        - `LastName string`

          The contact's last name.

    - `ValueType string`

      The data type of the field.

      - `const ContactUpdateResponseFieldValueTypeAddress ContactUpdateResponseFieldValueType = "ADDRESS"`

      - `const ContactUpdateResponseFieldValueTypeCheckbox ContactUpdateResponseFieldValueType = "CHECKBOX"`

      - `const ContactUpdateResponseFieldValueTypeCurrency ContactUpdateResponseFieldValueType = "CURRENCY"`

      - `const ContactUpdateResponseFieldValueTypeDatetime ContactUpdateResponseFieldValueType = "DATETIME"`

      - `const ContactUpdateResponseFieldValueTypeEmail ContactUpdateResponseFieldValueType = "EMAIL"`

      - `const ContactUpdateResponseFieldValueTypeFullName ContactUpdateResponseFieldValueType = "FULL_NAME"`

      - `const ContactUpdateResponseFieldValueTypeMarkdown ContactUpdateResponseFieldValueType = "MARKDOWN"`

      - `const ContactUpdateResponseFieldValueTypeMultiSelect ContactUpdateResponseFieldValueType = "MULTI_SELECT"`

      - `const ContactUpdateResponseFieldValueTypeNumber ContactUpdateResponseFieldValueType = "NUMBER"`

      - `const ContactUpdateResponseFieldValueTypeSingleSelect ContactUpdateResponseFieldValueType = "SINGLE_SELECT"`

      - `const ContactUpdateResponseFieldValueTypeSocialHandle ContactUpdateResponseFieldValueType = "SOCIAL_HANDLE"`

      - `const ContactUpdateResponseFieldValueTypeTelephone ContactUpdateResponseFieldValueType = "TELEPHONE"`

      - `const ContactUpdateResponseFieldValueTypeText ContactUpdateResponseFieldValueType = "TEXT"`

      - `const ContactUpdateResponseFieldValueTypeURL ContactUpdateResponseFieldValueType = "URL"`

  - `HTTPLink string`

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

  - `Relationships map[string, ContactUpdateResponseRelationship]`

    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 []string`

      IDs of the related entities.

  - `UpdatedAt string`

    ISO 8601 timestamp of when the entity was last updated, or null.

  - `ExternalID string`

    External identifier for the entity, or null if unset.

### Example

```go
package main

import (
  "context"
  "fmt"

  "github.com/Lightfld/lightfield-go"
  "github.com/Lightfld/lightfield-go/option"
)

func main() {
  client := githubcomlightfldlightfieldgo.NewClient(
    option.WithAPIKey("My API Key"),
  )
  contactUpdateResponse, err := client.Contact.Update(
    context.TODO(),
    "id",
    githubcomlightfldlightfieldgo.ContactUpdateParams{

    },
  )
  if err != nil {
    panic(err.Error())
  }
  fmt.Printf("%+v\n", contactUpdateResponse.ID)
}
```

#### Response

```json
{
  "id": "id",
  "createdAt": "createdAt",
  "fields": {
    "foo": {
      "value": "string",
      "valueType": "ADDRESS"
    }
  },
  "httpLink": "httpLink",
  "relationships": {
    "foo": {
      "cardinality": "cardinality",
      "objectType": "objectType",
      "values": [
        "string"
      ]
    }
  },
  "updatedAt": "updatedAt",
  "externalId": "externalId"
}
```