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add streamer reconnection callbacks (#186)
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* add streamer reconnection callbacks

* add reconnect args to create()

* change create to __await__
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Graeme22 authored Dec 10, 2024
1 parent b7e88e2 commit ce5ef1d
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24 changes: 24 additions & 0 deletions docs/account-streamer.rst
Original file line number Diff line number Diff line change
@@ -1,6 +1,9 @@
Account Streamer
================

Basic usage
-----------

The account streamer is used to track account-level updates, such as order fills, watchlist updates and quote alerts.
Typically, you'll want a separate task running for the account streamer, which can then notify your application about important events.

Expand Down Expand Up @@ -35,3 +38,24 @@ Probably the most important information the account streamer handles is order fi
async for order in streamer.listen(PlacedOrder):
print(order)
Retry callback
--------------

The account streamer has a special "callback" function which can be used to execute arbitrary code whenever the websocket reconnects. This is useful for re-subscribing to whatever alerts you wanted to subscribe to initially (in fact, you can probably use the same function/code you use when initializing the connection).
The callback function should look something like this:

.. code-block:: python
async def callback(streamer: AlertStreamer, arg1, arg2):
await streamer.subscribe_quote_alerts()
The requirements are that the first parameter be the `AlertStreamer` instance, and the function should be asynchronous. Other than that, you have the flexibility to decide what arguments you want to use.
This callback can then be used when creating the streamer:

.. code-block:: python
async with AlertStreamer(session, reconnect_fn=callback, reconnect_args=(arg1, arg2)) as streamer:
# ...
The reconnection uses `websockets`' exponential backoff algorithm, which can be configured through environment variables `here <https://websockets.readthedocs.io/en/14.1/reference/variables.html>`_.
25 changes: 23 additions & 2 deletions docs/data-streamer.rst
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Expand Up @@ -10,7 +10,7 @@ You can create a streamer using an active production session:
.. code-block:: python
from tastytrade import DXLinkStreamer
streamer = await DXLinkStreamer.create(session)
streamer = await DXLinkStreamer(session)
Or, you can create a streamer using an asynchronous context manager:

Expand Down Expand Up @@ -110,7 +110,7 @@ For example, we can use the streamer to create an option chain that will continu
# the `streamer_symbol` property is the symbol used by the streamer
streamer_symbols = [o.streamer_symbol for o in options]
streamer = await DXLinkStreamer.create(session)
streamer = await DXLinkStreamer(session)
# subscribe to quotes and greeks for all options on that date
await streamer.subscribe(Quote, [symbol] + streamer_symbols)
await streamer.subscribe(Greeks, streamer_symbols)
Expand Down Expand Up @@ -146,3 +146,24 @@ Now, we can access the quotes and greeks at any time, and they'll be up-to-date
print(live_prices.quotes[symbol], live_prices.greeks[symbol])
>>> Quote(eventSymbol='.SPY230721C387', eventTime=0, sequence=0, timeNanoPart=0, bidTime=1689365699000, bidExchangeCode='X', bidPrice=62.01, bidSize=50.0, askTime=1689365699000, askExchangeCode='X', askPrice=62.83, askSize=50.0) Greeks(eventSymbol='.SPY230721C387', eventTime=0, eventFlags=0, index=7255910303911641088, time=1689398266363, sequence=0, price=62.6049270064687, volatility=0.536152815048564, delta=0.971506591907638, gamma=0.001814464566110275, theta=-0.1440768557397271, rho=0.0831882577866199, vega=0.0436861878838861)

Retry callback
--------------

The data streamer has a special "callback" function which can be used to execute arbitrary code whenever the websocket reconnects. This is useful for re-subscribing to whatever events you wanted to subscribe to initially (in fact, you can probably use the same function/code you use when initializing the connection).
The callback function should look something like this:

.. code-block:: python
async def callback(streamer: DXLinkStreamer, arg1, arg2):
await streamer.subscribe(Quote, ['SPY'])
The requirements are that the first parameter be the `DXLinkStreamer` instance, and the function should be asynchronous. Other than that, you have the flexibility to decide what arguments you want to use.
This callback can then be used when creating the streamer:

.. code-block:: python
async with DXLinkStreamer(session, reconnect_fn=callback, reconnect_args=(arg1, arg2)) as streamer:
# ...
The reconnection uses `websockets`' exponential backoff algorithm, which can be configured through environment variables `here <https://websockets.readthedocs.io/en/14.1/reference/variables.html>`_.
4 changes: 2 additions & 2 deletions pyproject.toml
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Expand Up @@ -16,7 +16,7 @@ dependencies = [
"httpx>=0.27.2",
"pandas-market-calendars>=4.4.1",
"pydantic>=2.9.2",
"websockets>=14.1",
"websockets>=14.1,<15",
]

[project.urls]
Expand All @@ -29,7 +29,7 @@ dev-dependencies = [
"pytest-aio>=1.5.0",
"pytest-cov>=5.0.0",
"ruff>=0.6.9",
"pyright>=1.1.384",
"pyright>=1.1.390",
]

[tool.setuptools.package-data]
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