App builderCompatible per the specificationChecked on 10/28/2026

Connect v0 to Postal

Connect Postal to v0 so it can look up your domains and templates and send test emails while it generates the app.

How you sign in: Account or key
Transport: HTTP
Recommended access: Read and send

Before you start

Check these points before opening v0's settings. They prevent most connection failures.

A team with the "MCP server" plan feature (mcp_access); without it the server responds 403 plan_limit_reached.
To send emails, the team needs at least one verified domain.
If you will use an API key: create the key in the dashboard, under API keys. It starts with ps_; a send-only key is enough if you will only send.
Each connection acts on a single team. To use another team, connect again and pick the other one.
Connections are listed under Settings › AI connections in the dashboard, where they can be revoked at any time.

What v0 requires

v0 calls the server from its own cloud (public HTTPS; Postal is). The documentation does not state a plan, version or limits. Approval of each call depends on the chat's permission mode (Ask, Auto or Full).

Connect

Follow the steps in order. The server address is always https://api.postal.so/mcp. Recommended path: sign in with your account (OAuth). The API key is the alternative. Wherever ps_... appears, use your own API key: the value shown is only an example.

1
In v0's message box, open the + menu and choose MCPs.
2
Set up your own server: enter a name and the URL https://api.postal.so/mcp.
3
Under authentication, choose OAuth and complete the Postal sign-in (choose the team and click Allow). Alternative: Bearer Token, pasting a Postal API key (ps_...).
4
Leave the server enabled. v0 uses the tools during generation; the generated code does not call the MCP tools directly: for the app in production, use the Postal API with environment variables.

Server URL

Text

https://api.postal.so/mcp

Header (if you choose Bearer Token)

Text

Authorization: Bearer ps_...

Access the tool needs

Postal splits access into three levels, explained in the scopes table. For v0:

Required

Read your datamcp:read

View emails, domains, contacts, segments, topics, templates, broadcasts, automations, forms, inbox conversations, metrics and usage.

Recommended

Send emails and eventsmcp:send

Send and schedule emails from verified domains and record events for automations.

v0 only uses the tools during the conversation: reading domains, templates and emails (mcp:read) and sending a test email (mcp:send). There is no reason to give mcp:full to a code generator; with an API key, a sending_access key is enough for send-only.

How to confirm it worked

The simplest proof is to ask for something read-only inside v0 itself. The connection also appears under Settings › AI connections, in the Postal dashboard, with the app, the team and the last use.

Illustrative example

List my domains on Postal.

I found 2 domains on the Aurora Cosméticos team: exemplo.com.br (verified) and loja.exemplo.com.br (verifying).

For those who want the technical proof

Terminal: tool list with an API key

npx @modelcontextprotocol/inspector --cli https://api.postal.so/mcp \
  --transport http \
  --header "Authorization: Bearer ps_..." \
  --method tools/list

34Tools expected with a full-access key

The Inspector proves that the Postal server responds. It does not test v0 itself. The full walkthrough is in Validate the connection.

If something goes wrong

Go through the list in order. Then read what we know (and what we don't) about v0.

Check

The address is exactly https://api.postal.so/mcp, with /mcp at the end.
The connection type is HTTP (Streamable HTTP). Postal does not offer SSE: if the tool gives you the choice, use HTTP.
The team has the "MCP server" feature on its plan. Without it, the server responds 403 plan_limit_reached.
To send emails, the team has at least one verified domain.
Each connection acts on a single team. To use another one, connect again and pick the other.
429 response (rate_limit_exceeded): the plan's requests-per-second limit was reached. Wait a moment and try again.
If the tool complains about the response size, ask for smaller lists (at most 100 items per call; the default is 20).
To start over from scratch, revoke the connection under Settings › AI connections and connect again.

What was tested and what was not

Compatible per the specificationChecked on 10/28/2026

We followed the app's specification and documentation, but have not yet tested with the real app. Below is the full note on what was and was not verified.

Test details

v0's documentation lists OAuth, Bearer Token, headers and no authentication, but does not state the transport, the OAuth redirect URLs, plans or limits. The Bearer API key path was verified with the SDK; OAuth is the standard flow with dynamic registration (any HTTPS redirect URI is accepted), not tested with the real v0. A guide to the v0 Platform API (not official for the interface) cites https://api.v0.dev/v1/mcp-servers/oauth/callback, which Postal would also accept.

Frequently asked questions

Do I need an API key to connect v0?

It is not required. v0 can sign in with your Postal account (OAuth) or with an API key. Recommended path: sign in with your account (OAuth). The API key is the alternative. The send-only key (sending_access) exposes only send_email and track_event.

Can I limit what v0 does in my account?

Official v0 documentation Postal MCP server Authentication and keys All tools

Keep going

Other tools

Each tool has its own walkthrough. See also the full list under AI.

Ready to use Postal in v0?

Create your account and connect. If you need help, talk to us through the contact form.

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