Simulate an inbound SMS (test keys only)

POST /v1/test/inbound

Send your API key as a bearer token: Authorization: Bearer ssms_sk_.... Test keys run this endpoint against the sandbox; see Authentication for key modes and scopes.

Request body

JSON (Content-Type: application/json).

Field	Type	Required	Description
`to`	string	Yes	One of your sandbox numbers
`from`	string	Yes
`body`	string	Yes

Responses

Status	Meaning	Body
201	Simulated inbound message	`Message`
401	Missing, malformed, or revoked API key	`Error`
402	Billable live calls only: the prepaid credit balance cannot cover the call (insufficient_credits); nothing was done or charged	`Error`
403	Live keys not allowed	`Error`
429	Rate limit or quota exceeded	`Error`

201: `Message` fields

Field	Type	Description
`id`	string	Example: `msg_a1B2c3D4e5F6g7H8`.
`object`	`message`
`to`	string	Example: `+15005550006`.
`from`	string	Example: `+15005550100`.
`body`	string
`direction`	`outbound`, `inbound`
`status`	`queued`, `sent`, `delivered`, `failed`, `received`
`test`	boolean
`simulated`	boolean	True when nothing was handed to a carrier: every test-key message except one sent to your own verified phone. Always false on live messages. A simulated message still reaches `delivered`.
`notice`	string	Only on the response to POST /messages. Present when a test-key send to a real-looking number was simulated: says nothing was sent and how to send for real.
`schedule_id`	string	The recurring schedule this message is an occurrence of. Present only when set.
`created_at`	string (date-time)
`media`	array of string (uri)	MMS attachments (inbound today).
`sent_by`	string	Console user or API key that composed it.
`failure_reason`	string	The carrier's raw text for a failed send. Kept for compatibility; see `failure`.
`attempts`	integer	Live sends: carrier submissions so far. More than 1 means it was retried.
`next_attempt_at`	string (date-time)	Present while queued for an automatic carrier retry.
`receipt_status`	`missing`	The carrier accepted the message but sent no delivery report within 72 hours. status stays sent.
`customer_id`	string	The customer this is attributed to. Present only when set.
`timeline`	array of object	Every status transition, oldest first. Inbound messages have a single `received`.
`timeline[].status`	`accepted`, `validated`, `queued`, `sent_to_carrier`, `carrier_accepted`, `retry_scheduled`, `delivered`, `failed`, `received`
`timeline[].at`	string (date-time)
`timeline[].attempt`	integer	Carrier attempt this step belongs to (from sent_to_carrier on).
`segments`	integer	Parts the body is split into (GSM-7: 160, then 153 each; UCS-2: 70, then 67). Example: `1`.
`encoding`	`gsm7`, `ucs2`
`price`	object	What this message costs, in USD. One all-in rate per outbound message; carrier fees are included (a 0 line). Null on messages sent before prices were recorded. Nullable.
`price.total`	number	Example: `0.009`.
`price.currency`	`usd`
`price.breakdown`	array of object
`price.breakdown[].label`	string
`price.breakdown[].amount`	number
`destination_carrier`	string	The recipient's mobile carrier, when a cached lookup knows it. Nullable.
`failure`	Failure	Null unless status is `failed`. Nullable.

Errors

Status	When
401	Missing, malformed, or revoked API key
402	Billable live calls only: the prepaid credit balance cannot cover the call (insufficient_credits); nothing was done or charged
403	Live keys not allowed
429	Rate limit or quota exceeded

Every error has the same JSON shape, and request_id matches the X-Request-Id response header. Errors lists every code and what to do about it.

json

{
  "error": {
    "code": "invalid_request",
    "message": "What went wrong, in plain words.",
    "param": "the_field",
    "request_id": "req_a1B2c3D4e5F6g7H8"
  }
}

Examples

curl

bash

curl -X POST "https://api.joinsimplesms.com/v1/test/inbound" \
  -H "Authorization: Bearer $SIMPLESMS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "to": "+14155550132",
  "from": "+15005550100",
  "body": "Hello from SimpleSMS"
}'

Node.js

The Node.js SDK does not wrap this endpoint yet; call it with fetch.

javascript

const res = await fetch('https://api.joinsimplesms.com/v1/test/inbound', {
  method: 'POST',
  headers: {
    Authorization: `Bearer ${process.env.SIMPLESMS_API_KEY}`,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "to": "+14155550132",
    "from": "+15005550100",
    "body": "Hello from SimpleSMS"
  }),
});

if (!res.ok) throw new Error((await res.json()).error.message);
const data = await res.json();

Python

The Python SDK does not wrap this endpoint yet; call it over HTTP.

python

import json, os, urllib.request

req = urllib.request.Request(
    "https://api.joinsimplesms.com/v1/test/inbound",
    method="POST",
    headers={
        "Authorization": f"Bearer {os.environ['SIMPLESMS_API_KEY']}",
        "Content-Type": "application/json",
    },
    data=json.dumps({
        "to": "+14155550132",
        "from": "+15005550100",
        "body": "Hello from SimpleSMS"
    }).encode(),
)
with urllib.request.urlopen(req) as res:
    data = json.load(res)