# Connect Claude to SignWith (MCP)

> Connect SignWith to Claude, and Claude can send documents for signature, check who has signed and remind signers, right in the conversation.

Source: https://signwith.co/docs/mcp/claude · Updated 2026-10-02

The SignWith MCP server is at `https://app.signwith.co/mcp`. How you add it depends on where you use Claude. Steps checked against Claude's documentation on 1 October 2026.

## Claude Code

Claude Code connects with an API key in a header, or with OAuth sign-in.

**With an API key.** Create a key in [Settings → Developers](https://app.signwith.co/settings/api), put it in an environment variable, then run:

```bash
claude mcp add --transport http signwith https://app.signwith.co/mcp \
  --header "Authorization: Bearer $SIGNWITH_API_KEY"
```

Add `--scope user` to use SignWith in all your projects, or `--scope project` to share it with your team through the project's `.mcp.json`. In a shared `.mcp.json`, refer to the key by variable so it isn't committed:

```json
{
  "mcpServers": {
    "signwith": {
      "type": "http",
      "url": "https://app.signwith.co/mcp",
      "headers": { "Authorization": "Bearer ${SIGNWITH_API_KEY}" }
    }
  }
}
```

**With OAuth.** Add the server without a header, then run `/mcp` inside Claude Code and follow the steps in your browser to sign in to SignWith:

```bash
claude mcp add --transport http signwith https://app.signwith.co/mcp
```

**Check it works.** Run `claude mcp list`, or `/mcp` inside a session, and look for `signwith`. Then ask Claude: "Which SignWith templates do I have?"

## Claude on the web, desktop and mobile

In the Claude apps, SignWith is a custom connector. Custom connectors are available on Free (one connector), Pro, Max, Team and Enterprise plans. Set it up on the web or desktop; it then works on mobile too.

- [Add to Claude](https://claude.ai/customize/connectors?modal=add-custom-connector&connectorName=SignWith&connectorUrl=https%3A%2F%2Fapp.signwith.co%2Fmcp)

The button opens Claude's **Add custom connector** dialog with SignWith filled in; review it and click **Add**. Or add it by hand.

**Free, Pro and Max:**

1. In Claude, open **Customize → Connectors**.
2. Choose **Add custom connector**.
3. Enter `https://app.signwith.co/mcp` as the server URL, and click **Add**.
4. Click **Connect**. Claude sends you to SignWith: sign in, and choose **Full access** or **View only**.

**Team and Enterprise:** an owner first adds the connector under **Organization settings → Connectors** (**Add**, then **Custom**). Each member then finds it under **Customize → Connectors** and clicks **Connect**.

To use it in a chat, turn SignWith on from the **+** menu, under **Connectors**.

Some organizations can also add an API key as a request header on a custom connector, a Claude beta feature that isn't available to everyone. If you have it, choose **No sign-in**, add the `authorization` header, and type the value as `Bearer ` followed by your key.

## What to try

- "List my SignWith templates."
- "Send the NDA template to `grace@example.com`, with Grace Hopper as the name."
- "Has everyone signed the lease for 14 Riverside Ave?"
- "Remind the people who haven't signed yet."

Claude asks for your OK before it sends, reminds or cancels anything, unless you've chosen to always allow that tool. Each document uses credits as described in [credits and billing](https://signwith.co/docs/api/credits).

## Troubleshooting

- **401 or "unauthorized" with an API key:** check the header is exactly `Authorization: Bearer sw_...` and that the key isn't revoked or expired. See [authentication](https://signwith.co/docs/api/authentication).
- **Claude can read but not send:** the connection is View only, or the key is read-only. Reconnect with Full access, or use a full-access key.
- **"insufficient_credits":** the account is out of credits. Claude can show credit packs and a checkout link, or you can buy credits in SignWith.

All tools and access rules are on the [MCP overview](https://signwith.co/docs/mcp).