What is a String Identifier (SID)?

A unique key string that Twilio uses to identify specific resources.

Twilio identifies every resource with a 34-character String Identifier (SID). This SID consists of a two-letter prefix followed by 32 hexadecimal digits. You can use the first two characters of the SID to identify its type. The following table includes many of the common prefixes for SIDs. Most API reference pages include multiple SIDs in their list of properties.

Component

Prefix	Component
AC	Account
AD	Physical Address
AI	AlphaSender
AL	Access List
AP	Application
BN	Brand
BU	Regulatory Bundle
CA	Call
CF	Conference
CH	Conversation
CL	Credential List
CN	Connection
CP	Conference Participant
CR	Credential

Examples of SIDs in API requests

Many API requests to Twilio include a resource SID in their response. To fetch information about that resource, search for and use this SID.

The following example creates an SMS message:

Create a new text message

1// Download the helper library from https://www.twilio.com/docs/node/install
2const twilio = require("twilio"); // Or, for ESM: import twilio from "twilio";
3
4// Find your Account SID and Auth Token at twilio.com/console
5// and set the environment variables. See http://twil.io/secure
6const accountSid = process.env.TWILIO_ACCOUNT_SID;
7const authToken = process.env.TWILIO_AUTH_TOKEN;
8const client = twilio(accountSid, authToken);
9
10async function createMessage() {
11  const message = await client.messages.create({
12    body: "This will be the body of the new message!",
13    from: "+14155552344",
14    to: "alex@example.com",
15  });
16
17  console.log(message.sid);
18}
19
20createMessage();

Response

1{
2  "account_sid": "ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
3  "api_version": "2010-04-01",
4  "body": "This will be the body of the new message!",
5  "date_created": "Thu, 24 Aug 2023 05:01:45 +0000",
6  "date_sent": "Thu, 24 Aug 2023 05:01:45 +0000",
7  "date_updated": "Thu, 24 Aug 2023 05:01:45 +0000",
8  "direction": "outbound-api",
9  "error_code": null,
10  "error_message": null,
11  "from": "+14155552344",
12  "num_media": "0",
13  "num_segments": "1",
14  "price": null,
15  "price_unit": null,
16  "messaging_service_sid": "MGaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
17  "sid": "SMaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
18  "status": "queued",
19  "subresource_uris": {
20    "media": "/2010-04-01/Accounts/ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/Messages/SMaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/Media.json"
21  },
22  "to": "alex@example.com",
23  "uri": "/2010-04-01/Accounts/ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/Messages/SMaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.json"
24}

The JSON response to this API request from Twilio returns a property labeled sid. To retrieve this specific message, use the message SID with the SM prefix. This second call returns data about that specific resource.

Fetch a Message by SID

1// Download the helper library from https://www.twilio.com/docs/node/install
2const twilio = require("twilio"); // Or, for ESM: import twilio from "twilio";
3
4// Find your Account SID and Auth Token at twilio.com/console
5// and set the environment variables. See http://twil.io/secure
6const accountSid = process.env.TWILIO_ACCOUNT_SID;
7const authToken = process.env.TWILIO_AUTH_TOKEN;
8const client = twilio(accountSid, authToken);
9
10async function fetchMessage() {
11  const message = await client
12    .messages("SMaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
13    .fetch();
14
15  console.log(message.status);
16}
17
18fetchMessage();

Response

1{
2  "account_sid": "ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
3  "api_version": "2010-04-01",
4  "body": "testing",
5  "date_created": "Fri, 24 May 2019 17:18:27 +0000",
6  "date_sent": "Fri, 24 May 2019 17:18:28 +0000",
7  "date_updated": "Fri, 24 May 2019 17:18:28 +0000",
8  "direction": "outbound-api",
9  "error_code": 30007,
10  "error_message": "Carrier violation",
11  "from": "+12019235161",
12  "messaging_service_sid": "MGaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
13  "num_media": "0",
14  "num_segments": "1",
15  "price": "-0.00750",
16  "price_unit": "USD",
17  "sid": "SMaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
18  "status": "sent",
19  "subresource_uris": {
20    "media": "/2010-04-01/Accounts/ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/Messages/SMb7c0a2ce80504485a6f653a7110836f5/Media.json",
21    "feedback": "/2010-04-01/Accounts/ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/Messages/SMb7c0a2ce80504485a6f653a7110836f5/Feedback.json"
22  },
23  "to": "+18182008801",
24  "uri": "/2010-04-01/Accounts/ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/Messages/SMb7c0a2ce80504485a6f653a7110836f5.json"
25}