Deribit api key changes introduce:

- `get_timestamp_int`: added this is the hack, so we can aboid use the custom deribit date format.

- `get_currencies`: added so we could get all deribit's available currencies.

- `get_instruments`: for a especific expiration date, it return a list of criptofeed.Symbol.

- `get_expiration_dates`: expirations dates available for btc's option contracts .

- `get_strikes_dict`: all the strike prices for an especific expiration date.

- `aio_open_interest_feed_relay` `open_oi_feed` `maybe_open_oi_feed`: this three handles all the portal stuff and the cryptofeed callbacks for the open interest and trades, for some reason it need both to work, i need to check that out at some point.

- Also a couple of format fixes.

piker/brokers/deribit/api.py

@@ -379,6 +379,82 @@ class Client:
 
         return flat
 
+    async def get_instruments(
+        self,
+        currency: str = 'btc',
+        kind: str = 'option',
+        expired: bool = False,
+        expiry_date: str = None,
+
+    ) -> list[Symbol]:
+        """
+        Get instruments for cryptoFeed.FeedHandler.
+        """
+        params: dict[str, str] = {
+            'currency': currency.upper(),
+            'kind': kind,
+            'expired': expired,
+        }
+
+        r: JSONRPCResult = await self._json_rpc_auth_wrapper(
+            'public/get_instruments',
+            params,
+        )
+        resp = r.result
+        response_list = []
+
+        for i in range(len(resp)):
+            element = resp[i]
+            name = f'{element["instrument_name"].split("-")[1]}'
+            if not expiry_date or name == expiry_date.upper():
+                response_list.append(piker_sym_to_cb_sym(element['instrument_name']))
+
+        return response_list
+
+    async def get_expiration_dates(
+        self,
+        currency: str = 'btc',
+        kind: str = 'option',
+
+    ) ->  list[str]:
+        """
+        Get a dict with all expiration dates listed as value and currency as key.
+        """
+
+        params: dict[str, str] = {
+            'currency': currency.upper(),
+            'kind': kind,
+        }
+
+        r: JSONRPCResult = await self._json_rpc_auth_wrapper(
+            'public/get_expirations',
+            params,
+        )
+        resp = r.result
+
+        return resp[currency][kind]
+
+    def get_strikes_dict(
+        self,
+        instruments: list[Symbol],
+
+    ) -> dict[str, dict[str, Decimal | None]]:
+        """
+        Get a dict with strike prices as keys.
+        """
+
+        response: dict[str, dict[str, Decimal | None]] = {}
+
+        for i in range(len(instruments)):
+            element = instruments[i]
+            strike = f'{str(element).split('-')[1]}'
+            response[f'{strike}'] = {
+                'C': None,
+                'P': None,
+            }
+
+        return response
+
     async def submit_limit(
         self,
         symbol: str,
@@ -759,6 +835,117 @@ async def maybe_open_price_feed(
 
 
 
+async def aio_open_interest_feed_relay(
+    fh: FeedHandler,
+    instruments: list[Symbol],
+    from_trio: asyncio.Queue,
+    to_trio: trio.abc.SendChannel,
+) -> None:
+    async def _trade(
+        trade: Trade,  # cryptofeed, NOT ours from `.venues`!
+        receipt_timestamp: int,
+    ) -> None:
+        '''
+        Proxy-thru `cryptofeed.FeedHandler` "trades" to `piker`-side.
+
+        '''
+        to_trio.send_nowait(('trade', trade))
+
+	# trade and oi are user defined functions that
+	# will be called when trade and open interest updates are received
+	# data type is not dict, is an object: cryptofeed.types.OpenINterest
+    async def _oi(
+        oi: OpenInterest,
+        receipt_timestamp: int,
+    ) -> None:
+        '''
+        Proxy-thru `cryptofeed.FeedHandler` "oi" to `piker`-side.
+
+        '''
+        symbol: Symbol = str_to_cb_sym(oi.symbol)
+        piker_sym: str = cb_sym_to_deribit_inst(symbol)
+        (
+            base,
+            expiry_date,
+            strike_price,
+            option_type
+        ) = tuple(
+            piker_sym.split('-')
+        )
+        msg = {
+            'timestamp': oi.timestamp,
+            'strike_price': strike_price,
+            'option_type': option_type,
+            'open_interest': Decimal(oi.open_interest),
+        }
+        to_trio.send_nowait(('oi', msg))
+
+
+    channels = [TRADES, OPEN_INTEREST]
+    callbacks={TRADES: _trade, OPEN_INTEREST: _oi}
+
+    fh.add_feed(
+        DERIBIT,
+        channels=channels,
+        symbols=instruments,
+        callbacks=callbacks
+    )
+
+    if not fh.running:
+        fh.run(
+            start_loop=False,
+            install_signal_handlers=False
+        )
+
+    # sync with trio
+    to_trio.send_nowait(None)
+
+    # run until cancelled
+    await asyncio.sleep(float('inf'))
+
+
+@acm
+async def open_oi_feed(
+    instruments: list[Symbol],
+) -> to_asyncio.LinkedTaskChannel:
+
+    fh: FeedHandler
+    first: None
+    chan: to_asyncio.LinkedTaskChannel
+    async with (
+        maybe_open_feed_handler() as fh,
+        to_asyncio.open_channel_from(
+            partial(
+                aio_open_interest_feed_relay,
+                fh,
+                instruments,
+            )
+        ) as (first, chan)
+    ):
+        yield chan
+
+
+@acm
+async def maybe_open_oi_feed(
+    instruments: list[Symbol],
+) -> trio.abc.ReceiveStream:
+
+    # TODO: add a predicate to maybe_open_context
+    feed: to_asyncio.LinkedTaskChannel
+    async with maybe_open_context(
+        acm_func=open_oi_feed,
+        kwargs={
+            'instruments': instruments
+        },
+        key=f'{instruments[0].base}',
+
+    ) as (cache_hit, feed):
+        if cache_hit:
+            yield broadcast_receiver(feed, 10)
+        else:
+            yield feed
+
+
 # TODO, move all to `.broker` submod!
 # async def aio_order_feed_relay(
 #     fh: FeedHandler,