diff --git a/README.md b/README.md
index 47f9b5b..42c64a2 100644
--- a/README.md
+++ b/README.md
@@ -90,24 +90,24 @@ jobs:
 
 ## Inputs
 
-| Name                 | Description                                                                                                                             | Default          |
-| -------------------- | --------------------------------------------------------------------------------------------------------------------------------------- | ---------------- |
-| `openai-api-key`     | Secret used to start the Responses API proxy. Required when starting the proxy (key-only or key+prompt). Store it in `secrets`.         | `""`             |
-| `prompt`             | Inline prompt text. Provide this or `prompt-file`.                                                                                      | `""`             |
-| `prompt-file`        | Path (relative to the repository root) of a file that contains the prompt. Provide this or `prompt`.                                    | `""`             |
-| `output-file`        | File where the final Codex message is written. Leave empty to skip writing a file.                                                      | `""`             |
-| `working-directory`  | Directory passed to `codex exec --cd`. Defaults to the repository root.                                                                 | `""`             |
-| `sandbox`            | Sandbox mode for Codex. One of `workspace-write` (default), `read-only` or `danger-full-access`.                                        | `""`             |
-| `codex-version`      | Version of `@openai/codex` to install.                                                                                                  | `0.42.0-alpha.3` |
-| `codex-args`         | Extra arguments forwarded to `codex exec`. Accepts JSON arrays (`["--flag", "value"]`) or shell-style strings.                          | `""`             |
-| `output-schema`      | Inline schema contents written to a temp file and passed to `codex exec --output-schema`. Mutually exclusive with `output-schema-file`. | `""`             |
-| `output-schema-file` | Schema file forwarded to `codex exec --output-schema`. Leave empty to skip passing the option.                                          | `""`             |
-| `model`              | Model the agent should use. Leave empty to let Codex pick its default.                                                                  | `""`             |
-| `codex-home`         | Directory to use as the Codex CLI home (config/cache). Uses the CLI default when empty.                                                 | `""`             |
-| `safety-strategy`    | Controls how the action restricts Codex privileges. See [Safety strategy](#safety-strategy).                                            | `drop-sudo`      |
-| `codex-user`         | Username to run Codex as when `safety-strategy` is `unprivileged-user`.                                                                 | `""`             |
-| `allow-users`        | List of GitHub usernames who can trigger the action in addition to those who have write access to the repo.                             | ""               |
-| `allow-bots`         | Allow runs triggered by GitHub Apps/bot accounts to bypass the write-access check.                                                      | "false"          |
+| Name                 | Description                                                                                                                             | Default     |
+| -------------------- | --------------------------------------------------------------------------------------------------------------------------------------- | ----------- |
+| `openai-api-key`     | Secret used to start the Responses API proxy. Required when starting the proxy (key-only or key+prompt). Store it in `secrets`.         | `""`        |
+| `prompt`             | Inline prompt text. Provide this or `prompt-file`.                                                                                      | `""`        |
+| `prompt-file`        | Path (relative to the repository root) of a file that contains the prompt. Provide this or `prompt`.                                    | `""`        |
+| `output-file`        | File where the final Codex message is written. Leave empty to skip writing a file.                                                      | `""`        |
+| `working-directory`  | Directory passed to `codex exec --cd`. Defaults to the repository root.                                                                 | `""`        |
+| `sandbox`            | Sandbox mode for Codex. One of `workspace-write` (default), `read-only` or `danger-full-access`.                                        | `""`        |
+| `codex-version`      | Version of `@openai/codex` to install.                                                                                                  | `""`        |
+| `codex-args`         | Extra arguments forwarded to `codex exec`. Accepts JSON arrays (`["--flag", "value"]`) or shell-style strings.                          | `""`        |
+| `output-schema`      | Inline schema contents written to a temp file and passed to `codex exec --output-schema`. Mutually exclusive with `output-schema-file`. | `""`        |
+| `output-schema-file` | Schema file forwarded to `codex exec --output-schema`. Leave empty to skip passing the option.                                          | `""`        |
+| `model`              | Model the agent should use. Leave empty to let Codex pick its default.                                                                  | `""`        |
+| `codex-home`         | Directory to use as the Codex CLI home (config/cache). Uses the CLI default when empty.                                                 | `""`        |
+| `safety-strategy`    | Controls how the action restricts Codex privileges. See [Safety strategy](#safety-strategy).                                            | `drop-sudo` |
+| `codex-user`         | Username to run Codex as when `safety-strategy` is `unprivileged-user`.                                                                 | `""`        |
+| `allow-users`        | List of GitHub usernames who can trigger the action in addition to those who have write access to the repo.                             | ""          |
+| `allow-bots`         | Allow runs triggered by GitHub Apps/bot accounts to bypass the write-access check.                                                      | "false"     |
 
 ## Safety Strategy
 
diff --git a/action.yml b/action.yml
index c4d44d8..0dbe211 100644
--- a/action.yml
+++ b/action.yml
@@ -30,7 +30,7 @@ inputs:
   codex-version:
     description: "Version of `@openai/codex` to install."
     required: false
-    default: "0.45.0-alpha.4"
+    default: ""
   codex-args:
     description: "Additional args to pass through to `codex exec`. If this value starts with `[`, it will be parsed as a JSON array; otherwise, it will be parsed as a shell-like string."
     required: false