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
DG	Event Sink
DN	Domain
ES	Sync List
EY	Operator Type
FJ	Flex Plugin Service Release
FN	Flex Context Execution Resource
FT	Flex Step
FW	Flex Workflow
GA	Conversational Intelligence Service
GT	Intelligence Service
HH	Tollfree Number Verification
HJ	Verification Service
HX	Message Content
IG	Conversations Address Configuration
IM	Chat Message
IP	SIP IP Address
IS	Chat Service
IT	Twilio End User
KC	Phone Number Proxy Session
KD	Flex Interaction Resource
KP	Phone Number Proxy Participant
KS	Phone Number Proxy
MB	Chat Member
ME	Media
MG	Messaging Service
MM	Message
NO	Notification
PA	Recording Grouping
PN	Phone Number
QE	Association with External Campaign
RD	Regulatory Supporting Document
RE	Recording
RL	Role
RM	Room
RN	Regulatory Policy Number
RT	Recording Track
SC	Shortcode
SD	SIP Domain
SK	API Key
SM	Message
TR	Transcription
UO	Flex Interaction Channel
US	User
UT	Flex Interaction Channel Participant
VA	Service Attempting Verification
VE	Verification Check
VL	Verification Attempt
VT	Vetting Record
WA	TaskRouter Assignment Activity
WQ	TaskRouter Task Assignment Activity
WS	TaskRouter Workspace
WT	TaskRouter Workspace Task
WW	TaskRouter Workflow
XB	Marketplace Listing
XE	WhatsApp Sender
YF	Verification Factor
ZB	Serverless Build

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}