Nexos for Codex and Claude Code

This public beta marketplace, nexos, offers one plugin per Nexos environment for Codex and for Claude Code:

Plugin	Connects to	Token variable
nexos	Nexos at https://nexos.ca	NEXOS_MCP_TOKEN
nexos-dev	The Nexos development service at https://dev.nexos.ca	NEXO_MCP_TOKEN

nexos is the plugin for production: it connects to the Nexos service at nexos.ca, which is open to everyone. nexos-dev connects to the development service and is meant for invited testers. Install the plugin of the environment where you have an account. The bundle contains only the plugin manifests, remote MCP configuration, skill instructions, and brand assets. It does not contain the Nexos application source code or any credential.

Installing a plugin does not grant access to a Nexos Workspace. You need a Workspace of your own (the Free plan is enough to connect) or an invitation to an existing one. Then create a personal access token in the Nexos site of that environment and store it in that plugin's token variable. A token works only in the environment that issued it.

The commands below use nexos. For the development service, use nexos-dev and NEXO_MCP_TOKEN instead.

Install the beta in Codex

Set the token variable in your user environment before you start Codex. In Windows PowerShell, this prompts for the token without echoing it or saving it in shell history:

$token = Read-Host 'Nexos token' -AsSecureString
[Environment]::SetEnvironmentVariable('NEXOS_MCP_TOKEN', [Net.NetworkCredential]::new('', $token).Password, 'User')

These commands are verified against the Codex CLI version identified in the release notes:

codex plugin marketplace add nvlsoft-ca/nexos-codex --ref main
codex plugin add nexos@nexos

Restart Codex, open a new task, invoke @nexos, and ask it to show your current Nexos user.

Install the beta in Claude Code

Set the token variable as shown above before you start Claude Code, because the plugin reads it when Claude starts. On macOS or Linux, export it from your shell profile instead. Open a new terminal, then install the plugin:

claude plugin marketplace add nvlsoft-ca/nexos-codex
claude plugin install nexos@nexos

Start Claude Code and ask it to show your current Nexos user. If claude mcp list reports plugin:nexos:nexos (or plugin:nexos-dev:nexos-dev) as failed with HTTP 401, the token is missing, expired, or revoked: create a new token in Nexos, set the variable again, and restart Claude Code.

Claude Code is the supported Claude surface in this beta. Claude.ai chat and other Claude clients are not presented as supported, because the service authenticates with the personal token header described below.

Update

In Codex:

codex plugin marketplace upgrade nexos
codex plugin add nexos@nexos

In Claude Code:

claude plugin marketplace update nexos
claude plugin update nexos@nexos

Restart the client and open a new task or session after every update.

Move from nexo@nexos

Versions up to 0.1.0-beta.4 installed one plugin named nexo for the development service. It is replaced by nexos-dev, which reads the same NEXO_MCP_TOKEN. Update the marketplace and install nexos-dev, then remove the old nexo plugin from Codex so only one development server loads:

codex plugin marketplace upgrade nexos
codex plugin add nexos-dev@nexos

In Claude Code:

claude plugin marketplace update nexos
claude plugin uninstall nexo@nexos
claude plugin install nexos-dev@nexos

Install the fixed download

The Git marketplace is the primary channel. For diagnosis or offline transfer, download the ZIP and its checksum from the Nexos site you use, for example:

• https://dev.nexos.ca/downloads/nexos-codex-latest.zip
• https://dev.nexos.ca/downloads/nexos-codex-latest.zip.sha256

Every Nexos site serves the same ZIP, which contains both plugins. Verify the checksum before extracting it, add the extracted directory as a local marketplace, and install the plugin of your environment:

codex plugin marketplace add C:\path\to\extracted\nexos-codex
codex plugin add nexos@nexos

claude plugin marketplace add C:\path\to\extracted\nexos-codex
claude plugin install nexos@nexos

Authentication boundary

nexos connects only to https://mcp.nexos.ca/mcp and reads its token only from NEXOS_MCP_TOKEN. nexos-dev connects only to https://mcp.dev.nexos.ca/mcp and reads its token only from NEXO_MCP_TOKEN. Codex reads the variable through bearer_token_env_var, and Claude Code through an Authorization: Bearer header that names the variable. Never paste a token into the plugin, a Git repository, config.toml, a Claude settings file, an Issue, or a support message. Tokens are personal, expire, and can be revoked from Nexos.

Version rollback

Git tags and GitHub releases are immutable. To reinstall a specific version in a clean marketplace configuration, use its release tag instead of main, for example:

codex plugin marketplace add nvlsoft-ca/nexos-codex --ref v0.2.0-beta.3
codex plugin add nexos@nexos

claude plugin marketplace add nvlsoft-ca/nexos-codex#v0.2.0-beta.3
claude plugin install nexos@nexos

The nexos and nexos-dev plugins start with 0.2.0-beta.2; v0.2.0-beta.1 was published without its dot-prefixed manifests and cannot be installed. Earlier tags contain only nexo; Claude Code support starts with 0.1.0-beta.4.

See RELEASE_NOTES.md for compatibility and SECURITY.md for reporting guidance.