Tejus connects to the local Codex CLI and runs it as codex app-server. OpenAI owns authentication, account limits, models, and provider behavior; Tejus wraps the session in a durable task with terminals, browser tools, diffs, worktrees, approvals, and Git delivery.

Install

Install Codex with npm from PowerShell:

npm install -g @openai/codex

Tejus looks for the codex executable and needs Codex 0.105.0 or newer. Verify it after installation:

codex --version

Authenticate

In Tejus, open Settings → Agent providers, expand Codex under Provider tools, and click Sign in. Tejus runs codex login in a terminal window; complete the browser sign-in. You can also run it yourself:

codex login

For ChatGPT-backed access, choose Sign in with ChatGPT. Codex can also use an OpenAI API key or a custom model provider configured in its own config.toml.

Check the current state with:

codex login status

When Codex is configured to use a non-OpenAI model provider, authentication may come from that provider's environment variables instead of codex login. Tejus then skips the OpenAI login check and reports “Using a custom Codex model provider; OpenAI login check skipped.”

Verify

From a new PowerShell window:

codex --version
codex login status

Then start Codex in a disposable repository and ask it to inspect the project without making changes. Resolve CLI or account errors there before debugging Tejus.

Connect to Tejus

Enable Codex

Open Settings → Agent providers, keep Codex enabled under Provider activity, and click Refresh status. The status shows the signed-in plan, for example a ChatGPT subscription or OpenAI API Key.

Confirm the binary

Tejus uses codex from your PATH by default. Set Codex binary path (in Codex's Runtime section under Provider tools) only when you intentionally maintain another installation.

Inspect models and reasoning

Confirm that the model picker reflects the current Codex catalog and reasoning options.

Run a small task

Start with a clean repository and a bounded objective. Review the permission mode and working environment before sending the first turn.

Capabilities in Tejus

Codex sessions can expose:

Model and reasoning-effort selection
Plan mode and execution
Command, tool, and file-change events
Approval requests and user input
Session resume and reconnect behavior
Context and usage information where available
Native steering of a running turn
Codex-specific account and version health checks

Native steering lets Tejus deliver a follow-up to an active Codex turn without cancelling it first. It does not bypass Codex permissions or guarantee immediate action.

Tejus discovers Codex behavior from the installed CLI. A newer CLI may expose capabilities that an older build does not.

Permission modes

Tejus mode	Codex approval policy	Codex sandbox
Ask for approval	`untrusted`	`read-only`
Approve for me	`on-request`, reviewed automatically	`workspace-write`
Full access	`never`	`danger-full-access`

Approve for me needs Codex 0.124.0 or newer.

Default model

For a fresh selection, Tejus uses GPT-6 Astra. Its effort ladder runs Low, Medium (default), High, Extra High, Max, and Ultra. Existing saved model choices stay as they are, and actual availability still comes from your Codex CLI and account.

Questions and favorites

Codex sessions can ask non-blocking questions: answer the card while the task continues. A non-blocking card is not a reason to ignore a required approval.

The model picker supports starred model-and-effort presets. Unsupported settings are normalized to the options the provider reports.

Banked resets

When the account exposes banked reset credits, the usage panel shows Banked resets. Use reset asks for confirmation and spends one credit only after rechecking the account and limits; the five-hour or weekly limit must have 10% or less remaining. If a result is unconfirmed, Retry reset checks the same attempt rather than starting a new one.

Configuration

Codex keeps its own configuration in config.toml under its home folder: %USERPROFILE%\.codex by default, or CODEX_HOME when that variable is set. In Tejus you can also set CODEX_HOME path in Codex's Runtime section.

Changing the Codex model provider, authentication environment, sandbox rules, or approval settings can change what Tejus sees. Keep provider configuration in Codex rather than duplicating secrets in Tejus.

Multiple Codex accounts

Under Provider tools → Codex, Add account creates another Codex account. Leave its paths blank and Tejus keeps that account's sign-in in its own folder. Set a Shadow auth home to keep only the sign-in elsewhere while sharing settings and history with the default account, or a CODEX_HOME path to keep everything separate.

You can also import local Codex projects to bring existing conversations into Tejus.

Updating

Update through the installation method you used:

npm install -g @openai/codex@latest

For npm, pnpm, and Bun installs, Settings → Agent providers → Updates offers Update and runs the matching package-manager command for you. Restart Tejus after updating.

Troubleshooting

Codex is not detected

Tejus shows “Codex CLI (codex) is not installed or not on PATH.”

Run codex --version in a new PowerShell window.
Check whether multiple codex executables exist on PATH (Get-Command codex -All).
Clear or correct an obsolete custom binary path in Tejus.
Restart Tejus after installation or PATH changes.

Codex is too old

Tejus shows “Codex CLI v… is too old for Tejus. Upgrade to v0.105.0 or newer and restart Tejus.” Update Codex, verify the version in a new window, and restart Tejus.

Tejus reports that Codex is not authenticated

Tejus shows “Codex CLI is not authenticated. Run codex login and try again.” Use Sign in in Settings → Agent providers, or run codex login status and then codex login. For a custom model provider, verify its required environment variables and Codex configuration instead.

Authentication check reports `url is not supported for stdio`

This is a configuration error: the same MCP server has both HTTP and stdio settings. Tejus keeps only the HTTP settings of its own managed [mcp_servers.tejus] entry when it checks Codex or starts a session, and runs the login check from the Codex home with MCP servers disabled, so the desktop's working directory cannot add a conflicting project configuration. Your other MCP servers stay unchanged. If codex login status also fails outside Tejus, correct the conflicting transport settings in that Codex configuration.

Codex