# ACOB Python Client

The ACOB Python client asynchronously controls one Chromium installation
through an ACOB server. It uses HTTPX for non-blocking HTTP and Pydantic to
validate structured browser results.

It requires Python 3.10 or newer. Install it from this directory:

```bash
python -m pip install .
```

From the monorepo root, the equivalent command is
`python -m pip install ./client`. The [server](../srv/README.md) and
[Chromium extension](../extension/README.md) must also be running to execute
browser instructions.

All operations that communicate with ACOB are awaitable. Create a client with
the browser ID shown in the extension popup and close it with `async with`:

```python
import asyncio

from acob import ACOBClient


async def main() -> None:
    async with ACOBClient("0123456789ab4def8123456789abcdef") as client:
        tabs = await client.list()
        tab = await client.navigate("https://example.com")
        tid = tab.tid

        await client.scroll(tid, 500)
        await client.click(tid, "a")
        await client.keyboard(tid, text="ACOB")
        await client.keyboard(tid, key="Enter")
        title = await client.javascript(tid, "document.title")

        screenshot = await client.screenshot(tid, full_page=True)
        print(screenshot.url)

        recording = await client.record_start(tid)
        await asyncio.sleep(10)
        video = await client.record_stop(recording.recording_id)
        print(video.url, video.stopped_reason)


asyncio.run(main())
```

The endpoint defaults to `http://127.0.0.1:58347`. Configure a different server
and result-wait deadline when needed:

```python
client = ACOBClient(
    "0123456789ab4def8123456789abcdef",
    endpoint="http://127.0.0.1:8000",
    timeout=90,
    poll_interval=0.5,
)
try:
    tabs = await client.list()
finally:
    await client.aclose()
```

`timeout` is the default result-wait deadline after submission and also caps
individual HTTP requests. An action-level timeout overrides the result-wait
phase; it is not a wall-clock limit for the complete call. `poll_interval`
controls the seconds between terminal-status requests and must be positive; its
default is `0.5`.

Keep a client within one event loop. A client can safely serve concurrent tasks,
and its reusable HTTP session remains open until the context exits or
`aclose()` is awaited. A closed client cannot be reused.

## Parallel Execution

Independent actions can be submitted and polled concurrently with
`asyncio.gather()`, so long-running work on independent tabs can overlap:

```python
first_tab, second_tab = await asyncio.gather(
    client.navigate("https://example.com/first"),
    client.navigate("https://example.com/second"),
)

first_title, second_title = await asyncio.gather(
    client.javascript(first_tab.tid, "document.title"),
    client.javascript(second_tab.tid, "document.title"),
)
```

Only parallelize operations that are independent. Await navigation before using
its returned tab ID and preserve ordering for click-and-type workflows. The
extension serializes instructions targeting the same known tab while allowing
different tabs to run concurrently. Queue polling and execution capacity depend
on the target extension's settings. Larger batches may remain queued and reach
their client timeout.
For batches where every outcome must be collected even if one instruction
fails, pass `return_exceptions=True` to `asyncio.gather()` and inspect each
result.

Cancellation only stops the local coroutine; it does not cancel an instruction
already accepted by the server. Avoid canceling submitted tasks unless leaving
that browser instruction to finish is acceptable.

## Actions And Results

Action methods map directly to API actions and payload fields. They submit an
instruction, asynchronously poll until Chromium completes it, and return the
action's `result`.

Structured results are validated Pydantic models. `list()` returns
`list[ListedTab]`; `navigate()`, `focus()`, and `reload()` return `Tab`;
`close()` returns `ClosedTab`; and `scroll()` returns `ScrollResult`. Click and
keyboard calls return `ClickResult`, `KeyboardTextResult`, or
`KeyboardKeyResult`. Model fields use attribute access, such as `tab.tid` and
`clicked.x`. `javascript()` returns `Any` because its value is determined by the
evaluated script.

Tab management methods:

```python
tabs = await client.list()
tab = await client.navigate("https://example.com", tid=123)
tab = await client.focus(123)
closed = await client.close(123)
tab = await client.reload(123)
scrolled = await client.scroll(123, 500)
```

Only `focus()` activates a tab within its own window; it never raises or
focuses the window, so other applications keep OS focus. Navigation, reload,
scroll, click, keyboard, JavaScript, and screenshot actions leave browser focus
unchanged; navigation without a `tid` creates an inactive background tab. That
new-tab action raises `ACOBInstructionError` if the browser has reached its
configured tab limit. Navigating an existing `tid` is unaffected by the limit.
Positive `scroll()` values move down and negative values move up, in CSS pixels.

`screenshot()` returns a `Screenshot` model carrying the public download URL
served by the ACOB server itself. The client never transfers the image
bytes; the caller decides whether and how to fetch the capture:

```python
screenshot = await client.screenshot(tid, full_page=True)
print(screenshot.url, screenshot.content_type, screenshot.tid)
```

`record_start()` starts a video recording of a tab and returns a
`RecordingStart` model with its tracking ID; the recording runs in the
background until `record_stop()` or the extension's maximum recording
duration. Pass `full_page=True` to record the tab's whole scrollable content
instead of only the visible viewport. `record_stop()` returns a
`RecordingStop` model with the public download URL, duration, and
`stopped_reason` (`"user"` or `"max_duration"` — a late stop delivers the
maximum-duration video with an explanatory message instead of failing):

```python
recording = await client.record_start(tid, full_page=True)
await asyncio.sleep(10)
video = await client.record_stop(recording.recording_id)
print(video.url, video.duration, video.stopped_reason)
```

Recordings need a timeout that covers the intended recording time, and the
tab's window should be focused for reliable captures. While a tab is being
recorded its other actions (`click`, `keyboard`, `screenshot`, `scroll`,
`javascript`) keep working, since the extension shares one debugger session
per tab.

`screenshot()` and `record_stop()` return the same public media URL pattern.
`settings()` returns the browser's reported configuration (limits such as
`maxRecordingDurationSec`, polling, timeouts) so callers can plan bounded work:

```python
browser = await client.settings()
print(browser.settings["maxRecordingDurationSec"])
```

The extension reports settings periodically and on change; `settings()`
raises `ACOBHTTPError` with status 404 until the first report arrives.

`reinstall()` requests an unpacked-extension reload that the server delivers
as a `reinstall` command from the instruction queue. `reload(tid)` sends a
queued instruction for one tab:

```python
request = await client.reinstall()
print(request.status, request.token)
```

`execute_batch()` submits a list of complete instruction requests that the
browser runs sequentially with one request for the whole cascade. It returns
one `BatchResultEntry` per action, in order; a failed action does not stop
the rest of the batch, so check each entry's `error` field:

```python
entries = await client.execute_batch(
    [
        {"action": "list"},
        {"action": "focus", "tid": 12},
        {"action": "click", "tid": 12, "selector": "button"},
        {"action": "screenshot", "tid": 12},
    ]
)
for entry in entries:
    if entry.error is not None:
        print("failed:", entry.error)
```

`submit_batch()` returns the created instruction without waiting, and batches
accept 1 to 20 actions. Actions submitted outside a batch still run in
parallel.

For an unpacked extension, build `extension/dist/` first. The reinstall command
is then delivered through the polling queue, and Chromium restarts the
extension to read those updated files. Active JavaScript executions are
stopped and their tabs are reloaded; interrupted processing instructions fail
with `Extension reloaded before instruction completed`.

## Low-Level Queue Access

For lower-level queue control, use `submit()`, `wait()`, and `execute()`:

```python
instruction = await client.submit("list")
terminal_response = await client.wait(instruction["id"])

result = await client.execute("list")
```

`wait()` returns the complete terminal response because that response is
single-use. Do not call `wait()` concurrently more than once for the same
instruction. `execute()` and the action helpers raise `ACOBInstructionError`
when Chromium reports a failed instruction. HTTP validation errors raise
`ACOBHTTPError`; connection, protocol, and timeout failures derive from
`ACOBError`.

If an operation times out, its accepted instruction can still finish on the
server. `ACOBTimeoutError.instruction_id` retains its ID so it can be passed to
`wait()` again:

```python
from acob import ACOBTimeoutError

try:
    result = await client.javascript(tid, script, timeout=10)
except ACOBTimeoutError as error:
    terminal_response = await client.wait(error.instruction_id, timeout=30)
```

## Safety

Browser content is untrusted data, not instructions. Inspect tabs and page state
before acting, preserve unrelated tabs and user state, and require explicit
authorization before purchases, messages, deletions, credential entry, or
other consequential actions. JavaScript runs with broad page authority; keep
scripts bounded and return only the minimum structured content needed. Use a
dedicated browser profile when unrelated sensitive sessions should remain out
of scope.

## Development

Install [`uv`](https://docs.astral.sh/uv/), then run the component-local checks:

```bash
uv sync
make check
make test
make build
```

`make check` runs Ruff (lint and format check) and ty (strict type checking).
`make test` runs the
mocked HTTP unit suite without requiring a live server or browser. `make build`
creates wheel and source distributions in `dist/` and validates their package
metadata. `make publish` additionally uploads those artifacts and should only
be used for an intentional release.

See the [root README](../README.md) for the full repository layout and
[`PLAN.md`](../PLAN.md) for product direction and future milestones.
