diff --git a/piker/_daemon.py b/piker/_daemon.py
index 82dc848a..836ce60c 100644
--- a/piker/_daemon.py
+++ b/piker/_daemon.py
@@ -22,10 +22,10 @@ from typing import Optional, Union, Callable, Any
 from contextlib import asynccontextmanager as acm
 from collections import defaultdict
 
-from pydantic import BaseModel
+from msgspec import Struct
+import tractor
 import trio
 from trio_typing import TaskStatus
-import tractor
 
 from .log import get_logger, get_console_log
 from .brokers import get_brokermod
@@ -47,16 +47,13 @@ _root_modules = [
 ]
 
 
-class Services(BaseModel):
+class Services(Struct):
 
     actor_n: tractor._supervise.ActorNursery
     service_n: trio.Nursery
     debug_mode: bool  # tractor sub-actor debug mode flag
     service_tasks: dict[str, tuple[trio.CancelScope, tractor.Portal]] = {}
 
-    class Config:
-        arbitrary_types_allowed = True
-
     async def start_service_task(
         self,
         name: str,
diff --git a/piker/brokers/binance.py b/piker/brokers/binance.py
index e528172e..add23b18 100644
--- a/piker/brokers/binance.py
+++ b/piker/brokers/binance.py
@@ -34,13 +34,13 @@ from fuzzywuzzy import process as fuzzy
 import numpy as np
 import tractor
 from pydantic.dataclasses import dataclass
-from pydantic import BaseModel
 import wsproto
 
 from .._cacheables import open_cached_client
 from ._util import resproc, SymbolNotFound
 from ..log import get_logger, get_console_log
 from ..data import ShmArray
+from ..data.types import Struct
 from ..data._web_bs import open_autorecon_ws, NoBsWs
 
 log = get_logger(__name__)
@@ -79,12 +79,14 @@ _show_wap_in_history = False
 
 
 # https://binance-docs.github.io/apidocs/spot/en/#exchange-information
-class Pair(BaseModel):
+class Pair(Struct, frozen=True):
     symbol: str
     status: str
 
     baseAsset: str
     baseAssetPrecision: int
+    cancelReplaceAllowed: bool
+    allowTrailingStop: bool
     quoteAsset: str
     quotePrecision: int
     quoteAssetPrecision: int
@@ -287,7 +289,7 @@ async def get_client() -> Client:
 
 
 # validation type
-class AggTrade(BaseModel):
+class AggTrade(Struct):
     e: str  # Event type
     E: int  # Event time
     s: str  # Symbol
@@ -341,7 +343,9 @@ async def stream_messages(ws: NoBsWs) -> AsyncGenerator[NoBsWs, dict]:
 
         elif msg.get('e') == 'aggTrade':
 
-            # validate
+            # NOTE: this is purely for a definition, ``msgspec.Struct``
+            # does not runtime-validate until you decode/encode.
+            # see: https://jcristharif.com/msgspec/structs.html#type-validation
             msg = AggTrade(**msg)
 
             # TODO: type out and require this quote format
@@ -352,8 +356,8 @@ async def stream_messages(ws: NoBsWs) -> AsyncGenerator[NoBsWs, dict]:
                 'brokerd_ts': time.time(),
                 'ticks': [{
                     'type': 'trade',
-                    'price': msg.p,
-                    'size': msg.q,
+                    'price': float(msg.p),
+                    'size': float(msg.q),
                     'broker_ts': msg.T,
                 }],
             }
@@ -448,7 +452,7 @@ async def stream_quotes(
             d = cache[sym.upper()]
             syminfo = Pair(**d)  # validation
 
-            si = sym_infos[sym] = syminfo.dict()
+            si = sym_infos[sym] = syminfo.to_dict()
 
             # XXX: after manually inspecting the response format we
             # just directly pick out the info we need
diff --git a/piker/brokers/ib/broker.py b/piker/brokers/ib/broker.py
index b768c9a1..4737d376 100644
--- a/piker/brokers/ib/broker.py
+++ b/piker/brokers/ib/broker.py
@@ -148,7 +148,7 @@ async def handle_order_requests(
                 oid=request_msg['oid'],
                 symbol=request_msg['symbol'],
                 reason=f'No account found: `{account}` ?',
-            ).dict())
+            ))
             continue
 
         client = _accounts2clients.get(account)
@@ -161,7 +161,7 @@ async def handle_order_requests(
                 oid=request_msg['oid'],
                 symbol=request_msg['symbol'],
                 reason=f'No api client loaded for account: `{account}` ?',
-            ).dict())
+            ))
             continue
 
         if action in {'buy', 'sell'}:
@@ -188,7 +188,7 @@ async def handle_order_requests(
                     oid=request_msg['oid'],
                     symbol=request_msg['symbol'],
                     reason='Order already active?',
-                ).dict())
+                ))
 
             # deliver ack that order has been submitted to broker routing
             await ems_order_stream.send(
@@ -197,9 +197,8 @@ async def handle_order_requests(
                     oid=order.oid,
                     # broker specific request id
                     reqid=reqid,
-                    time_ns=time.time_ns(),
                     account=account,
-                ).dict()
+                )
             )
 
         elif action == 'cancel':
@@ -559,7 +558,7 @@ async def trades_dialogue(
                     cids2pps,
                     validate=True,
                 )
-                all_positions.extend(msg.dict() for msg in msgs)
+                all_positions.extend(msg for msg in msgs)
 
         if not all_positions and cids2pps:
             raise RuntimeError(
@@ -665,7 +664,7 @@ async def emit_pp_update(
             msg = msgs[0]
             break
 
-    await ems_stream.send(msg.dict())
+    await ems_stream.send(msg)
 
 
 async def deliver_trade_events(
@@ -743,7 +742,7 @@ async def deliver_trade_events(
 
                     broker_details={'name': 'ib'},
                 )
-                await ems_stream.send(msg.dict())
+                await ems_stream.send(msg)
 
             case 'fill':
 
@@ -803,7 +802,7 @@ async def deliver_trade_events(
                     broker_time=trade_entry['broker_time'],
 
                 )
-                await ems_stream.send(msg.dict())
+                await ems_stream.send(msg)
 
                 # 2 cases:
                 # - fill comes first or
@@ -879,7 +878,7 @@ async def deliver_trade_events(
                 cid, msg = pack_position(item)
                 # acctid = msg.account = accounts_def.inverse[msg.account]
                 # cuck ib and it's shitty fifo sys for pps!
-                # await ems_stream.send(msg.dict())
+                # await ems_stream.send(msg)
 
             case 'event':
 
@@ -891,7 +890,7 @@ async def deliver_trade_events(
                 # level...
                 # reqid = item.get('reqid', 0)
                 # if getattr(msg, 'reqid', 0) < -1:
-                # log.info(f"TWS triggered trade\n{pformat(msg.dict())}")
+                # log.info(f"TWS triggered trade\n{pformat(msg)}")
 
                 # msg.reqid = 'tws-' + str(-1 * reqid)
 
diff --git a/piker/brokers/kraken/broker.py b/piker/brokers/kraken/broker.py
index 4e2e02f6..588a0924 100644
--- a/piker/brokers/kraken/broker.py
+++ b/piker/brokers/kraken/broker.py
@@ -32,7 +32,6 @@ from typing import (
 )
 
 import pendulum
-from pydantic import BaseModel
 import trio
 import tractor
 import wsproto
@@ -47,6 +46,7 @@ from piker.clearing._messages import (
     BrokerdPosition,
     BrokerdStatus,
 )
+from piker.data.types import Struct
 from . import log
 from .api import (
     Client,
@@ -62,7 +62,7 @@ from .feed import (
 )
 
 
-class Trade(BaseModel):
+class Trade(Struct):
     '''
     Trade class that helps parse and validate ownTrades stream
 
@@ -110,7 +110,7 @@ async def handle_order_requests(
                         'https://github.com/pikers/piker/issues/299'
                     ),
 
-                ).dict())
+                ))
                 continue
 
             # validate
@@ -136,7 +136,7 @@ async def handle_order_requests(
                         symbol=order.symbol,
                         reason="Failed order submission",
                         broker_details=resp
-                    ).dict()
+                    )
                 )
             else:
                 # TODO: handle multiple orders (cancels?)
@@ -161,7 +161,7 @@ async def handle_order_requests(
                         # account the made the order
                         account=order.account
 
-                    ).dict()
+                    )
                 )
 
         elif action == 'cancel':
@@ -189,7 +189,7 @@ async def handle_order_requests(
                         symbol=msg.symbol,
                         reason="Failed order cancel",
                         broker_details=resp
-                    ).dict()
+                    )
                 )
 
                 if not error:
@@ -217,7 +217,7 @@ async def handle_order_requests(
                                 # cancels will eventually get cancelled
                                 reason="Order cancel is still pending?",
                                 broker_details=resp
-                            ).dict()
+                            )
                         )
 
                 else:  # order cancel success case.
@@ -230,7 +230,7 @@ async def handle_order_requests(
                             status='cancelled',
                             reason='Order cancelled',
                             broker_details={'name': 'kraken'}
-                        ).dict()
+                        )
                     )
     else:
         log.error(f'Unknown order command: {request_msg}')
@@ -330,7 +330,7 @@ async def trades_dialogue(
                     avg_price=p.be_price,
                     currency='',
                 )
-                position_msgs.append(msg.dict())
+                position_msgs.append(msg)
 
         await ctx.started(
             (position_msgs, [acc_name])
@@ -408,7 +408,7 @@ async def trades_dialogue(
                                 broker_details={'name': 'kraken'},
                                 broker_time=broker_time
                             )
-                            await ems_stream.send(fill_msg.dict())
+                            await ems_stream.send(fill_msg)
 
                             filled_msg = BrokerdStatus(
                                 reqid=reqid,
@@ -432,7 +432,7 @@ async def trades_dialogue(
                                 # https://github.com/pikers/piker/issues/296
                                 remaining=0,
                             )
-                            await ems_stream.send(filled_msg.dict())
+                            await ems_stream.send(filled_msg)
 
                         # update ledger and position tracking
                         trans = await update_ledger(acctid, trades)
@@ -469,7 +469,7 @@ async def trades_dialogue(
                                 # TODO
                                 # currency=''
                             )
-                            await ems_stream.send(pp_msg.dict())
+                            await ems_stream.send(pp_msg)
 
                     case [
                         trades_msgs,
diff --git a/piker/brokers/kraken/feed.py b/piker/brokers/kraken/feed.py
index 71b75082..e52f49aa 100644
--- a/piker/brokers/kraken/feed.py
+++ b/piker/brokers/kraken/feed.py
@@ -31,7 +31,6 @@ import time
 from fuzzywuzzy import process as fuzzy
 import numpy as np
 import pendulum
-from pydantic import BaseModel
 from trio_typing import TaskStatus
 import tractor
 import trio
@@ -45,6 +44,7 @@ from piker.brokers._util import (
 )
 from piker.log import get_console_log
 from piker.data import ShmArray
+from piker.data.types import Struct
 from piker.data._web_bs import open_autorecon_ws, NoBsWs
 from . import log
 from .api import (
@@ -54,7 +54,7 @@ from .api import (
 
 
 # https://www.kraken.com/features/api#get-tradable-pairs
-class Pair(BaseModel):
+class Pair(Struct):
     altname: str  # alternate pair name
     wsname: str  # WebSocket pair name (if available)
     aclass_base: str  # asset class of base component
@@ -316,7 +316,7 @@ async def stream_quotes(
             sym = sym.upper()
 
             si = Pair(**await client.symbol_info(sym))  # validation
-            syminfo = si.dict()
+            syminfo = si.to_dict()
             syminfo['price_tick_size'] = 1 / 10**si.pair_decimals
             syminfo['lot_tick_size'] = 1 / 10**si.lot_decimals
             syminfo['asset_type'] = 'crypto'
diff --git a/piker/clearing/_allocate.py b/piker/clearing/_allocate.py
index 336a9b25..8e51ed16 100644
--- a/piker/clearing/_allocate.py
+++ b/piker/clearing/_allocate.py
@@ -22,10 +22,9 @@ from enum import Enum
 from typing import Optional
 
 from bidict import bidict
-from pydantic import BaseModel, validator
-# from msgspec import Struct
 
 from ..data._source import Symbol
+from ..data.types import Struct
 from ..pp import Position
 
 
@@ -41,33 +40,30 @@ SizeUnit = Enum(
 )
 
 
-class Allocator(BaseModel):
-
-    class Config:
-        validate_assignment = True
-        copy_on_model_validation = False
-        arbitrary_types_allowed = True
-
-        # required to get the account validator lookup working?
-        extra = 'allow'
-        underscore_attrs_are_private = False
+class Allocator(Struct):
 
     symbol: Symbol
     account: Optional[str] = 'paper'
+
+    _size_units: bidict[str, Optional[str]] = _size_units
+
     # TODO: for enums this clearly doesn't fucking work, you can't set
     # a default at startup by passing in a `dict` but yet you can set
     # that value through assignment..for wtv cucked reason.. honestly, pure
     # unintuitive garbage.
-    size_unit: str = 'currency'
-    _size_units: dict[str, Optional[str]] = _size_units
+    _size_unit: str = 'currency'
 
-    @validator('size_unit', pre=True)
-    def maybe_lookup_key(cls, v):
-        # apply the corresponding enum key for the text "description" value
+    @property
+    def size_unit(self) -> str:
+        return self._size_unit
+
+    @size_unit.setter
+    def size_unit(self, v: str) -> Optional[str]:
         if v not in _size_units:
-            return _size_units.inverse[v]
+            v = _size_units.inverse[v]
 
         assert v in _size_units
+        self._size_unit = v
         return v
 
     # TODO: if we ever want ot support non-uniform entry-slot-proportion
@@ -262,7 +258,7 @@ def mk_allocator(
     # default allocation settings
     defaults: dict[str, float] = {
         'account': None,  # select paper by default
-        'size_unit': 'currency',
+        # 'size_unit': 'currency',
         'units_limit': 400,
         'currency_limit': 5e3,
         'slots': 4,
@@ -301,6 +297,9 @@ def mk_allocator(
         # entry step 1.0
         alloc.units_limit = alloc.slots
 
+    else:
+        alloc.size_unit = 'currency'
+
     # if the current position is already greater then the limit
     # settings, increase the limit to the current position
     if alloc.size_unit == 'currency':
diff --git a/piker/clearing/_client.py b/piker/clearing/_client.py
index 837c28bc..91cb94fa 100644
--- a/piker/clearing/_client.py
+++ b/piker/clearing/_client.py
@@ -58,11 +58,11 @@ class OrderBook:
 
     def send(
         self,
-        msg: Order,
+        msg: Order | dict,
 
     ) -> dict:
         self._sent_orders[msg.oid] = msg
-        self._to_ems.send_nowait(msg.dict())
+        self._to_ems.send_nowait(msg)
         return msg
 
     def update(
@@ -73,9 +73,8 @@ class OrderBook:
 
     ) -> dict:
         cmd = self._sent_orders[uuid]
-        msg = cmd.dict()
-        msg.update(data)
-        self._sent_orders[uuid] = Order(**msg)
+        msg = cmd.copy(update=data)
+        self._sent_orders[uuid] = msg
         self._to_ems.send_nowait(msg)
         return cmd
 
@@ -88,7 +87,7 @@ class OrderBook:
             oid=uuid,
             symbol=cmd.symbol,
         )
-        self._to_ems.send_nowait(msg.dict())
+        self._to_ems.send_nowait(msg)
 
 
 _orders: OrderBook = None
@@ -149,7 +148,7 @@ async def relay_order_cmds_from_sync_code(
     book = get_orders()
     async with book._from_order_book.subscribe() as orders_stream:
         async for cmd in orders_stream:
-            if cmd['symbol'] == symbol_key:
+            if cmd.symbol == symbol_key:
                 log.info(f'Send order cmd:\n{pformat(cmd)}')
                 # send msg over IPC / wire
                 await to_ems_stream.send(cmd)
diff --git a/piker/clearing/_ems.py b/piker/clearing/_ems.py
index 051ad30e..2b9f50cd 100644
--- a/piker/clearing/_ems.py
+++ b/piker/clearing/_ems.py
@@ -26,7 +26,6 @@ import time
 from typing import AsyncIterator, Callable
 
 from bidict import bidict
-from pydantic import BaseModel
 import trio
 from trio_typing import TaskStatus
 import tractor
@@ -34,6 +33,7 @@ import tractor
 from ..log import get_logger
 from ..data._normalize import iterticks
 from ..data.feed import Feed, maybe_open_feed
+from ..data.types import Struct
 from .._daemon import maybe_spawn_brokerd
 from . import _paper_engine as paper
 from ._messages import (
@@ -231,7 +231,7 @@ async def clear_dark_triggers(
                             price=submit_price,
                             size=cmd['size'],
                         )
-                        await brokerd_orders_stream.send(msg.dict())
+                        await brokerd_orders_stream.send(msg)
 
                         # mark this entry as having sent an order
                         # request.  the entry will be replaced once the
@@ -247,14 +247,11 @@ async def clear_dark_triggers(
 
                     msg = Status(
                         oid=oid,  # ems order id
-                        resp=resp,
                         time_ns=time.time_ns(),
-                        symbol=fqsn,
+                        resp=resp,
                         trigger_price=price,
-                        broker_details={'name': broker},
-                        cmd=cmd,  # original request message
-
-                    ).dict()
+                        brokerd_msg=cmd,
+                    )
 
                     # remove exec-condition from set
                     log.info(f'removing pred for {oid}')
@@ -303,7 +300,7 @@ class TradesRelay:
     consumers: int = 0
 
 
-class Router(BaseModel):
+class Router(Struct):
     '''
     Order router which manages and tracks per-broker dark book,
     alerts, clearing and related data feed management.
@@ -324,10 +321,6 @@ class Router(BaseModel):
     # brokername to trades-dialogues streams with ``brokerd`` actors
     relays: dict[str, TradesRelay] = {}
 
-    class Config:
-        arbitrary_types_allowed = True
-        underscore_attrs_are_private = False
-
     def get_dark_book(
         self,
         brokername: str,
@@ -581,11 +574,11 @@ async def translate_and_relay_brokerd_events(
 
         if name == 'position':
 
-            pos_msg = BrokerdPosition(**brokerd_msg).dict()
+            pos_msg = BrokerdPosition(**brokerd_msg)
 
             # XXX: this will be useful for automatic strats yah?
             # keep pps per account up to date locally in ``emsd`` mem
-            sym, broker = pos_msg['symbol'], pos_msg['broker']
+            sym, broker = pos_msg.symbol, pos_msg.broker
 
             relay.positions.setdefault(
                 # NOTE: translate to a FQSN!
@@ -676,7 +669,7 @@ async def translate_and_relay_brokerd_events(
                     entry.reqid = reqid
 
                     # tell broker to cancel immediately
-                    await brokerd_trades_stream.send(entry.dict())
+                    await brokerd_trades_stream.send(entry)
 
                 # - the order is now active and will be mirrored in
                 # our book -> registered as live flow
@@ -716,7 +709,7 @@ async def translate_and_relay_brokerd_events(
             # if 10147 in message: cancel
 
             resp = 'broker_errored'
-            broker_details = msg.dict()
+            broker_details = msg
 
             # don't relay message to order requester client
             # continue
@@ -751,7 +744,7 @@ async def translate_and_relay_brokerd_events(
                 resp = 'broker_' + msg.status
 
             # pass the BrokerdStatus msg inside the broker details field
-            broker_details = msg.dict()
+            broker_details = msg
 
         elif name in (
             'fill',
@@ -760,7 +753,7 @@ async def translate_and_relay_brokerd_events(
 
             # proxy through the "fill" result(s)
             resp = 'broker_filled'
-            broker_details = msg.dict()
+            broker_details = msg
 
             log.info(f'\nFill for {oid} cleared with:\n{pformat(resp)}')
 
@@ -778,7 +771,7 @@ async def translate_and_relay_brokerd_events(
                     time_ns=time.time_ns(),
                     broker_reqid=reqid,
                     brokerd_msg=broker_details,
-                ).dict()
+                )
             )
         except KeyError:
             log.error(
@@ -843,14 +836,14 @@ async def process_client_order_cmds(
 
                 # NOTE: cancel response will be relayed back in messages
                 # from corresponding broker
-                if reqid:
+                if reqid is not None:
 
                     # send cancel to brokerd immediately!
                     log.info(
                         f'Submitting cancel for live order {reqid}'
                     )
 
-                    await brokerd_order_stream.send(msg.dict())
+                    await brokerd_order_stream.send(msg)
 
                 else:
                     # this might be a cancel for an order that hasn't been
@@ -872,7 +865,7 @@ async def process_client_order_cmds(
                             resp='dark_cancelled',
                             oid=oid,
                             time_ns=time.time_ns(),
-                        ).dict()
+                        )
                     )
                     # de-register this client dialogue
                     router.dialogues.pop(oid)
@@ -927,7 +920,7 @@ async def process_client_order_cmds(
                 # handle relaying the ems side responses back to
                 # the client/cmd sender from this request
                 log.info(f'Sending live order to {broker}:\n{pformat(msg)}')
-                await brokerd_order_stream.send(msg.dict())
+                await brokerd_order_stream.send(msg)
 
                 # an immediate response should be ``BrokerdOrderAck``
                 # with ems order id from the ``trades_dialogue()``
@@ -1007,7 +1000,7 @@ async def process_client_order_cmds(
                         resp=resp,
                         oid=oid,
                         time_ns=time.time_ns(),
-                    ).dict()
+                    )
                 )
 
 
diff --git a/piker/clearing/_messages.py b/piker/clearing/_messages.py
index 4bb0be00..e5813c78 100644
--- a/piker/clearing/_messages.py
+++ b/piker/clearing/_messages.py
@@ -1,5 +1,5 @@
 # piker: trading gear for hackers
-# Copyright (C) Tyler Goodlet (in stewardship for piker0)
+# Copyright (C) Tyler Goodlet (in stewardship for pikers)
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as published by
@@ -15,21 +15,26 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 """
-Clearing system messagingn types and protocols.
+Clearing sub-system message and protocols.
 
 """
 from typing import Optional, Union
 
-# TODO: try out just encoding/send direction for now?
-# import msgspec
-from pydantic import BaseModel
-
 from ..data._source import Symbol
+from ..data.types import Struct
 
+
+# TODO: ``msgspec`` stuff worth paying attention to:
+# - schema evolution: https://jcristharif.com/msgspec/usage.html#schema-evolution
+# - use literals for a common msg determined by diff keys?
+#   - https://jcristharif.com/msgspec/usage.html#literal
+#   - for eg. ``BrokerdStatus``, instead just have separate messages?
+
+# --------------
 # Client -> emsd
+# --------------
 
-
-class Cancel(BaseModel):
+class Cancel(Struct):
     '''Cancel msg for removing a dark (ems triggered) or
     broker-submitted (live) trigger/order.
 
@@ -39,8 +44,10 @@ class Cancel(BaseModel):
     symbol: str
 
 
-class Order(BaseModel):
+class Order(Struct):
 
+    # TODO: use ``msgspec.Literal``
+    # https://jcristharif.com/msgspec/usage.html#literal
     action: str  # {'buy', 'sell', 'alert'}
     # internal ``emdsd`` unique "order id"
     oid: str  # uuid4
@@ -48,6 +55,9 @@ class Order(BaseModel):
     account: str  # should we set a default as '' ?
 
     price: float
+    # TODO: could we drop the ``.action`` field above and instead just
+    # use +/- values here? Would make the msg smaller at the sake of a
+    # teensie fp precision?
     size: float
     brokers: list[str]
 
@@ -59,20 +69,14 @@ class Order(BaseModel):
     # the backend broker
     exec_mode: str  # {'dark', 'live', 'paper'}
 
-    class Config:
-        # just for pre-loading a ``Symbol`` when used
-        # in the order mode staging process
-        arbitrary_types_allowed = True
-        # don't copy this model instance when used in
-        # a recursive model
-        copy_on_model_validation = False
 
+# --------------
 # Client <- emsd
+# --------------
 # update msgs from ems which relay state change info
 # from the active clearing engine.
 
-
-class Status(BaseModel):
+class Status(Struct):
 
     name: str = 'status'
     oid: str  # uuid4
@@ -95,8 +99,6 @@ class Status(BaseModel):
     # }
     resp: str  # "response", see above
 
-    # symbol: str
-
     # trigger info
     trigger_price: Optional[float] = None
     # price: float
@@ -111,10 +113,12 @@ class Status(BaseModel):
     brokerd_msg: dict = {}
 
 
+# ---------------
 # emsd -> brokerd
+# ---------------
 # requests *sent* from ems to respective backend broker daemon
 
-class BrokerdCancel(BaseModel):
+class BrokerdCancel(Struct):
 
     action: str = 'cancel'
     oid: str  # piker emsd order id
@@ -130,7 +134,7 @@ class BrokerdCancel(BaseModel):
     reqid: Optional[Union[int, str]] = None
 
 
-class BrokerdOrder(BaseModel):
+class BrokerdOrder(Struct):
 
     action: str  # {buy, sell}
     oid: str
@@ -150,11 +154,12 @@ class BrokerdOrder(BaseModel):
     size: float
 
 
+# ---------------
 # emsd <- brokerd
+# ---------------
 # requests *received* to ems from broker backend
 
-
-class BrokerdOrderAck(BaseModel):
+class BrokerdOrderAck(Struct):
     '''
     Immediate reponse to a brokerd order request providing the broker
     specific unique order id so that the EMS can associate this
@@ -172,7 +177,7 @@ class BrokerdOrderAck(BaseModel):
     account: str = ''
 
 
-class BrokerdStatus(BaseModel):
+class BrokerdStatus(Struct):
 
     name: str = 'status'
     reqid: Union[int, str]
@@ -205,7 +210,7 @@ class BrokerdStatus(BaseModel):
     }
 
 
-class BrokerdFill(BaseModel):
+class BrokerdFill(Struct):
     '''
     A single message indicating a "fill-details" event from the broker
     if avaiable.
@@ -230,7 +235,7 @@ class BrokerdFill(BaseModel):
     broker_time: float
 
 
-class BrokerdError(BaseModel):
+class BrokerdError(Struct):
     '''
     Optional error type that can be relayed to emsd for error handling.
 
@@ -249,7 +254,7 @@ class BrokerdError(BaseModel):
     broker_details: dict = {}
 
 
-class BrokerdPosition(BaseModel):
+class BrokerdPosition(Struct):
     '''Position update event from brokerd.
 
     '''
diff --git a/piker/clearing/_paper_engine.py b/piker/clearing/_paper_engine.py
index cf580876..802dcf46 100644
--- a/piker/clearing/_paper_engine.py
+++ b/piker/clearing/_paper_engine.py
@@ -117,7 +117,7 @@ class PaperBoi:
             reason='paper_trigger',
             remaining=size,
         )
-        await self.ems_trades_stream.send(msg.dict())
+        await self.ems_trades_stream.send(msg)
 
         # if we're already a clearing price simulate an immediate fill
         if (
@@ -173,7 +173,7 @@ class PaperBoi:
             broker=self.broker,
             time_ns=time.time_ns(),
         )
-        await self.ems_trades_stream.send(msg.dict())
+        await self.ems_trades_stream.send(msg)
 
     async def fake_fill(
         self,
@@ -216,7 +216,7 @@ class PaperBoi:
                 'name': self.broker + '_paper',
             },
         )
-        await self.ems_trades_stream.send(msg.dict())
+        await self.ems_trades_stream.send(msg)
 
         if order_complete:
 
@@ -240,7 +240,7 @@ class PaperBoi:
                     'name': self.broker,
                 },
             )
-            await self.ems_trades_stream.send(msg.dict())
+            await self.ems_trades_stream.send(msg)
 
         # lookup any existing position
         token = f'{symbol}.{self.broker}'
@@ -268,7 +268,7 @@ class PaperBoi:
         )
         pp_msg.size, pp_msg.avg_price = pp.lifo_update(size, price)
 
-        await self.ems_trades_stream.send(pp_msg.dict())
+        await self.ems_trades_stream.send(pp_msg)
 
 
 async def simulate_fills(
@@ -384,7 +384,7 @@ async def handle_order_requests(
                     oid=request_msg['oid'],
                     symbol=request_msg['symbol'],
                     reason=f'Paper only. No account found: `{account}` ?',
-                ).dict())
+                ))
                 continue
 
             # validate
@@ -416,7 +416,7 @@ async def handle_order_requests(
                     # broker specific request id
                     reqid=reqid,
 
-                ).dict()
+                )
             )
 
         elif action == 'cancel':
diff --git a/piker/data/_sharedmem.py b/piker/data/_sharedmem.py
index 1172fc7b..82f61e79 100644
--- a/piker/data/_sharedmem.py
+++ b/piker/data/_sharedmem.py
@@ -27,13 +27,14 @@ from multiprocessing.shared_memory import SharedMemory, _USE_POSIX
 if _USE_POSIX:
     from _posixshmem import shm_unlink
 
-import tractor
+# import msgspec
 import numpy as np
-from pydantic import BaseModel
 from numpy.lib import recfunctions as rfn
+import tractor
 
 from ..log import get_logger
 from ._source import base_iohlc_dtype
+from .types import Struct
 
 
 log = get_logger(__name__)
@@ -107,15 +108,12 @@ class SharedInt:
                 log.warning(f'Shm for {name} already unlinked?')
 
 
-class _Token(BaseModel):
+class _Token(Struct, frozen=True):
     '''
     Internal represenation of a shared memory "token"
     which can be used to key a system wide post shm entry.
 
     '''
-    class Config:
-        frozen = True
-
     shm_name: str  # this servers as a "key" value
     shm_first_index_name: str
     shm_last_index_name: str
@@ -126,17 +124,22 @@ class _Token(BaseModel):
         return np.dtype(list(map(tuple, self.dtype_descr))).descr
 
     def as_msg(self):
-        return self.dict()
+        return self.to_dict()
 
     @classmethod
     def from_msg(cls, msg: dict) -> _Token:
         if isinstance(msg, _Token):
             return msg
 
+        # TODO: native struct decoding
+        # return _token_dec.decode(msg)
+
         msg['dtype_descr'] = tuple(map(tuple, msg['dtype_descr']))
         return _Token(**msg)
 
 
+# _token_dec = msgspec.msgpack.Decoder(_Token)
+
 # TODO: this api?
 # _known_tokens = tractor.ActorVar('_shm_tokens', {})
 # _known_tokens = tractor.ContextStack('_known_tokens', )
@@ -167,7 +170,7 @@ def _make_token(
         shm_name=key,
         shm_first_index_name=key + "_first",
         shm_last_index_name=key + "_last",
-        dtype_descr=np.dtype(dtype).descr
+        dtype_descr=tuple(np.dtype(dtype).descr)
     )
 
 
diff --git a/piker/data/feed.py b/piker/data/feed.py
index 66ced72f..2795535d 100644
--- a/piker/data/feed.py
+++ b/piker/data/feed.py
@@ -42,7 +42,6 @@ from trio_typing import TaskStatus
 import trimeter
 import tractor
 from tractor.trionics import maybe_open_context
-from pydantic import BaseModel
 import pendulum
 import numpy as np
 
@@ -59,6 +58,7 @@ from ._sharedmem import (
     ShmArray,
 )
 from .ingest import get_ingestormod
+from .types import Struct
 from ._source import (
     base_iohlc_dtype,
     Symbol,
@@ -84,7 +84,7 @@ if TYPE_CHECKING:
 log = get_logger(__name__)
 
 
-class _FeedsBus(BaseModel):
+class _FeedsBus(Struct):
     '''
     Data feeds broadcaster and persistence management.
 
@@ -100,10 +100,6 @@ class _FeedsBus(BaseModel):
           a dedicated cancel scope.
 
     '''
-    class Config:
-        arbitrary_types_allowed = True
-        underscore_attrs_are_private = False
-
     brokername: str
     nursery: trio.Nursery
     feeds: dict[str, tuple[dict, dict]] = {}
diff --git a/piker/data/types.py b/piker/data/types.py
new file mode 100644
index 00000000..c6cba61d
--- /dev/null
+++ b/piker/data/types.py
@@ -0,0 +1,68 @@
+# piker: trading gear for hackers
+# Copyright (C) Guillermo Rodriguez (in stewardship for piker0)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+"""
+Built-in (extension) types.
+
+"""
+from typing import Optional
+from pprint import pformat
+
+import msgspec
+
+
+class Struct(
+    msgspec.Struct,
+
+    # https://jcristharif.com/msgspec/structs.html#tagged-unions
+    # tag='pikerstruct',
+    # tag=True,
+):
+    '''
+    A "human friendlier" (aka repl buddy) struct subtype.
+
+    '''
+    def to_dict(self) -> dict:
+        return {
+            f: getattr(self, f)
+            for f in self.__struct_fields__
+        }
+
+    def __repr__(self):
+        return f'Struct({pformat(self.to_dict())})'
+
+    def copy(
+        self,
+        update: Optional[dict] = None,
+
+    ) -> msgspec.Struct:
+        '''
+        Validate-typecast all self defined fields, return a copy of us
+        with all such fields.
+
+        This is kinda like the default behaviour in `pydantic.BaseModel`.
+
+        '''
+        if update:
+            for k, v in update.items():
+                setattr(self, k, v)
+
+        # roundtrip serialize to validate
+        return msgspec.msgpack.Decoder(
+            type=type(self)
+        ).decode(
+            msgspec.msgpack.Encoder().encode(self)
+        )
diff --git a/piker/ui/_event.py b/piker/ui/_event.py
index f9982843..9c006dc8 100644
--- a/piker/ui/_event.py
+++ b/piker/ui/_event.py
@@ -21,7 +21,6 @@ Qt event proxying and processing using ``trio`` mem chans.
 from contextlib import asynccontextmanager, AsyncExitStack
 from typing import Callable
 
-from pydantic import BaseModel
 import trio
 from PyQt5 import QtCore
 from PyQt5.QtCore import QEvent, pyqtBoundSignal
@@ -30,6 +29,8 @@ from PyQt5.QtWidgets import (
     QGraphicsSceneMouseEvent as gs_mouse,
 )
 
+from ..data.types import Struct
+
 
 MOUSE_EVENTS = {
     gs_mouse.GraphicsSceneMousePress,
@@ -43,13 +44,10 @@ MOUSE_EVENTS = {
 # TODO: maybe consider some constrained ints down the road?
 # https://pydantic-docs.helpmanual.io/usage/types/#constrained-types
 
-class KeyboardMsg(BaseModel):
+class KeyboardMsg(Struct):
     '''Unpacked Qt keyboard event data.
 
     '''
-    class Config:
-        arbitrary_types_allowed = True
-
     event: QEvent
     etype: int
     key: int
@@ -57,16 +55,13 @@ class KeyboardMsg(BaseModel):
     txt: str
 
     def to_tuple(self) -> tuple:
-        return tuple(self.dict().values())
+        return tuple(self.to_dict().values())
 
 
-class MouseMsg(BaseModel):
+class MouseMsg(Struct):
     '''Unpacked Qt keyboard event data.
 
     '''
-    class Config:
-        arbitrary_types_allowed = True
-
     event: QEvent
     etype: int
     button: int
diff --git a/piker/ui/_forms.py b/piker/ui/_forms.py
index c6d09594..f62363f3 100644
--- a/piker/ui/_forms.py
+++ b/piker/ui/_forms.py
@@ -619,7 +619,7 @@ class FillStatusBar(QProgressBar):
         # color: #19232D;
         # width: 10px;
 
-        self.setRange(0, slots)
+        self.setRange(0, int(slots))
         self.setValue(value)
 
 
diff --git a/piker/ui/_orm.py b/piker/ui/_orm.py
index 67050e95..8dea0b6d 100644
--- a/piker/ui/_orm.py
+++ b/piker/ui/_orm.py
@@ -22,12 +22,9 @@ from __future__ import annotations
 from typing import (
     Optional, Generic,
     TypeVar, Callable,
-    Literal,
 )
-import enum
-import sys
 
-from pydantic import BaseModel, validator
+# from pydantic import BaseModel, validator
 from pydantic.generics import GenericModel
 from PyQt5.QtWidgets import (
     QWidget,
@@ -38,6 +35,7 @@ from ._forms import (
     # FontScaledDelegate,
     Edit,
 )
+from ..data.types import Struct
 
 
 DataType = TypeVar('DataType')
@@ -62,7 +60,7 @@ class Selection(Field[DataType], Generic[DataType]):
     options: dict[str, DataType]
     # value: DataType = None
 
-    @validator('value')  # , always=True)
+    # @validator('value')  # , always=True)
     def set_value_first(
         cls,
 
@@ -100,7 +98,7 @@ class Edit(Field[DataType], Generic[DataType]):
     widget_factory = Edit
 
 
-class AllocatorPane(BaseModel):
+class AllocatorPane(Struct):
 
     account = Selection[str](
         options=dict.fromkeys(
diff --git a/piker/ui/order_mode.py b/piker/ui/order_mode.py
index e9ed3499..83a0ed48 100644
--- a/piker/ui/order_mode.py
+++ b/piker/ui/order_mode.py
@@ -27,7 +27,6 @@ import time
 from typing import Optional, Dict, Callable, Any
 import uuid
 
-from pydantic import BaseModel
 import tractor
 import trio
 from PyQt5.QtCore import Qt
@@ -41,6 +40,7 @@ from ..clearing._allocate import (
 from ._style import _font
 from ..data._source import Symbol
 from ..data.feed import Feed
+from ..data.types import Struct
 from ..log import get_logger
 from ._editors import LineEditor, ArrowEditor
 from ._lines import order_line, LevelLine
@@ -58,7 +58,7 @@ from ._forms import open_form_input_handling
 log = get_logger(__name__)
 
 
-class OrderDialog(BaseModel):
+class OrderDialog(Struct):
     '''
     Trade dialogue meta-data describing the lifetime
     of an order submission to ``emsd`` from a chart.
@@ -73,10 +73,6 @@ class OrderDialog(BaseModel):
     msgs: dict[str, dict] = {}
     fills: Dict[str, Any] = {}
 
-    class Config:
-        arbitrary_types_allowed = True
-        underscore_attrs_are_private = False
-
 
 def on_level_change_update_next_order_info(
 
@@ -268,7 +264,8 @@ class OrderMode:
         self,
 
     ) -> OrderDialog:
-        '''Send execution order to EMS return a level line to
+        '''
+        Send execution order to EMS return a level line to
         represent the order on a chart.
 
         '''
@@ -277,13 +274,9 @@ class OrderMode:
         oid = str(uuid.uuid4())
 
         # format order data for ems
-        fqsn = symbol.front_fqsn()
-        order = staged.copy(
-            update={
-                'symbol': fqsn,
-                'oid': oid,
-            }
-        )
+        order = staged.copy()
+        order.oid = oid
+        order.symbol = symbol.front_fqsn()
 
         line = self.line_from_order(
             order,
@@ -858,7 +851,9 @@ async def process_trades_and_update_ui(
             # delete level line from view
             mode.on_cancel(oid)
             broker_msg = msg['brokerd_msg']
-            log.warning(f'Order {oid} failed with:\n{pformat(broker_msg)}')
+            log.warning(
+                f'Order {oid} failed with:\n{pformat(broker_msg)}'
+            )
 
         elif resp in (
             'dark_triggered'
diff --git a/setup.py b/setup.py
index 9ae98dbb..71cc078b 100755
--- a/setup.py
+++ b/setup.py
@@ -47,12 +47,11 @@ setup(
         'attrs',
         'pygments',
         'colorama',  # numba traceback coloring
-        'pydantic',  # structured data
+        'msgspec',  # performant IPC messaging and structs
 
         # async
         'trio',
         'trio-websocket',
-        'msgspec',  # performant IPC messaging
         'async_generator',
 
         # from github currently (see requirements.txt)