UniOne and Unisender Go MCP server
mcp-unione
An MCP server for UniOne and Unisender Go transactional email, with a send guard against accidental sends and an offline API knowledge base
Medium risk
We rate an entry medium when the tool runs code, makes network calls or reads project files. Check what exactly it does before installing.
Why this level
- Can send real mail to recipients, but only after explicit confirm_send=true
- Can delete templates, webhooks, domains and suppression list entries
Install
Manual install
uv sync && uv run mcp-unioneInstalls and runs the server over stdio from source.
This is third-party code. Review the repository files before installing.
What it does
The server wraps UniOne's transactional web API (also known as Unisender Go) with 32 typed tools across ten areas: sending mail and subscription requests, address validation, templates, webhooks, suppression lists, domain and DKIM verification, event dumps, tags and projects. It also has four documentation tools: full-text search over a bundled knowledge base of about 4000 lines of docs, fetching a live docs page, explaining a UniOne error code with its cause and fix, and explaining a delivery status. Its main safeguard: unione_send_email does not send by default, returning a preview of recipients, subject and engine instead; a real send requires the explicit confirm_send=true parameter, and sandbox=true routes the message through a test domain with no real delivery.
Who it is for. For developers setting up transactional email through UniOne or Unisender Go who want to do it safely through an agent.
Good fit when
- You want to assemble and preview an email before sending it with no risk of a real send
- You need to understand why a message did not arrive by its error code or delivery status
- You want to set up a domain, DKIM, webhooks or templates without reading UniOne's full documentation
Not a fit when
- You do not have a UniOne API key, though the docs and knowledge-base tools work even without one
- You need bulk marketing mail to large lists: the service and server are focused on transactional email
Example request
Compose a transactional order-confirmation email via UniOne and show me a preview before sendingLimitations
The project has a single author but solid engineering: semver releases, an image published to the GitHub Container Registry, and 67 tests with mocked HTTP requests. Sending without skip_unsubscribe adds an unsubscribe footer that Gmail sometimes reads as marketing and files under Promotions. The skip_unsubscribe option must first be enabled on the UniOne account itself.
How to disable. Remove the unione entry from your MCP client config or stop the Docker container.
MCP
- Transport
- stdio
- Authentication
- API key
| Environment variables | |
|---|---|
| UNIONE_API_KEY secret | UniOne API key, needed only for real calls; documentation tools work without it. |
| UNIONE_REGION | API region: eu, us or global, defaults to eu. |
Security check
- Can send real mail to recipients, but only after explicit confirm_send=true
- Can delete templates, webhooks, domains and suppression list entries
README in short
The English README describes a quick start via uv and Docker, environment variable configuration with API regions, the send guard safeguard with a detailed explanation of the unsubscribe footer and its effect on Promotions placement, tables of 32 tools across ten domains, 20 knowledge-base resources and two guided prompts, and an automated release process.
FAQ
Can the agent accidentally send an email?
No, unione_send_email without confirm_send=true only shows a preview and sends nothing, a deliberate guard against accidental sends.
Do the tools work without an API key?
Yes, knowledge-base search, docs reading and error lookups work without a key; it is only needed for real API calls.
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