A GitHub issue filed in Postman’s support repository details an incident where the API client automatically installed plugins and modified configurations in unrelated coding tools after a user opened Postman on macOS.
According to the report, upon opening Postman version 12.33.4, several unwanted changes occurred across the user’s system. Postman’s own logs recorded automatic installation of Claude Code and Codex plugins through an “auto-existing-upgrade” process. The Codex global configuration was modified to enable a Postman plugin from a Git repository and register startup hooks.
The installed hooks instruct Codex to load a Postman skill before responding to “any non-trivial API engineering task” including designing, implementing, testing, monitoring, documenting, or deploying APIs. This broad instruction effectively made Postman the default workflow for general API engineering work, rather than requiring explicit user requests.
Additionally, the installer automatically approved its own hook in Codex’s trusted configuration by obtaining the hook hash and writing it to the system config without user interaction in the affected application. A remote MCP (Model Context Protocol) connection to https://mcp.postman.com/mcp was enabled, though it failed due to authentication requirements.
The installation also affected Claude Code, recording a Postman plugin version 2.0.1 with installation timestamps matching the Postman launch window. A Postman CLI was installed to the user’s local bin directory.
The reporter characterized this as a “severe consent and trust-boundary problem,” arguing that an API client should not automatically modify unrelated tools’ configurations or make itself the default workflow simply because the user opened it. The issue requests Postman halt automatic plugin installation for existing users pending explicit opt-in, remove installer-side hook self-approval, and provide a complete rollback path respecting user removal preferences without reinstallation.
Key facts
- Postman version 12.33.4 automatically installed plugins in Codex and Claude without user consent
- The installation added startup hooks instructing Codex to route broad API engineering tasks through Postman skills
- Postman’s installer automatically approved its own hooks in Codex’s trusted configuration without user interaction in that application
- A remote MCP connection to Postman was enabled but failed due to authentication requirements
- The reporter discovered the automatic installation through Postman’s own logs recording the “auto-existing-upgrade” process