> ## Documentation Index > Fetch the complete documentation index at: https://docs.melso.ai/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Melso MCP: https://mcp.melso.ai/mcp (OAuth; one company per connection). Documentation-search MCP: https://docs.melso.ai/mcp; it does not act on customer accounts. > > Use the live tool list and respect company membership. Ask the person to approve the exact invoice or tax return version in the signed-in app. Melso's professionals prepare and file included returns after approval; an AI assistant does not file. A prepared file or an approval is not evidence of filing: only the AEAT's reference and receipt are. Keep credentials out of chat and logs. # Troubleshooting connections > Fix Melso MCP connection problems: custom servers not allowed, 401 and 403, missing tools, the wrong company, transports and install links that fail. Start by asking the client: **"Read my Melso company without changing anything."** A successful [`company`](/mcp/tools/company) read shows that the connection, the OAuth grant and the company binding work. A client that shows "Connected" has not necessarily called a tool: check for a real result. ## The client cannot add a custom server Some clients limit custom MCP servers by plan, role or workspace policy. On Claude Team and Enterprise plans an Owner adds the connector for the organization. In ChatGPT, account and workspace policies decide whether **Add custom MCP server** appears. In VS Code, an organization policy can turn MCP servers off. Ask the administrator of that account or workspace; Melso cannot change it. ## Sign-in fails or tools return 401 A `401` means the client has no valid OAuth access token for `https://mcp.melso.ai/mcp`: it is missing, expired, or was issued for something else. * Start the client's sign-in again: **Connect** in Claude, `/mcp` in Claude Code, `codex mcp login melso`, `/mcp auth melso` in Gemini CLI, the Melso entry in Cursor's MCP settings, or **MCP: List Servers** in VS Code. * Remove any `Authorization` header or token you added to the configuration. Melso signs in through OAuth only, and a rejected header stops some clients from trying OAuth. * Check that the browser reached Melso's consent screen and that you approved the request there. ## Requests return 403 A `403` means the token is valid but the account cannot do this. Your membership in the company may have ended, or your role or the plan may no longer allow the tool. Reconnecting does not add permissions your Melso account lacks. Check **Configuración** in the Melso app, or ask the company's owner. ## Tools are missing A shorter list is not a failure. The server lists what the company's plan, your role and the setup allow: * Without a plan that includes the tools, only read actions are listed. * While an autónomo's setup is pending, only `company`, `fiscal_profile` and `support_tickets_create` are listed. Finish the fiscal profile, then reconnect or refresh the tool list. * `fiscal_profile` is listed for the owner or an admin. See [Permissions and approvals](/mcp/permissions). ## The assistant works in the wrong company Each connection is bound to the company chosen at consent, and a tool argument cannot switch it. Disconnect it in Melso (**Configuración**, tab **MCP**, **Desconectar**), then connect again and choose the right company. To work with two companies, add one connection for each. ## The client cannot connect * Use the exact URL `https://mcp.melso.ai/mcp`, over HTTPS, with the `/mcp` path. * Use the client's Streamable HTTP option: `--transport http` in Claude Code and Gemini CLI, `"type": "http"` in VS Code, `httpUrl` in Gemini CLI's `settings.json`. An SSE-only setting does not work. * `https://docs.melso.ai/mcp` is the documentation search server. It cannot read your records. ## An install link does not open Links that start with `cursor://` or `vscode:` need that application installed and registered to open them. Some browsers and email clients block them. Use the manual configuration on the client's page; it is equivalent. A Claude link that opens an empty dialog lost its query string: copy the full link from [Connect Claude](/mcp/claude). ## The tools changed When Melso adds or changes tools, some clients keep the old list. Refresh it: **Refresh** on the connection in ChatGPT Plugins, **MCP: Reset Cached Tools** in VS Code, reconnect from `/mcp` in Claude Code, or restart the client. ## Revoke access Open **Configuración** in the Melso app, then the **MCP** tab. **Desconectar** stops a connection at once, whatever the client still shows. Then remove the server from the client so it stops trying to connect. ## A tool returns an error A tool result with `isError: true` means the call reached Melso but did not succeed. It can be a refusal (a stale version, an action the company cannot use, a record covered by an approved return), an error while running the action, or a failure at a service Melso depends on, such as the invoicing provider. Read the message the result returns first; it describes what went wrong. Then change the request, wait and try again, or ask Melso's team. For an action that changes records, retry only the same request, as its tool page describes: for `invoices` `issue`, the same invoice and version. See [Read MCP results](/mcp/results). No tool approves, files or pays a tax return. If an assistant says it filed something, check the return in the Melso app: only the tax agency's reference and receipt prove filing. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.