Skip to main content
ChatGPT connects through the same OAuth facade as Claude — it will not accept a static API key for a remote MCP connector.

​
Add the connector

1

Open connector settings

In ChatGPT, add a custom connector (available on plans that support MCP connectors).
2

Enter the MCP URL

3

Authorize

ChatGPT discovers OnTime’s authorization server, registers itself, and sends you to sign in. Approve the organization and access level on the consent screen.
4

Test it

Use OnTime to tell me who I am.
You should get your name, organization and permissions back.
Discovery, dynamic client registration and PKCE all happen automatically — see Connect Claude for the sequence, which is identical.

​
The search and fetch pair

Alongside the ontime_* tools, OnTime exposes two bare-named tools: This pair exists because ChatGPT’s deep-research mode expects exactly these two names. It is the generic discovery path: search to find, fetch to read.
Both are read-only and gated on employee:read. Neither can change anything — writing is always through a specific ontime_* tool.
For anything specific, the dedicated tools are better. ontime_employee_search returns richer employee results than the generic search, and ontime_leave_get returns a properly typed leave request rather than a generic record. Use search/fetch when you do not know what you are looking for.

​
Access levels

The same two OAuth scopes apply:
Authorizing ontime:readwrite never grants more than you already have in the app. The scope is intersected with your employee role.

​
Interactive views

OnTime’s four interactive views are an MCP Apps feature. ChatGPT renders them as text, which is the designed fallback — the underlying data is identical.

​
Revoking access

Remove the connector in ChatGPT, or revoke the token from the OnTime admin console. Revocation in OnTime takes effect immediately.

​
Troubleshooting

The token is missing, expired or revoked. Remove and re-add the connector to re-authorize.
Your credential’s permissions are narrow, or you authorized ontime:read. Ask for ontime_whoami and compare against the tool catalog.
Either you authorized the read-only scope, or your own role does not carry the permission. The scope is intersected with your role — widening the scope will not help if the role is the limit.
More in Troubleshooting.