Connect Claude or ChatGPT to Signatoro with MCP
Add Signatoro's MCP server to Claude, Claude Code or ChatGPT: make a free email signature in chat, fetch or edit your saved one, and manage your company's people.
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Signatoro runs a hosted MCP server. Add it to Claude, Claude Code, ChatGPT or any other MCP client, and the assistant can make an email signature, give the steps to install it in a mail app, fetch and edit the signature you saved, and, for a company owner, add, update and remove the company's people.
The server address is:
https://signatoro.com/mcp
It speaks MCP over streamable HTTP. Making a signature and reading the install steps work right away. The tools that use your Signatoro account ask you to sign in the first time you call one.
Three tools work without an account, seven with one
Without signing in:
| Tool | What it does |
|---|---|
create_signature | Makes a free signature from a name plus an optional title, company, phone, email, website, LinkedIn, layout and color. Returns HTML, plain text and a link to finish it in the free generator. Nothing is saved. |
list_templates | Lists the layouts, each with what it shows and when it fits. |
get_install_steps | Returns the steps from Signatoro's install guide for a mail app, such as gmail, outlook-new or apple-mail, with the link to the full guide. |
Signed in:
| Tool | Who | What it does |
|---|---|---|
get_signature | Everyone | Returns the signature you saved on Signatoro as HTML and text, ready to append to an email. Each call counts as one API request: 50 a month on Free, unlimited on a company plan. |
update_my_signature | Everyone | Changes the fields you name in your saved signature, or creates it if you have none yet. Returns the updated signature, which counts as one API request like get_signature. A connected mailbox gets the new version. |
list_members | Company owners | Lists the company's people with their status and whether their signature is installed. |
add_member | Company owners | Invites a person by email with their name, title and phone. They get the invitation with their signature in it. |
update_member_field | Company owners | Changes a person's name, title or phone. A joined member gets their updated signature by email. |
remove_member | Company owners | Removes a person from the company. This cannot be undone, and the assistant is told to confirm with you first. |
resend_invite | Company owners | Sends an invitation again and renews it if it expired. |
Each company tool follows the rules of the company page: only an owner can use it, the plan's size limit applies, and the primary owner and the person asking always stay in the company.
In a company, the company sets the company name, website, logo, layout, color, font, review badge, booking button and footnote for everyone. get_signature and update_my_signature list those parts and who changes them: an owner gets the link to the company's page on signatoro.com, and a member is told to ask the owner. update_my_signature leaves those fields as they are and says which ones it skipped.
Connect Claude
On Claude.ai or the Claude desktop app, on a Free, Pro or Max plan (Free includes one custom connector):
- Open Customize, then Connectors.
- Click "+", then "Add custom connector".
- Paste
https://signatoro.com/mcpas the server URL and click "Add". - In a chat, click "+" at the lower left, then Connectors, and turn Signatoro on.
On a Team or Enterprise plan, an owner adds it first under Organization settings, then Connectors: click "Add", choose "Custom", then "Web", and paste the same URL. Members then open Customize, then Connectors, and click "Connect".
When a tool needs your account, Claude shows a Connect card in the chat. Sign in to Signatoro, check what the assistant asks to do, and click "Approve".
In Claude Code, run this in a terminal:
claude mcp add --transport http signatoro https://signatoro.com/mcp
Claude Code opens the Signatoro sign-in page in your browser the first time a tool needs your account.
Connect ChatGPT
ChatGPT connects to your own MCP servers in developer mode, on ChatGPT on the web. OpenAI documents the switch in two places and the labels differ by account, so if one path is missing, try the other:
- Turn on developer mode: Settings, then "Security and login", then "Developer mode". Some accounts have it under Settings, then Apps, then "Advanced settings".
- Add the server: on ChatGPT's Plugins page click the plus button, or under Settings, then Apps, click "Create". Give it the name Signatoro, paste
https://signatoro.com/mcpas the server URL, keep OAuth as the authentication, and create it. - Start a new chat and add Signatoro from the tools menu.
On a Business, Enterprise or Edu workspace, an admin turns on developer mode for the workspace first.
A prompt to start with
Use Signatoro. Make me an email signature: Maya Okafor, Head of Operations at Northwind Supply, +44 20 7946 0123, northwind.co. Show me the layouts first and use the one that suits a reply-heavy inbox. Then give me the steps to add it in Gmail.
Signed in:
Use Signatoro. Change the title in my signature to Head of Design and send me the updated version.
For an owner:
Use Signatoro. List the people in my company, then invite sam@northwind.co as Sales Lead.
Signing in and privacy
Signing in uses OAuth. The assistant sends you to Signatoro's own sign-in page, where you sign in as usual, with two-factor authentication if you set it up, and approve the connection. The assistant receives a token that works only with https://signatoro.com/mcp, lasts an hour and renews itself. Your password stays with Signatoro.
The server handles signature details and your company's people. The email you write stays between you, the assistant and your mail app. To end a connection, remove the connector in Claude or ChatGPT.
Signatoro MCP questions
What is the Signatoro MCP server URL?
The Signatoro MCP server URL is https://signatoro.com/mcp. It uses the streamable HTTP transport. Add it as a custom connector in Claude, as an app in ChatGPT developer mode, or with claude mcp add --transport http signatoro https://signatoro.com/mcp in Claude Code.
Do I need a Signatoro account to use it?
Making a signature with create_signature, listing layouts and getting install steps work without an account. Fetching your saved signature with get_signature, editing it with update_my_signature and managing a company's people need a Signatoro account, and the assistant asks you to sign in the first time.
How many times can an assistant fetch my signature?
Each get_signature call counts as one API request, the same count as the signature API. The Free plan includes 50 requests a month, and a company plan has no limit. An update_my_signature call that changes something counts as one request too, since it returns the updated signature. With the month used up, the change is still saved.
Why can't the assistant change my logo or review badge?
In a company, the logo, colors, layout, font, website, review badge and booking button come from the company, so every signature matches. The company's owner changes them on the company's page at signatoro.com. The assistant tells you which parts these are and who to ask.
Can an assistant manage my company's people?
Yes, when you own the company. After you approve the connection, the assistant can list, invite, update and remove people and resend invitations, with the same limits as the company page. These tools are for owners only.
Sources
Checked against the vendors' own documentation on 2026-09-28:
- Get started with custom connectors using remote MCP (Claude Help Center, updated 2026-08-11)
- Authentication for connectors (Claude Docs)
- Lazy authentication for MCP servers (Claude Docs)
- Connect Claude Code to tools via MCP (Claude Code Docs)
- Connect and test your plugin (OpenAI Developers)
- Developer mode and MCP apps in ChatGPT (OpenAI Help Center)
- MCP authorization, 2025-11-25 (Model Context Protocol)
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