CodexAPI

Use OpenAI's codex from python as easily as calling a function with your codex credits instead of the API.

Note: this project is not affiliated with OpenAI in any way. Thanks for the awesome tools and models though!

Requirements

• Codex CLI installed and authenticated (codex must be on your PATH).
• Python 3.8+.

Install

pip install codexapi

Quickstart

from codexapi import agent, Agent, Task

# Run one-shot tasks as a function call
print(agent("Say hello"))

# Run a multi-turn conversation as a session
session = Agent(cwd="/path/to/project")
print(session("Summarize this repo."))
print(session("Now list any risks."))

# Save and resume a session later
thread_id = session.thread_id
session2 = Agent(cwd="/path/to/project", thread_id=thread_id)
print(session2("Continue from where we left off."))

# Define a task with a checker
class RepoTask(Task):
    def check(self):
        # Return an error string if something is wrong, or None/"" if OK
        return None

task = RepoTask("Summarize this repo.", cwd="/path/to/project")
result = task()
print(result.success, result.summary)

CLI

After installing, use the codexapi command:

codexapi run "Summarize this repo."
codexapi run --cwd /path/to/project "Fix the failing tests."
echo "Say hello." | codexapi run

codexapi task exits with code 0 on success and 1 on failure.

codexapi task "Fix the failing tests." --max-iterations 5
codexapi task -f task.yaml
codexapi task -f task.yaml -i README.md

Create a new task file template:

codexapi create task.yaml
codexapi create my_task   # adds .yaml

Progress is shown by default for codexapi task; use --quiet to suppress it. When using --item, the task file must include at least one {{item}} placeholder.

Task files default to using the standard check prompt for the task. Set check: "None" to skip verification. Use max_iterations in the task file to override the default iteration cap (0 means unlimited). Checks are wrapped with the verifier prompt, include the agent output, and expect JSON with success/reason.

Take tasks from a GitHub Project (requires gh-task):

codexapi task -p owner/projects/3 -n "Your Name" -s Ready task_a.yaml task_b.yaml

Reset owned tasks on a GitHub Project back to Ready:

codexapi reset -p owner/projects/3
codexapi reset -p owner/projects/3 -d   # also removes the Progress section

Task labels are derived from task filenames (basename without extension). The issue title/body become {{item}} after removing any existing ## Progress section.

Example task progress run:

./examples/example_task_progress.sh

Show running sessions and their latest activity:

codexapi top

Press h for keys.

Resume a session and print the thread id to stderr:

codexapi run --thread-id THREAD_ID --print-thread-id "Continue where we left off."

Use --no-yolo to run Codex with --full-auto instead.

Ralph loop mode repeats the same prompt until a completion promise or a max iteration cap is hit (0 means unlimited). Cancel by deleting .codexapi/ralph-loop.local.md or running codexapi ralph --cancel. By default each iteration starts with a fresh Agent context; use --ralph-reuse to keep a single shared context across iterations.

codexapi ralph "Fix the bug." --completion-promise DONE --max-iterations 5
codexapi ralph --ralph-reuse "Try again from the same context." --max-iterations 3
codexapi ralph --cancel --cwd /path/to/project

Science mode wraps a short task in a science prompt and runs it through the Ralph loop. It defaults to --yolo and expects progress notes in SCIENCE.md. Each iteration appends the agent output to LOGBOOK.md and the runner extracts any improved figures of merit for optional notifications.

codexapi science "hyper-optimize the kernel cycles"
codexapi science --no-yolo "hyper-optimize the kernel cycles" --max-iterations 3

Optional Pushover notifications: create ~/.pushover with two non-empty lines. Line 1 is your user or group key, line 2 is the app API token. When this file exists, Science will send a notification whenever it detects a new best result, including the metric values and percent improvement. Task runs will also send a ✅/❌ notification with the task summary.

Run a task file across a list file:

codexapi foreach list.txt task.yaml
codexapi foreach list.txt task.yaml -n 4
codexapi foreach list.txt task.yaml --retry-failed
codexapi foreach list.txt task.yaml --retry-all

API

agent(prompt, cwd=None, yolo=True, flags=None) -> str

Runs a single Codex turn and returns only the agent's message. Any reasoning items are filtered out.

• prompt (str): prompt to send to Codex.
• cwd (str | PathLike | None): working directory for the Codex session.
• yolo (bool): pass --yolo to Codex when true (defaults to true).
• flags (str | None): extra CLI flags to pass to Codex.

Agent(cwd=None, yolo=True, thread_id=None, flags=None)

Creates a stateful session wrapper. Calling the instance sends the prompt into the same conversation and returns only the agent's message.

• __call__(prompt) -> str: send a prompt to Codex and return the message.
• thread_id -> str | None: expose the underlying session id once created.
• yolo (bool): pass --yolo to Codex when true (defaults to true).
• flags (str | None): extra CLI flags to pass to Codex.

task(prompt, check=None, max_iterations=10, cwd=None, yolo=True, flags=None, progress=False, set_up=None, tear_down=None, on_success=None, on_failure=None) -> str

Runs a task with checker-driven retries and returns the success summary. Raises TaskFailed when the maximum iterations are reached.

• check (str | None | False): custom check prompt, default checker, or False/"None" to skip.
• max_iterations (int): maximum number of task iterations (0 means unlimited).
• progress (bool): show a tqdm progress bar with a one-line status after each round.
• set_up/tear_down/on_success/on_failure (str | None): optional hook prompts.

task_result(prompt, check=None, max_iterations=10, cwd=None, yolo=True, flags=None, progress=False, set_up=None, tear_down=None, on_success=None, on_failure=None) -> TaskResult

Runs a task with checker-driven retries and returns a TaskResult without raising TaskFailed. Arguments mirror task() (including hooks).

Task(prompt, max_iterations=10, cwd=None, yolo=True, thread_id=None, flags=None)

Runs a Codex task with checker-driven retries. Subclass it and implement check() to return an error string when the task is incomplete, or return None/"" when the task passes. If you do not override check(), the default verifier wrapper runs with the default check prompt and includes the agent output.

• __call__(debug=False, progress=False) -> TaskResult: run the task.
• set_up(): optional setup hook.
• tear_down(): optional cleanup hook.
• check(output=None) -> str | None: return an error description or None/"". output is the last agent response.
• on_success(result): optional success hook.
• on_failure(result): optional failure hook.

TaskResult(success, summary, iterations, errors, thread_id)

Simple result object returned by Task.__call__.

• success (bool): whether the task completed successfully.
• summary (str): agent summary of what happened.
• iterations (int): how many iterations were used.
• errors (str | None): last checker error, if any.
• thread_id (str | None): Codex thread id for the session.

TaskFailed

Exception raised by task() when iterations are exhausted.

• summary (str): failure summary text.
• iterations (int | None): iterations made when the task failed.
• errors (str | None): last checker error, if any.

foreach(list_file, task_file, n=None, cwd=None, yolo=True, flags=None) -> ForeachResult

Runs a task file over a list of items, updating the list file in place.

• list_file (str | PathLike): path to the list file to process.
• task_file (str | PathLike): YAML task file (must include prompt).
• n (int | None): limit parallelism to N (default: run all items in parallel).
• cwd (str | PathLike | None): working directory for the Codex session.
• yolo (bool): pass --yolo to Codex when true (defaults to true).
• flags (str | None): extra CLI flags to pass to Codex.

ForeachResult(succeeded, failed, skipped, results)

Simple result object returned by foreach().

• succeeded (int): number of successful items.
• failed (int): number of failed items.
• skipped (int): number of items skipped (already marked in the list file).
• results (list[tuple]): (item, success, summary) entries for items that ran.

Behavior notes

• Uses codex exec --json and parses JSONL events for agent_message items.
• Automatically passes --skip-git-repo-check so it can run outside a git repo.
• Passes --yolo by default (use --no-yolo or yolo=False for --full-auto).
• Raises RuntimeError if Codex exits non-zero or returns no agent message.

Configuration

Set CODEX_BIN to point at a non-default Codex binary:

export CODEX_BIN=/path/to/codex