Postman Plugin in Claude Code and Codex: How to Check and Remove

If you use the Postman desktop app alongside Claude Code or OpenAI Codex, check whether Postman added its own plugin to them. A GitHub report filed October 25, 2026 shows Postman Desktop 12.33.4 enabling a Postman plugin in both agents without a prompt, and on Codex also marking its startup hook as trusted. You can confirm it in a few minutes by opening two config files, and remove it with one command or a few manual edits.

This guide covers what was reported, which files to check, how to remove the plugin, and what is still unconfirmed. Facts were checked on November 4, 2026 against the GitHub issue, Postman’s plugin repository and coverage from The New Stack and others. Postman had not posted a public response at that time.

What Postman installed, according to the report

The report is GitHub issue #14370 on postmanlabs/postman-app-support, titled “[SEVERE] Desktop auto-installs Codex/Claude plugins; installer attempts to trust its own startup hook.” The author attached logs and config excerpts from one Mac. Their Postman log recorded an auto-existing-upgrade step at 09:34 UTC on October 24, 2026, followed by the results claude-code:installed and codex:installed.

The changes listed in the issue:

Where	What was added
~/.claude/settings.json	The plugin postman@claude-plugins-official set to enabled
~/.claude/plugins/installed_plugins.json	A record for Postman plugin version 2.0.1, user scope
~/.codex/config.toml	A [marketplaces.postman] entry pointing at Postman’s GitHub repo, [plugins."postman@postman"] with enabled = true, and a hooks.state entry with a trusted_hash for Postman’s session-start hook
~/.local/bin	A postman command-line executable with matching timestamps

The Codex plugin was version 1.1.0. Both plugins connect to Postman’s remote MCP server at mcp.postman.com.

What the startup hook does

The hook runs when an agent session starts, clears or compacts. It inserts a short text file into the agent’s context that tells it to load Postman’s postman:api-engineer skill before handling API work. In practice, that means Postman’s instructions shape how the agent answers API questions in every project, not only Postman ones.

The part that drew the most criticism is the Codex trust step. Codex normally asks before running a new hook. According to the issue and Postman’s own installer code (installer/src/hosts/codex.ts calls a function named approvePostmanHook), the installer writes that approval itself. Commenters on the issue disagree on whether the hook actually fires in current Codex builds, so treat “the hook ran on your machine” as unconfirmed until you check your own logs.

Was any data sent to Postman?

No source shows that it was. The issue author says the report does not establish data exfiltration, and The New Stack called that claim unproven. A plugin that talks to a remote MCP server can send data when the agent calls its tools, but nobody has published evidence of that happening without the user’s action. Codex users who saw repeated “Auth required” warnings at startup were seeing the Postman MCP server asking for a sign-in that never happened.

The concern for most developers is consent and control: a third-party app changed the configuration of two other tools and, on Codex, skipped a security prompt meant to protect you.

How to check if Postman added itself to Claude Code

1. Quit any running Claude Code sessions.
2. Open ~/.claude/settings.json in a text editor. On Windows the folder is %USERPROFILE%\.claude.
3. Look under enabledPlugins for postman@claude-plugins-official.
4. Open ~/.claude/plugins/installed_plugins.json and search for postman.
5. In a new Claude Code session, run /plugin and /mcp and look for Postman entries or mcp.postman.com.

If none of these mention Postman, the auto-install did not reach Claude Code on that machine.

How to check Codex

1. Quit Codex.
2. Open ~/.codex/config.toml.
3. Search for postman. The three things to look for are [marketplaces.postman], [plugins."postman@postman"] and any line under hooks.state that contains postman@postman and trusted_hash.

You can run a quick search from a terminal on macOS or Linux:

grep -n -i postman ~/.claude/settings.json ~/.claude/plugins/installed_plugins.json ~/.codex/config.toml
ls -l ~/.local/bin | grep -i postman

On Windows PowerShell:

Select-String -Path "$env:USERPROFILE\.claude\settings.json","$env:USERPROFILE\.codex\config.toml" -Pattern postman

On a Mac, the Postman log at ~/Library/Application Support/Postman/logs/main.log shows whether the install step ran. Search it for auto-existing-upgrade.

How to remove the Postman plugin

The README of Postman’s plugin repository lists a removal command (as quoted by ExplainX; we could not test it):

npx @postman/postman-plugin remove

Run it, then re-check every file above. One commenter on the issue said Postman Desktop’s own “Uninstall Postman Coding Agent Plugin” option did not remove the plugin from GitHub Copilot, so don’t assume one step cleaned everything.

To remove it by hand:

1. Copy ~/.claude/settings.json and ~/.codex/config.toml to a safe place.
2. In settings.json, delete the postman@claude-plugins-official line under enabledPlugins (watch the commas so the JSON stays valid).
3. In Claude Code, run /plugin, select the Postman plugin and uninstall it, which also clears installed_plugins.json.
4. In config.toml, delete the [marketplaces.postman] and [plugins."postman@postman"] sections and the Postman line under hooks.state.
5. Delete ~/.local/bin/postman if you didn’t install the Postman CLI yourself.
6. Start each agent and confirm that /mcp no longer lists mcp.postman.com.

If you want to keep Postman’s agent plugin, you can reinstall it deliberately from Postman’s documentation after removal. That way the hook goes through Codex’s normal approval prompt.

Stop it from coming back

Until Postman explains when the auto-install runs, assume an app update could repeat it. After each Postman Desktop update, re-run the grep command above. If you manage developer machines, add ~/.claude/settings.json and ~/.codex/config.toml to whatever file-integrity or dotfile checks you already run. Our guide to checking for the malicious Claude Code extension in Cursor covers a similar audit for editor extensions.

What is still unknown

• Scope: the detailed logs come from one Mac. Other commenters report the same behavior, including on Postman 12.35.1, but there is no independent write-up from Windows or Linux yet.
• Other agents: comments mention GitHub Copilot and Cursor configs being touched. Those reports have not been verified.
• Postman’s position: as of November 4, 2026 the issue had no reply from Postman staff, and the Postman release notes did not mention the change.

FAQ

Is Postman malware now?

No. Postman is a widely used API tool, and the plugin is Postman’s own published code. The problem is that it was installed and, on Codex, trusted without asking you.

Does this affect the Postman web app?

The reports involve the desktop app, because only a local app can write to files in your home folder.

Should I uninstall Postman Desktop?

That’s your call. Removing the plugin and checking the config files after updates is enough for most people. Teams with strict change-control rules may want to pause Postman updates until the company responds.

Do I need to rotate API keys?

There’s no evidence that keys left the machine. If the Postman MCP server was signed in and you’re unsure what the agent sent it, rotating keys for sensitive APIs is a cautious step. Our Northflank breach guide walks through rotating secrets safely.

Next step

Run the grep command now, then add it to your routine after Postman updates. If you’re also wary of copycat apps, read our guide on spotting fake ChatGPT and Claude desktop apps on GitHub.

Sources

• GitHub: postmanlabs/postman-app-support issue #14370 (opened October 25, 2026; checked November 4, 2026)
• The New Stack: A developer opened Postman. Then two AI coding agents changed without their permission. (November 3, 2026)
• Byteiota: Postman just silently installed itself into Claude Code (November 3, 2026)
• ExplainX: Postman auto-installs Codex and Claude Code plugins, what to check (November 3, 2026)
• Postman app release notes (checked November 4, 2026)