Codex is OpenAI's coding agent, powered by ChatGPT. ZoomInfo now ships as a Codex plugin, so a single install gives Codex the hosted ZoomInfo MCP server and 14 task-focused GTM skills at once. These are the same tools that ship with Claude and ChatGPT: search, enrichment, similar companies, intent, research. The plugin adds the workflow skills that turn those tools into finished output, like account briefs, target lists, buying-committee maps, and lead scores.
There are two ways in. Install the plugin and you get the tools and the skills together, which is what most people want. Or, if your Codex build doesn't expose plugins yet, add the MCP server by hand through the Custom MCP form. Both connect to the same endpoint and authenticate the same way.
What You Need Before You Start
A Codex account with plugin support. The plugin install path uses the Codex Plugin Directory, available in the Codex app and through /plugins in the CLI. If you don't see plugins in your build, skip to the manual Custom MCP route below.
A ZoomInfo subscription with bulk data credits. Any ZoomInfo package qualifies, but your account must have bulk data credits enabled. Recurring monthly credits are not supported by MCP. Check with your ZoomInfo admin if you're unsure. See the full requirements.
Install the Plugin
The ZoomInfo plugin bundles two things: the hosted MCP server at https://mcp.zoominfo.com/mcp, and a set of skills that tell Codex how to chain the underlying tools into a result. You install once and both arrive.
From the Codex Plugin Directory
Open the Plugin Directory
In the Codex app, open Plugins. In the CLI, run codex and then /plugins to open the plugin browser.
Find ZoomInfo
Search for ZoomInfo and open its listing.
Install
In the app, select Add to Codex. In the CLI, select Install plugin.
Connect your ZoomInfo account
Codex prompts you to sign in with ZoomInfo the first time it uses the server. Use your normal credentials or SSO. There's no developer app to register and no OAuth callback to host.
From a share link
If someone sent you a direct plugin link (the chatgpt.com/plugins/share/... form), open it and select Add to Codex. The install and the ZoomInfo sign-in work exactly as above. This is the fastest path before the listing surfaces in your directory search.
What the plugin adds
The skills are the reason to install the plugin rather than just the raw server. Each one is a prewritten workflow Codex loads when the task matches:
| Skill | What it does |
|---|---|
| Account Research | A full intelligence brief on a target account, framed by the decision you're prepping for |
| Build List | Targeted account or contact lists from natural-language criteria |
| Buying Committee | Maps decision-makers, influencers, and coverage gaps at an account |
| Score Accounts / Score Leads | Prioritizes accounts and inbound leads with explainable scoring |
| Meeting Prep | Account, attendee, and talking-point context for an upcoming call |
| Find Similar | Lookalike companies or contacts from a reference account or person |
| Enrich Company / Enrich Contact | Firmographics, financials, contact data, and accuracy signals |
| Personalize Email | Outreach grounded in intent and trigger signals |
| TAM Sizer | Market or territory sizing plus a reusable ICP filter set |
| Competitor Analysis / Tech Stack Snapshot | Fact-led competitor briefs and detected-technology summaries |
| Recommend Contacts | AI-ranked contact recommendations at a target company |
Each links to its marketplace page with what it returns. To run one explicitly, type @ in the Codex prompt and pick the skill. Otherwise describe the outcome and Codex selects the skill that fits.
Verifying the Connection Works
Try a question that needs ZoomInfo data:
How many employees does Snowflake have?or:
Look up the CEO of Datadog.If the connector is healthy, Codex calls the matching ZoomInfo tool and returns live data. The tool invocation appears inline.
For a chained smoke test:
Find 5 cybersecurity companies in New York with 200-500 employees, then find the VP of Engineering at each.That exercises Lookup, Search Companies, and Search Contacts in sequence. To confirm a skill loads, ask for one of its outputs directly:
Prep me for a meeting with Apple's VP of Marketing this afternoon.Codex should pick up the Meeting Prep skill and return a structured brief rather than a raw tool dump.
Working With Tools and Skills in Codex
Codex selects tools and skills the same way other MCP clients do: it reads the descriptions and picks what fits your request. You don't need to name anything. A few things are worth knowing in the coding-agent context.
Tool results land in your session context. Direct tools (Search, Enrich, Lookup) return data into Codex's context window. Large result sets eat context fast, so narrow your filters before running a search across thousands of records.
Research tools and skills run sub-agents. Account Research and Contact Research synthesize large payloads before returning a summary. They cost more credits per call but keep your context manageable.
Bulk credits apply the same way. Each enrichment record consumed counts against your bulk credits regardless of which client made the call.
Prefer the Manual Route? Custom MCP
If your Codex build doesn't expose plugins, or you want the server without the bundled skills, add it through the Custom MCP form. You get every tool, just not the prewritten workflows.
Open Codex Settings
From inside Codex, go to Settings, then Custom MCP.
Add a new MCP server
Click Add (or the equivalent new-entry button) and fill in:
- Name:
ZoomInfo - Transport: Streamable HTTP
- URL:
https://mcp.zoominfo.com/mcp
Save and authenticate
Click Save. Codex prompts you to sign in with ZoomInfo. Use your normal ZoomInfo credentials or SSO.
Verify the connection
Start a new Codex session and ask: "What ZoomInfo tools do you have access to?" Codex lists the tools it sees from the MCP server.
Troubleshooting
You don't see ZoomInfo in the Plugin Directory. The listing may not have reached your directory search yet. Use the share link to install directly, or fall back to the Custom MCP route above.
Codex doesn't show a Custom MCP option. Your Codex plan or workspace may not have Custom MCP enabled. Check with your OpenAI admin or workspace owner.
Authentication fails on sign-in. Confirm you're signing in with your personal ZoomInfo credentials, not a shared or admin-only account. If your ZoomInfo session has expired, the connection won't complete. Reinstall or re-add the entry if the auth state looks stale.
Codex doesn't see any ZoomInfo tools.
For the plugin, confirm it shows as installed and enabled in /plugins (press Space to toggle an installed plugin's enabled state). For Custom MCP, confirm the entry is listed and the URL is exactly https://mcp.zoominfo.com/mcp.
Credit errors on enrichment or research calls. MCP requires bulk data credits. Confirm with your ZoomInfo admin that your account has bulk credits enabled, not recurring monthly credits.
You want to turn the plugin off without uninstalling.
Toggle it in /plugins, or set its entry to enabled = false in ~/.codex/config.toml and restart Codex. Use the entry name shown in the directory.
What's Next
With ZoomInfo wired into Codex, you can pull account lists, enrich contacts, and prep deals in the same session you're writing code. For the full tool reference, see the MCP Tools documentation. For the equivalent setup in Anthropic's CLI, see How to Connect ZoomInfo to Claude Code.