Bird vs Sinch
Bird vs Sinch for SMS
Sinch has two APIs that send SMS. Pick one, and the US registration you cannot skip still sits on a different host, in none of the SDKs they ship. Bird keeps sending, 10DLC registration and delivery events under one host and one key, and every one of them is a tool on a hosted MCP server your agent reaches the moment it connects.
By the numbers
SMS reach
Carrier routes
Delivery speed
What Sinch is great at.
Where Bird is different.
What Sinch is great at
Java and .NET, which Bird does not ship. Their unified SDK covers Node.js, Java, .NET and Python. A Java or .NET shop is better served there, and writes against Bird's HTTP API instead.
Delivery reporting you tune per batch. A batch picks its own delivery_report granularity and can override the service plan's callback URL for that send alone. Bird's events are a workspace-level subscription.
One vendor across a lot of channels. That same SDK also carries voice, numbers, verification, conversation, fax, number lookup and SIP trunking.
Where Bird is different
An agent operates the account itself. The hosted MCP server at mcp.bird.com gives an agent tools that send SMS, read delivery status back and register 10DLC brands against your real workspace, with nothing to install.
A retry that cannot double-send. An Idempotency-Key header on the send makes a repeat safe. Sinch documents no idempotency key on the batch send.
Message intent is a first-class field. Every free-text send carries a category of transactional, marketing, authentication or service, which the Sinch batch has no counterpart for.
The matrix
Capability by capability.
Sinch matches Bird on SDK count and gives finer per-batch control of delivery reports. Bird wins on one host for the whole channel, safe retries, message intent, and an agent surface any MCP client can reach. Read against the Bandwidth page, the one-host row is worth noting twice: Bandwidth splits the channel across two hosts, Sinch spreads it across three surfaces, and the row goes to Bird for a different reason each time.
| Capability | Bird | Sinch | Who wins? |
|---|---|---|---|
| Send request | JSON to /v1/sms/messages on your regional host, with a bearer API key. | JSON to a batches endpoint under your service plan's path, with a bearer token. The primitive is a batch, so to is an array and the text field is body. | |
| Safe retries | An Idempotency-Key header on the send makes a retry safe. | No idempotency key is documented on the batch send, so a retry after a timeout can send twice. client_reference looks like one in a field list but is not: Sinch defines it as an identifier added to the batch's delivery report. | |
| Message intent | Every free-text send carries a category of transactional, marketing, authentication or service. | The batch has no field declaring a message's purpose. client_reference correlates and feedback_enabled asks for confirmation, and neither says why the message was sent. | |
| Hosted MCP server | Bring your own agent. mcp.bird.com is hosted, so Claude Code, Cursor, ChatGPT or your own runtime signs in once and operates the workspace with the same tools. | Sinch publishes an MCP server and its tools do operate the account. It is an npm package each client spawns locally, configured per machine with six environment variables including a project key and secret. | |
| A2P 10DLC registration | /v1/sms/10dlc/* registers brands and campaigns over the API. | Their Registration API registers brands and campaigns over an API, on its own host, and is not one of the products their unified SDK carries. | |
| One host for the whole channel | Sending, 10DLC registration, and delivery events share a base URL and key. | Two of their APIs send SMS, and the US registration you cannot skip is a third surface on a separate host. | |
| Delivery events | A workspace webhook subscribed to sms.*, delivered as JSON signed per Standard Webhooks. | A service plan holds the default callback URL, and each batch can override it and choose one of five delivery_report granularities. | |
| SDK languages | Typed SDKs for TypeScript, Python, Go, and PHP, plus Realtime clients for Swift, Kotlin, and the browser. | A unified SDK for Node.js, Java, .NET, and Python. |
The same send
The send call has a different primitive.
Sending one SMS. Sinch sends a batch, so the recipient is an array, the message text is body, and the payload nests inside sendSMSRequestBody. Bird returns a typed result you can destructure, and category is the field with no Sinch counterpart: every Bird free-text send declares its intent.
Sinch
import { SinchClient } from "@sinch/sdk-core";
const sinch = new SinchClient({
projectId: process.env.SINCH_PROJECT_ID!,
keyId: process.env.SINCH_KEY_ID!,
keySecret: process.env.SINCH_KEY_SECRET!,
smsRegion: "us",
});
const response = await sinch.sms.batches.send({
sendSMSRequestBody: {
from: "+15557654321",
to: ["+15551234567"],
body: "Your table is ready.",
},
});
console.log(response.id);
Bird
import { BirdClient } from "@messagebird/sdk";
const bird = new BirdClient({ apiKey: process.env.BIRD_API_KEY! });
const { data, error } = await bird.sms
.send({
from: "+15557654321",
to: "+15551234567",
text: "Your table is ready.",
category: "transactional",
})
.safe();
if (error) console.error(error.message);
else console.log(data.id, data.status);
What does SMS cost per country?
Every destination country has a published rate on the SMS pricing page, and the carrier and 10DLC fees are itemised separately on SMS carrier fees rather than folded into it. You can price a campaign before you talk to anyone.
Switching cost
Low.
Three things change shape in the send. The service plan comes out of the URL path, the batch collapses to a single recipient, and body becomes text. Your callback URL becomes a workspace webhook subscribed to sms.*, and client_reference has a home in Bird's metadata.
One item is worth starting before the code. Sinch's own documentation says HTTP Basic on the Registration API "is intended for test purposes only" and is "heavily rate limited", and that "production systems should use OAuth access tokens instead" — so if your 10DLC registration runs through that path today, you already have a token lifecycle to retire rather than port. The registration itself is submitted again through Bird, and numbers you own are ported on support's schedule.
Questions people actually ask
Is Bird a good Sinch alternative for SMS?
How different is the send call?
Does Sinch have an MCP server?
Do Bird and Sinch both support A2P 10DLC registration over an API?
What can the agent actually do in my account?
What does Bird SMS cost per country?
Where to go next
The migration guide is the one to start with: it maps the move step by step.