Knowledge, or action? Take both
Skills and the MCP server solve two different problems. Skills teach the agent how our API works – the result is correct code. The MCP server gives it access to your account – the result is a message that has been sent. They complement each other and work best together.
Skills = knowledge
The agent gets precise documentation for both the JSON API v2 and the REST API v1 – including the details language models otherwise get wrong: the omnichannel flow, Unicode versus GSM, scheduling, tags and the phone number format.
It does not send anything itself. It writes the code that sends.
MCP server = action
The agent connects to your account over OAuth and gets fifteen tools: sending a message, delivery status, an overview of messages, credit, billing details, API keys and service orders.
It does not write code. It just does it.
| Aspect | Skills | MCP server |
|---|---|---|
| What it is | A documentation pack for your agent | A server your agent connects to |
| What you get | Correctly written code and an integration | An action carried out in your account |
| What you need | Nothing – installing takes no sign-in | An SmsManager account and an OAuth sign-in |
| Where it runs | Locally, inside your agent | On our server, under your account |
| Who it suits | Developers building an integration | Anyone who wants to handle messaging from a chat |
A developer usually wants both: Skills while writing the integration, the MCP server while testing it and running the account day to day.
Connecting the MCP server
The MCP server runs on the Streamable HTTP transport and authorises over OAuth 2.1. All you do in your client is paste the URL, sign in and pick a workspace – no API key is copied anywhere.
https://app-api.smsmanager.com/functions/v1/mcp
- Claude (desktop and web)
- Claude Code (CLI)
- Cursor
- Codex CLI
- ChatGPT
- In Claude's settings, add a custom connector.
- Paste our MCP server endpoint as the URL:https://app-api.smsmanager.com/functions/v1/mcp
- For authentication choose “Sign in now” – the server requires a login.
- For the OAuth client keep “Register automatically” (Dynamic Client Registration).
- Run this in your terminal:claude mcp add --transport http smsmanager https://app-api.smsmanager.com/functions/v1/mcp
- Then type /mcp in Claude Code and choose to authenticate.
- Add the server to ~/.cursor/mcp.json (available everywhere) or to .cursor/mcp.json in your project:{"mcpServers": {"smsmanager": {"url": "https://app-api.smsmanager.com/functions/v1/mcp"}}}
- In Cursor, open Customize in the sidebar and switch the server on.
- Signing in goes over OAuth. Cursor registers the client itself (Dynamic Client Registration), so there is nothing else to put in the config.
- Add the server in your terminal and sign in:codex mcp add smsmanager --url https://app-api.smsmanager.com/functions/v1/mcpcodex mcp login smsmanager
- The same thing can be written by hand into ~/.codex/config.toml:[mcp_servers.smsmanager]url = "https://app-api.smsmanager.com/functions/v1/mcp"
- In ChatGPT on the web, turn on developer mode under Settings → Apps → Advanced Settings.
- Then go to Settings → Apps, choose Create and paste our MCP server URL as the endpoint:https://app-api.smsmanager.com/functions/v1/mcp
- Pick the authentication method, click Scan Tools and finish the OAuth sign-in. ChatGPT then loads the list of tools.
Custom connectors currently work only on the ChatGPT web app and on the Business and Enterprise/Edu plans.
What happens when you connect
Three steps, with nothing to fill in or paste in between.
You sign in
You pick a workspace
The tools become available
What the MCP server can do
Fifteen tools in five groups. The agent picks the right one itself, based on what you ask for.
Identity and account status
Who you are and which workspace the connection uses, the account activation status and the concrete next step towards finishing it.
whoami, get_account_status
Sending and delivery
Sending an SMS to up to ten recipients, the status of one message, an overview of the messages sent on a given day, and received messages.
send_message, get_message_status, list_messages, list_inbox
API keys
A list of the child keys (“apps”) and the creation of a new key for a specific integration, including its permission scope.
list_apikeys, create_child_apikey
Credit and billing
The credit balance, the billing details and the bank-transfer top-up instructions – account number, IBAN and variable symbol.
get_credit, get_billing_details, set_billing_details, get_topup_details
Paid services
The catalogue of paid services with their setup and monthly fees, ordering a sender or a virtual number, and cancelling a service at the end of the paid period.
list_services, order_service, cancel_service
What you can ask the agent for
Typical scenarios an agent with the MCP server connected handles end to end.
Send it and check delivery
Top up credit by bank transfer
Order a text sender ID
Get the account activated
Prepare a key for a new integration
What the agent controls – and what it does not
- The workspace API key never reaches the model. The tools use it on our side – the agent never sees it and cannot copy it anywhere.
- Workspace membership is re-checked on every request. The moment you lose access, the connection stops working.
- An order for a paid service is a non-binding quote by default. Credit is only charged after an explicit confirmation.
- Account activation cannot be finished from a chat. Phone verification needs a browser; the tools only prepare the groundwork.
- One connection = one workspace. The agent never sees a workspace you did not pick when connecting.
Installing Skills
Skills are knowledge packs your agent loads only when it actually needs them. Pick the path that matches the agent you use.
- Claude Code (plugin)
- Skills CLI
- Manually
/plugin marketplace add smsmngr/smsmanager-skills
/plugin install smsmanager-skills@smsmanager
The Skills CLI works in Claude Code, Cursor, Codex and dozens of other agents:
npx skills add smsmngr/smsmanager-skills
You pick a specific agent with the --agent switch (-a for short):
npx skills add smsmngr/smsmanager-skills -a cursor -a codex
- Clone the repository:git clone https://github.com/smsmngr/smsmanager-skills.git
- Copy the folders from skills/ into your agent's skills directory, for example ~/.claude/skills/.
Installing takes no credentials at all. It gives your agent knowledge of our API – you only need your own API key once you want to send a real message.
Seven skills in the catalog
Catalog version 0.3.0, Apache-2.0 licence. Each skill is a short entry point that loads the details on demand.
| Skill | Category | What it does |
|---|---|---|
smsmanager-authentication | Core | API key handling, base URLs (JSON API v2 and REST API v1), the x-api-key header versus the apikey parameter, troubleshooting 401 and 403 errors. |
smsmanager-messaging-api | Messaging | Sending SMS, Viber, WhatsApp and RCS – the omnichannel flow, sender IDs and aliases, Unicode, scheduling, batches, tags and custom payloads. |
smsmanager-delivery-reports | Messaging | Webhooks for delivery reports, inbound messages and replies – the callback URL, status and rejection codes, two-way messaging. |
smsmanager-message-status | Messaging | Checking message status, listing sent messages, per-request and per-day statistics and reading the inbox through the REST API v1. |
smsmanager-optout-blacklist | Messaging | Managing the opt-out list and the blacklist – adding and removing numbers, downloading the lists as CSV. |
smsmanager-services | Account | Ordering paid services – text sender IDs, virtual numbers, SIM hosting – with a dry-run fee preview, checking credit and cancelling services. |
smsmanager-bulk-messaging | Messaging | Bulk sending from a JSONL file, validating messages without sending them, and cancelling scheduled messages and bulk uploads. |
Frequently asked questions
What is the actual difference between Skills and the MCP server?
Skills are knowledge: they teach the agent how our API works so it can write correct code. On their own they send nothing.
The MCP server is action: through it the agent signs in to your account and can work in it – send a message, verify delivery, order a sender. You can use both at once and they do not get in each other's way.
Do I have to hand my API key to the agent?
No. Installing Skills needs no credentials at all – you will need a key once you want to send a real message from your own code.
With the MCP server you sign in over OAuth. We use the workspace key on our side and never show it to the model.
Can the agent spend credit without my knowledge?
Messages that are sent are charged against your credit just as they are when sending through the API or in the app – so be as careful about what you ask the agent to send as you would be with anyone else.
Orders for paid services are stricter: the first call is always a non-binding quote and the real order only goes through after an explicit confirmation.
Does the MCP server work in clients other than Claude?
Yes. The server uses the standard Streamable HTTP transport and OAuth 2.1 authorisation, so any client that supports the MCP protocol can handle it. The instructions above cover Claude, Claude Code, Cursor, Codex CLI and a custom connector in ChatGPT – in other clients you do the same thing, you just paste the URL somewhere else.
How do I switch the connection to another workspace?
The workspace is picked once, on the consent screen, and the connection stays bound to it. If you want a different one, disconnect or revoke the app in your MCP client, connect again and choose another workspace.
How much does it cost?
Neither the MCP server nor the Skills cost anything extra. You only pay for the messages you send and the paid services you order – from the workspace credit, exactly as when sending through the API or in the app.
Are the Skills open source?
Yes, the whole catalog is public on GitHub under the Apache-2.0 licence. Read it, fork it, or write your own skill for your team based on it.
Can the agent finish activating my account?
Not all of it. It can tell you what state the activation is in and what is still missing, and it will help you draft the usage description and a sample message. Phone verification and submitting for review are finished in the browser.
Connect your agent to SmsManager
Registration is free and credit never expires. Skills install with a single command, the MCP server connects by pasting one URL – and from then on you handle messaging straight from the chat with your agent.