ChatGPT's developer mode turns ChatGPT into a full Model Context Protocol (MCP) client: it can call both read and write tools on remote MCP servers, with a confirmation step before anything writes. It's available on ChatGPT Plus, Pro, Business, Enterprise, and Edu accounts on the web. LeadMarina exposes a remote MCP server at https://leadmarina.com/api/mcp (streamable HTTP), so you can run lead searches, filter results, check your balance, schedule recurring searches, and push leads to your CRM without leaving a chat.

Requirements

• A paid ChatGPT plan (Plus, Pro, Business, Enterprise, or Edu). Developer mode is not available on ChatGPT Free.
• A LeadMarina account on any plan. The MCP server and REST API are included on every plan, including the free plan (100 leads).

Connect LeadMarina

• In ChatGPT on the web, open Settings → Plugins → Developer mode and turn the toggle on. The Developer mode toggle lives under the Plugins settings and requires a paid plan.
• Still under Settings → Plugins, select the plus button to create a developer-mode app.
• Enter a name (LeadMarina), the server URL https://leadmarina.com/api/mcp, and choose OAuth authentication.
• ChatGPT registers itself automatically — LeadMarina supports OAuth 2.1 with dynamic client registration, so there is no client ID or secret to paste. Sign in to LeadMarina in the authorization window and approve access.

On Business, Enterprise, and Edu workspaces, developer mode is a workspace permission: a workspace owner (or a user granted the setting) enables it, and admins can review the connector's actions under Workspace settings → Apps, restrict it to read-only or a custom action set, and publish it for the whole workspace.

LeadMarina's server also accepts API-key headers, which other MCP clients use; in ChatGPT, OAuth is the path.

The tools

• search_leads — start a search by niche plus one city. Each search_leads call searches a single city; bulk multi-city searches (up to 250 cities in one run, within your plan's daily city budget) are a search feature of the LeadMarina web app.
• get_search_results — retrieve a search's leads; poll until enrichment is complete for the fully verified set.
• query_leads — filter leads you already own, across your whole library or inside one search — free, no balance cost.
• enrich_domains — enrich up to 10 domains per call, 1 lead per domain; returns a search_id you poll for the finished results.
• export_leads — push leads to Close, GoHighLevel, Google Sheets, or a CSV/Excel/JSON file — a whole search, or just the slice query_leads found.
• list_searches — list your searches.
• get_balance — check your remaining lead balance.
• list_views — read the saved views you built on the leads table, as filters you can reuse.
• list_integrations — check which export destinations are connected and ready.
• list_automations — see your scheduled searches: niche, cities, cadence, destination, next run, last result.
• create_automation — schedule a search to re-run on a cadence and export itself. Cities are plain strings, and every one must be found or nothing is created; every run spends leads.
• update_automation — pause or resume one.
• delete_automation — remove one for good.

Every delivered lead is fully verified: up to 3 emails SMTP-checked and labeled safe/risky/invalid, up to 3 phones with line type (mobile/landline/VoIP/toll-free) and carrier, owner name where identifiable, social profiles (Facebook, Instagram, LinkedIn, X, YouTube, TikTok, Yelp), ratings, reviews, and the full business profile. Billing is a single meter: 1 lead = 1 delivered fully verified business. Paid plans include 15,000, 65,000 or 240,000 leads per month, and Unlimited has no monthly quota at all — up to 210,000 leads a week.

Working in a conversation

Open a new chat, choose Developer mode from the plus menu in the composer, and select the LeadMarina app. OpenAI recommends naming tools explicitly, which also produces the most predictable runs:

"Use LeadMarina's search_leads tool to find plumbers in Austin. When it finishes, call get_search_results and show me leads with a safe email and a mobile phone."

ChatGPT treats tools without a readOnlyHint annotation as write actions and asks for confirmation before running them, showing the full JSON payload it is about to send. You can have it remember an approval for the rest of the conversation; new chats reset approvals. Expect a confirmation before export_leads runs — review the destination and lead count, then approve.

Because query_leads is free, a good pattern is: search once, then iterate in chat — "only leads rated 4.5+ with an owner name," "now just the ones with Instagram" — and export only the slice you want. Under the hood those slices are real filters: query_leads targets fields like email_status, phone_line_type, rating and social_instagram, each with the operators its type takes — is for a choice like email status, gte or eq for a number like rating, contains or is_not_empty for text — combined with and/or conjunctions, so ChatGPT can translate almost any plain-English cut into a precise query. A field, operator or value the tool can't use comes back as an error that names it and lists what works, so ChatGPT can correct the call. The Export page lists every field and operator. From there, ChatGPT can draft outreach with the verified fields in context: safe-labeled emails, mobile vs. landline vs. VoIP lines, owner names, review counts.

Updates and dedupe

Exports to Close and GoHighLevel, and Google Sheets exports into a spreadsheet LeadMarina created earlier, are update-in-place. Each lead is matched on a stable Google business identifier, so re-running a search and re-exporting updates existing records instead of creating duplicates — and never touches data you created. Notes, activities, custom fields, rows, and formatting are left alone; in GoHighLevel, tags are additive-only. A CSV, Excel or JSON file, or a new spreadsheet, is a fresh copy every time.

Before your first export from chat: connect Close, GoHighLevel, or Google Sheets in the LeadMarina dashboard before using those destinations from ChatGPT. CSV/Excel/JSON file exports need no setup.

• Close connects via OAuth. Exports from ChatGPT use your saved field mapping — run one manual Export → Close in the LeadMarina web app first to create it. That first web-app export opens a field-mapping dialog: native fields map to Close built-ins, and everything else maps to custom fields LeadMarina auto-creates, named after its columns. The mapping is saved and tracked by Close field ID, so renaming a field in Close doesn't break it, and every export from ChatGPT reuses it.
• Google Sheets exports go to a new spreadsheet or one LeadMarina created before. All columns export; columns you've hidden arrive hidden but still update. Row identity is kept in a hidden column.

Automation

Any search can repeat once, daily, weekly, monthly, or yearly, with any export destination, and the four automation tools (list_automations, create_automation, update_automation, delete_automation) manage those schedules from ChatGPT directly. The Automations page in the LeadMarina dashboard manages the same schedules; either way, each run delivers to the destination you chose. For pipelines outside ChatGPT, the REST API (bearer API keys) is available on every plan, including free.

Deep research

ChatGPT's deep research uses only read actions from connected apps and sources data through connectors that expose search and fetch tools. LeadMarina's connector is built for regular chats in developer mode, not as a deep research source — run searches and exports in a standard conversation.

Troubleshooting

• No Developer mode toggle — it's web-only and paid-plan-only, and the toggle lives under Settings → Plugins. On Business, Enterprise, or Edu, ask a workspace owner to enable the permission.
• ChatGPT calls the wrong tool — name the app and tool explicitly ("Use LeadMarina's export_leads tool") and tell it not to use alternatives.
• Repeated confirmation prompts — approvals persist only within a conversation; this is ChatGPT's default for write tools.
• Balance surprises — call get_balance anytime; only delivered leads count, and query_leads is always free.