Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsIf Codex reports “No MCP Servers Configured,” first check whether the Codex configuration contains any MCP server entries. Run codex mcp list. If the list is empty, register a local server with codex mcp add <name> -- <server-command> or a remote server with codex mcp add <name> --url <server-url>. You can also add a [mcp_servers.<name>] table to ~/.codex/config.toml. Then run the list command again and confirm that the entry appears.
The exact wording is not documented as a single, version-independent Codex error in the official pages reviewed. Treat it as a discovery or registration symptom first—not proof that a server is offline, credentials are wrong, or your network is failing.
What the message usually means
Codex has two separate states that are easy to confuse:
- Configured: Codex has an MCP server entry in the active configuration and can display it with
codex mcp list. - Working: the command or URL can start or reach the server, authenticate if required, and complete MCP requests.
“No MCP Servers Configured” points first to the configured state. An empty list means Codex has no server entry in the configuration context you are inspecting. If an entry is listed but tools still fail, you have moved past discovery and need to check that server’s own command, URL, authentication, and startup requirements.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
#1 Best Overall
OpenAI documents MCP connections for both the Codex CLI and IDE extension. Those surfaces share Codex MCP configuration, although a particular installation, user account, or version can still be pointed at a different configuration context.
Step 1: Check the active MCP configuration
- Open a terminal in the same user account that runs Codex.
- Run:
codex mcp list - Read the result. If no servers are shown, continue to registration. If your server is shown, skip to the verification and connection-diagnostics sections below.
This command checks registration; it is not a complete health check. A listed server can still fail when Codex starts it or sends a request.
Step 2: Add a local stdio server
A local stdio server is started by a command on the same machine as Codex. Put the server name before the separator and the complete startup command after it:
codex mcp add <name> -- <server-command>For example, if a server’s documentation says to start it with a command, substitute that command exactly as documented:
The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →codex mcp add my-local-server -- my-server-commandThe -- separator tells Codex that everything after it belongs to the server command and its arguments. Do not replace the command with a display label, and do not omit arguments required by that server.
Confirm the local entry
codex mcp listThe server name should now appear. If it does not, check that the add command completed without an error and that you ran both commands as the same user. A command available in one shell, virtual environment, or installation may not be available to another.
Step 3: Add a remote streamable HTTP server
For a remote MCP server, register its URL instead of a local process:
codex mcp add <name> --url <server-url>OpenAI’s documented example connects Codex to the read-only OpenAI Developer Docs MCP server:
Free tools Windows power users keep installed
One-click scans. No signup required.
codex mcp add openaiDeveloperDocs --url https://developers.openai.com/mcpcodex mcp list
After the first command, the second command verifies that the URL is registered. Registration alone does not establish that the remote service is reachable or that any required access policy is satisfied.
Step 4: Edit config.toml directly
The user-level Codex configuration file is ~/.codex/config.toml. Each server is represented by an [mcp_servers.<name>] table.
[mcp_servers.openaiDeveloperDocs]
url = "https://developers.openai.com/mcp"Save the file, then run:
codex mcp listUse either the CLI registration route or the TOML route; they describe the same configuration. Avoid creating a second, similarly named table when correcting an existing entry, because you may end up checking one name while using another.
Choose the right setup route
| Route | Configuration form | Best use | Verification |
|---|---|---|---|
| Local stdio | codex mcp add <name> -- <command> |
A server process launched on the Codex machine | codex mcp list |
| Remote streamable HTTP | codex mcp add <name> --url <url> |
A server exposed at a remote URL | codex mcp list |
| TOML | [mcp_servers.<name>] in ~/.codex/config.toml |
Manual review, repeatable configuration, or direct correction | codex mcp list |
The official configuration material establishes these routes but does not define a universal operational advantage for one server type. Follow the individual server’s documentation for its runtime and authentication requirements.
Quick wins for a faster PC:
Repair Windows errors before they cause bigger problemsFix Now →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →When the CLI lists a server but Codex still cannot use it
Check the command or URL
For a local server, run the documented startup command independently and confirm that the executable, working directory, runtime, and required arguments are available to the same user account. For a remote server, inspect the URL character-for-character and consult the provider’s documentation for access requirements.
Separate registration from startup
codex mcp list proves that Codex knows about an entry. It does not prove that a local process starts successfully or that a remote endpoint answers MCP requests. If the entry is present, stop trying to fix “missing configuration” and investigate the server’s own logs, authentication flow, and availability guidance.
Check the client context
Codex CLI and the IDE extension share MCP configuration. If the CLI shows a server but the IDE does not, verify that both are using the same Codex installation, operating-system user, and user-level configuration. The official documentation confirms shared configuration but does not enumerate every client-specific exception, so version- or installation-specific behavior must be checked in the environment where it occurs.
Re-run after every change
After editing TOML or changing a registration command, run codex mcp list again. This gives you a clear before-and-after check and avoids diagnosing a connection problem while the entry is still absent.
Recommended Free Tools
Common symptoms and fixes
| Symptom | Likely interpretation | Action |
|---|---|---|
| The list is empty | No MCP entry is present in the configuration being inspected. | Add a stdio command or remote URL, or create the correct TOML table, then list again. |
| The server name is misspelled or unexpected | The entry exists under a different name than you are checking. | Review the exact name in the add command or TOML table and use that name consistently. |
| The entry appears, but tools fail | Discovery succeeded; runtime, network, or authentication may be failing. | Use the server provider’s startup and authentication diagnostics. The configuration pages do not provide a universal failure tree. |
| CLI and IDE show different results | The surfaces may not be using the same installation or user configuration. | Compare the Codex installation, account, and ~/.codex/config.toml used by each surface. |
| A remote example was copied but nothing appears | The add command may not have run successfully, or the command was executed in another context. | Run the command again, read its output, and immediately verify with codex mcp list. |
Use the official Docs MCP example as a known configuration pattern
OpenAI’s Docs MCP page describes a read-only server for OpenAI developer documentation and shows this complete registration sequence:
codex mcp add openaiDeveloperDocs --url https://developers.openai.com/mcp
codex mcp listThe equivalent file entry is:
[mcp_servers.openaiDeveloperDocs]
url = "https://developers.openai.com/mcp"Use the example as a syntax reference, not as evidence that every third-party server has the same endpoint, permissions, or authentication behavior. The page states that Codex can connect to MCP servers in the CLI or IDE extension.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Or skip the browser setup
If your MCP project is specifically about taking website screenshots, ScreenshotNeo provides a website screenshot API and MCP server. It can accept cookie or consent banners before capture and remove more than 60 known consent platforms, newsletter popups, and chat widgets; each cleanup step can be disabled. Only clean shots are billed: bot checks or CAPTCHAs, blank pages, timeouts, failed loads, and cache hits are not billed, and each response identifies the result with X-Page-Verdict and X-Billed headers. Its MCP tools include take_screenshot, get_page_info, and capture_pdf.
One request returns an image or PDF:
curl -G "https://api.screenshotneo.com/v1/shot" -d access_key=YOUR_API_KEY --data-urlencode url=https://stripe.com -o shot.webpSee the ScreenshotNeo documentation for parameters and MCP setup. The service supports full-page and selector captures, device and viewport settings, retina scale, dark mode, PDF controls, custom CSS and JavaScript, clicks, waits, blocking rules, headers, cookies, user agents, authorization, timezone, geolocation, transparent backgrounds, resizing, chosen cache TTLs, signed image links, asynchronous webhooks, bulk requests for up to 100 URLs, usage information, and an OpenAPI specification. Common parameter names used by other screenshot APIs also work.
ScreenshotNeo’s Free plan includes 1,000 screenshots per month with no card. Paid plans start at $5 for 3,000 screenshots; every feature is available on every plan. If that fits your use case, sign up for the free plan.
Best Value
Python and Node.js equivalents for ScreenshotNeo
The same screenshot request can be made from Python:
import requests
r = requests.get("https://api.screenshotneo.com/v1/shot", params={"access_key": "YOUR_API_KEY", "url": "https://stripe.com"}, timeout=90)
open("shot.webp", "wb").write(r.content)Or Node.js:
const q = new URLSearchParams({ access_key: 'YOUR_API_KEY', url: 'https://stripe.com' });
const res = await fetch(`https://api.screenshotneo.com/v1/shot?${q}`);These calls are separate from fixing Codex registration. They are an option when the task that led you to MCP is reliable, cleaned website capture rather than general MCP server configuration.
What is and is not established about this error
The official pages establish where MCP entries live, how to add local and remote servers, how to list them, and that CLI and IDE extension configuration is shared. They do not document the exact phrase “No MCP Servers Configured” as a universal error, nor do they provide a complete diagnostic tree for process crashes, network failures, credentials, or version-specific behavior. Therefore, use the observable state—empty list versus listed entry—as your first decision point and rely on the individual server’s documentation for failures after discovery.
Frequently Asked Questions
Does an empty codex mcp list result mean Codex is broken?
No. It means no server entry is visible in the configuration context being checked. Add an entry or correct the active ~/.codex/config.toml, then verify again.
Is the OpenAI Developer Docs MCP server writable?
No. The documented example describes it as read-only access to OpenAI developer documentation.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
