Turn on developer mode in ChatGPT, add one URL, sign in with OAuth, and ChatGPT can count, search and enrich people and companies. No API key is pasted anywhere. The free plan gets the same server as Pro.
This page covers ChatGPT only. Other clients are on the MCP hub.
Before you start
You need a LeadOcean account and a ChatGPT plan that allows developer mode. Create a free LeadOcean account: no card, 1,000 records one-off, work email required.
The OpenAI developer mode docs, September 2026, list Pro, Plus, Business, Enterprise and Education accounts, on the web. A free ChatGPT account is not on that list. The page does not say whether a workspace admin must switch it on, so ask yours if the toggle is missing.
OpenAI marks developer mode as elevated risk. It gives ChatGPT full MCP client access, so only connect servers you trust.
Add the server
The server URL is https://api.leadocean.io/mcp. It speaks Streamable HTTP, which ChatGPT supports. These are the steps from OpenAI's docs:
- In ChatGPT, open Settings, then Security and login, and turn on Developer mode.
- Go to ChatGPT Plugins and select the plus button to create a developer-mode app.
- Paste
https://api.leadocean.io/mcpand choose OAuth as the authentication.
OpenAI's page does not list the form's field labels, so the exact wording may differ from step 3. LeadOcean's docs describe the same flow under Connectors, Add. The new app appears under Drafts in the app settings.
Sign in
Sign-in is OAuth 2.1 in a browser window. Save the app, choose to connect, sign in to LeadOcean, approve, and return to ChatGPT.
You do not register an OAuth client by hand. The LeadOcean OAuth server supports dynamic client registration at https://api.leadocean.io/oauth/register (scope mcp), and OpenAI says ChatGPT can use DCR when configured.
To revoke, remove the connection in ChatGPT, or remove the app under API keys, Connected apps in your LeadOcean account.
Your first prompt
Start with a count. Counting is free. In a new chat, open the Plus menu, choose Developer mode and select the LeadOcean app. Then send:
Use the LeadOcean app only. How many VP-level sales leaders in the US can I email? Count only. Do not pull anyone.
ChatGPT calls leadocean_count_leads with jobLevel set to VP, jobFunction set to Sales & Business Development and country set to US. That costs 0 records. We ran the same filters on 2026-10-01 and the tool returned 115,336, flagged exact.
That is the tool's default email filter: status verified, catch_all_valid or catch_all. It is not everyone we hold for those filters.
Naming the app and the tool follows OpenAI's own prompting advice for developer mode. When the count looks right, ask for five people with title and company. That calls leadocean_search_leads at 1 record per person, so 5. For a full sizing run, see size your TAM in ChatGPT.
The 12 tools
ChatGPT lists them as leadocean_ plus the name below. Six of them spend no records.
| Tool | What it does | Records |
|---|---|---|
leadocean_count_leads | Counts people for a filter set. | Free |
leadocean_list_filters | Lists valid filters and enum values. | Free |
leadocean_list_enum_values | Looks up exact strings, such as one of 534 industries. | Free |
leadocean_get_account | Shows plan, records left and export ceilings. | Free |
leadocean_get_export | Polls one export for status and download link. | Free |
leadocean_list_exports | Lists your exports. | Free |
leadocean_search_leads | Finds people by title, level, country, domain and more. | 1 per person returned |
leadocean_get_lead | Enriches one person by LinkedIn URL, email or person_id. | 1 |
leadocean_find_phone | Returns the phone numbers held for one person. | 1 |
leadocean_get_company | Enriches one company by domain or LinkedIn URL. | 1 |
leadocean_search_companies | Finds companies by industry, size, funding or technology. | 1 per company returned |
leadocean_export_leads | Starts a bulk CSV export of people. | 1 per row |
A leadocean_get_lead call that finds nobody costs nothing. Source: LeadOcean MCP docs, September 2026.
Troubleshooting
| Symptom | Cause | Fix |
|---|---|---|
| No Developer mode toggle | Your plan or client is not eligible, or the account is not on the web. | Use a Pro, Plus, Business, Enterprise or Education account on the web. Ask your admin on a workspace plan. |
| ChatGPT cannot reach the server | Wrong URL, or a typo in the path. | Re-enter https://api.leadocean.io/mcp exactly. |
| OAuth window closed, app stays in Drafts | You closed sign-in before approving. | Open the app in settings and connect again. |
| Tools missing or stale | ChatGPT has not pulled the tool list. | Refresh the app on its details page in the app settings. |
| ChatGPT browses the web instead | It chose a built-in tool. | Say "Use the LeadOcean app only" and name the tool. |
| 402 | Your 1,000 free records are spent, or an export needs more than you have left. | Check leadocean_get_account. Move to Pro at $499 a month, or shrink the limit. |
| 429 | Past 100 requests per second per key, or an export ceiling. | Wait a second and retry, or ask for smaller batches. |
| Wrong enum, filter rejected | A value is not in the catalogue, such as an invented industry. | Have ChatGPT call leadocean_list_enum_values and use the exact string. |
FAQ
Do I need an API key for ChatGPT?
No. The MCP server uses OAuth sign-in. The REST API uses an x-api-key header. Both spend the same records from one balance.
Is the free plan the same server as Pro?
Yes. Free is 1,000 records, one-off, with search and enrich both available. Pro is $499 a month, flat, with no per-record price.
Will ChatGPT ask me to confirm tool calls?
Possibly. OpenAI treats any tool without a readOnlyHint annotation as a write action and asks first. Expand the JSON payload, check the filters and limit, then approve.
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