Codex

Connect Praxis to Codex and drive OpenAI's terminal coding agent with your own key—editing code, running commands, answering questions. The key lives in an environment variable, never in the config file.

Every step lists its expected result: follow along yourself, or hand this page to an AI assistant that can operate your computer and let it do the install, setup, and verification for you.

What you'll accomplish

• Call Praxis models with the codex command in your terminal
• Done when: codex exec "…" returns a model reply
• Time needed: 3–5 minutes (excluding the Node.js install)
• Protocol: OpenAI Responses (Codex's native protocol)

Prerequisites

Confirm each item before you start:

• A Praxis API key (starting with sk-praxis-). If you don't have one, create it at Console → API Keys: click "Create Key"—the name is required, the validity defaults to 90 days (or pick permanent)—the dialog then shows the full key once—copy it right away. You can also re-copy the full key any time from the copy icon that appears when hovering its row in the key list. If the dialog sticks on "Creating…", refresh the list—the key exists and row copy still retrieves it in full. New accounts ship with $1 of free credit. See Quickstart for the full flow.

• Node.js 18 or newer. Check with node --version; install the LTS from nodejs.org if needed.

• Install the Codex CLI:

  npm install -g @openai/codex

  Expected: codex --version prints codex-cli <version> (this page follows 0.162.1).

Configure

Step 1: write the config file

Create ~/.codex/config.toml (on Windows, %USERPROFILE%\.codex\config.toml):

model = "deepseek-flash"
model_provider = "praxis"

[model_providers.praxis]
name = "Praxis"
base_url = "https://api.deepraxis.com/openai/v1"
env_key = "PRAXIS_API_KEY"
wire_api = "responses"

Three notes:

• The key does not go into this file—env_key declares that Codex reads it from the PRAXIS_API_KEY environment variable, set in the next step.
• wire_api must be responses: Codex speaks the OpenAI Responses protocol, not classic chat completions.
• model takes a catalog model ID; deepseek-flash is the platform's sample model—cheap, fast, good at both Chinese and English.

Expected: the next codex launch picks up the new config (restart any session already running).

Step 2: set the key environment variable

macOS / Linux (WSL included):

export PRAXIS_API_KEY=sk-praxis-your-key

Add the line to ~/.bashrc or ~/.zshrc to persist it. Windows PowerShell: $env:PRAXIS_API_KEY="your-key" (or set a system environment variable and reopen the terminal).

Expected: echo $PRAXIS_API_KEY prints your key (echo $env:PRAXIS_API_KEY on PowerShell).

Verify

From a code project directory (a git repository), run:

codex exec "Reply with exactly: connected"

Expected: the reply contains connected, ending with a tokens-used line—a reply means you're connected. The first run may print "Model metadata for … not found … Defaulting to fallback metadata"; that's the normal fallback notice for custom models and doesn't affect usage.

Drop exec and run codex for the full interactive workspace (the version banner and input box mark entry; not verified on this page).

You can also verify from the command line. Set the variable first (copying the curl verbatim without it yields a 401):

export PRAXIS_API_KEY=sk-praxis-your-key

curl https://api.deepraxis.com/openai/v1/responses \
  -H "Authorization: Bearer $PRAXIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "deepseek-flash", "input": "Hello", "max_output_tokens": 256}'

Expected: HTTP 200 means you're connected. The block in output with type text is the reply—deepseek-flash is a reasoning model, so a reasoning block may come first; that's normal.

The commands above are written for macOS / Linux / WSL (bash). On Windows PowerShell: a successful codex exec above already means you're connected—feel free to skip; for the CLI route, run $env:PRAXIS_API_KEY="your-key" first, use curl.exe (PowerShell's curl is an alias with different syntax), and join the command into a single line (dropping the trailing \).

Finally, check Console → Usage & Billing: the call you just made is already on the books—every call is billed and traceable.

FAQ

Advanced

• How much did that session cost? Console → Usage & Billing—pay per call, no idle fees
• Switch models: set model in config.toml or run codex -m <model-id>. Use deepseek-flash or deepseek-v4-flash. Codex requires a model that declares Responses support; open the model details in the model catalog and confirm Responses is listed before selecting it.
• Use it in a project: interactive codex reads files, edits code, and runs commands, asking for your confirmation before sensitive actions

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