Register one sent communication

POST

/v1/communications

const url = 'https://api.fromenance.com/v1/communications';
const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: '{"channel":"email","recipient_hash":"example","message_id":"example","from_address":"example","sent_at":"2026-04-15T12:00:00Z","subject_fingerprint":"example","content_fingerprint":{"simhash":"0x9a4d3c2b1f0e8d7c","sha256":"example"},"link_domains":["example"],"template_id":"example","campaign_id":"example","provider":"api","expires_at":"2026-04-15T12:00:00Z","verify_code":"example"}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}

curl --request POST \
  --url https://api.fromenance.com/v1/communications \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{ "channel": "email", "recipient_hash": "example", "message_id": "example", "from_address": "example", "sent_at": "2026-04-15T12:00:00Z", "subject_fingerprint": "example", "content_fingerprint": { "simhash": "0x9a4d3c2b1f0e8d7c", "sha256": "example" }, "link_domains": [ "example" ], "template_id": "example", "campaign_id": "example", "provider": "api", "expires_at": "2026-04-15T12:00:00Z", "verify_code": "example" }'

Call at send time. Send only the recipient HMAC and the content fingerprint; never the address or the body. Returns the verify code to place in the footer. Supports Idempotency-Key.

Authorizations

ApiKey
register

Request Body

application/json

object

channel

string

Allowed values: email

recipient_hash

required

HMAC-SHA256 of the lowercased, trimmed recipient address keyed with your tenant secret.

string

/^hmac-sha256:[0-9a-f]{64}$/

message_id

required

string

>= 1 characters <= 998 characters

from_address

required

string

>= 3 characters <= 320 characters

sent_at

required

string format: date-time

subject_fingerprint

string

/^[0-9a-f]{64}$/

content_fingerprint

object

simhash

required

string

/^0x[0-9a-fA-F]{1,16}$/

Example

0x9a4d3c2b1f0e8d7c

sha256

required

string

/^[0-9a-f]{64}$/

link_domains

Array<string>

<= 50 items

template_id

string | null

<= 120 characters

campaign_id

string | null

<= 120 characters

provider

string

Allowed values: api sendgrid ses resend postmark mailgun sfmc braze relay journal generic

expires_at

string format: date-time

verify_code

Only when completing a reserved code; otherwise omit and one is issued.

string

<= 9 characters

Responses

201

Registered

application/json

object

required

string

verify_code

required

string

expires_at

required

string

sandbox

required

boolean

Example

{
  "verify_code": "KX73-PQ9G"
}

400

Validation

application/problem+json

object

type

required

string

title

required

string

status

required

integer

detail

string

instance

string

errors

Present on validation problems.

Array<object>

object

path

required

string

message

required

string

request_id

string

Example

{
  "type": "https://docs.fromenance.com/api/errors#validation",
  "title": "Validation failed",
  "status": 400,
  "detail": "recipient_hash must start with hmac-sha256:",
  "instance": "/v1/communications"
}

429

Rate limited

application/problem+json

object

type

required

string

title

required

string

status

required

integer

detail

string

instance

string

errors

Present on validation problems.

Array<object>

object

path

required

string

message

required

string

request_id

string

Example

{
  "type": "https://docs.fromenance.com/api/errors#validation",
  "title": "Validation failed",
  "status": 400,
  "detail": "recipient_hash must start with hmac-sha256:",
  "instance": "/v1/communications"
}