[codex] Guard dedup scopes by written columns (#23)

* Guard dedup scopes by written columns

* Address dedup scope review feedback

* Remove legacy dedup scope support

* Remove stale legacy descriptions

* chore: bump version from 0.5.1 to 0.5.2

README.md

@@ -133,8 +133,11 @@ update_history_with_config(
 - **`update_history`**: incremental append based on existing SQLite `MAX(time)` per symbol (and timeframe for rates); account-level deals use a separate cursor when `include_account_events=True`.
 - **`rates` table**: normalized storage with `symbol` and `timeframe` columns.
 - **Rate compatibility views**: mt5cli manages all `rate_*` views. Naming is `rate_<symbol>__<timeframe>` when a symbol has one timeframe, otherwise `rate_<symbol>__<granularity>_<timeframe>` (for example `rate_EURUSD__M1_1`). Stale `rate_*` views are dropped and recreated when rates change for offline tools such as mteor optimize.
-- **Rate view resolution**: use `mt5cli.history.resolve_rate_view_name()` / `resolve_rate_view_names()` to map symbols and granularities to existing SQLite compatibility views without creating databases.
+- **Rate view resolution**: use `resolve_rate_view_name()` / `resolve_rate_view_names()` to map symbols and granularities to existing SQLite compatibility views without creating databases. Both accept `None` (or a missing path) and return deterministic default names unless `require_existing=True`.
 - **Rate view loading**: use `load_rate_data()` / `load_rate_data_from_connection()` to load a SQLite rate table or view into a `DatetimeIndex` DataFrame.
+- **Multi-series rate loading**: use `build_rate_targets()` to build neutral `RateTarget(symbol, timeframe)` pairs, `resolve_rate_tables()` to map them to table/view names (pass `require_existing=True` for strict resolution), and `load_rate_series_from_sqlite()` to load them into a mapping keyed by `(symbol, integer timeframe)`. The loader requires existing managed views unless `explicit_tables` is supplied, and rejects duplicate `(symbol, timeframe)` targets.
+- **Multi-account latest rates**: use `collect_latest_rates_for_accounts()` with `AccountSpec` to read the latest bars for several account groups, merged into a `(symbol, integer timeframe)` mapping.
+- **MT5 session helper**: use the `mt5_session()` context manager to attach to (or, when `Mt5Config.path` is set, launch) an MT5 terminal, log in, and yield a connected `Mt5CliClient` that shuts down on exit.
 - **SQLite export helpers**: use `export_dataframe_to_sqlite()` for append mode, optional index export, and post-write deduplication by key columns.
 - **Recent ticks and margins**: `recent_ticks()` and `minimum_margins()` SDK helpers (and matching CLI commands) cover common downstream read-only queries.
 

docs/api/history.md

@@ -133,8 +133,8 @@ The `update_history` SDK path uses the same base tables and optional
 ### Rate view resolution
 
 Downstream tools can resolve mt5cli-managed compatibility view names from an
-existing SQLite history database without creating files or guessing legacy
+existing SQLite history database without creating files or guessing naming
-naming schemes:
+schemes:
 
 ```python
 from pathlib import Path
@@ -183,3 +183,35 @@ rates = load_rate_data(Path("history.db"), view, count=1000)
 The loader accepts close-based OHLC rate data or tick-like bid/ask data. It
 validates that `time` exists, parses timestamps with pandas, and returns a
 DataFrame indexed by ascending `DatetimeIndex` named `time`.
+
+### Multi-series rate loading
+
+For loading many rate series at once, build neutral `RateTarget` pairs and load
+them from SQLite in one call. View names are resolved via the same
+compatibility-view rules, or you can pass `explicit_tables` to bypass resolution:
+
+```python
+from pathlib import Path
+
+from mt5cli import build_rate_targets, load_rate_series_from_sqlite
+
+targets = build_rate_targets(["EURUSD", "GBPUSD"], ["M1", "H1"])
+series = load_rate_series_from_sqlite(Path("history.db"), targets, count=1000)
+frame = series["EURUSD", 1]  # keyed by (symbol, integer timeframe)
+```
+
+- `build_rate_targets()` returns `RateTarget(symbol, timeframe)` pairs in
+  row-major order, normalizing timeframe names such as `"M1"` to their integer
+  values; set `allow_missing_symbol=True` to address series solely by
+  `explicit_tables` (targets carry `symbol=None`).
+- `resolve_rate_tables()` maps targets to table or view names and validates that
+  any `explicit_tables` count matches the target count. Pass
+  `require_existing=True` to raise `ValueError` instead of returning a
+  best-guess name when the database or managed view is missing. When
+  `explicit_tables` is provided, names are returned as-is and
+  `require_existing` is ignored.
+- `load_rate_series_from_sqlite()` returns a mapping keyed by
+  `(symbol, integer timeframe)`. Unless `explicit_tables` is supplied, it
+  requires existing managed `rate_*` compatibility views and raises
+  `ValueError` when they are missing. Duplicate `(symbol, timeframe)` targets
+  are rejected.

mt5cli/__init__.py

@@ -2,13 +2,28 @@
 
 from importlib.metadata import version
 
-from .history import load_rate_data, load_rate_data_from_connection
+from .history import (
+    RateTarget,
+    build_rate_targets,
+    build_rate_view_name,
+    load_rate_data,
+    load_rate_data_from_connection,
+    load_rate_series_from_sqlite,
+    resolve_history_datasets,
+    resolve_history_tick_flags,
+    resolve_history_timeframes,
+    resolve_rate_tables,
+    resolve_rate_view_name,
+    resolve_rate_view_names,
+)
 from .sdk import (
+    AccountSpec,
     Mt5CliClient,
     account_info,
     build_config,
     collect_history,
     collect_latest_rates,
+    collect_latest_rates_for_accounts,
     copy_rates_from,
     copy_rates_from_pos,
     copy_rates_range,
@@ -20,6 +35,7 @@ from .sdk import (
     latest_rates,
     market_book,
     minimum_margins,
+    mt5_session,
     mt5_summary,
     mt5_summary_as_df,
     orders,
@@ -37,23 +53,35 @@ from .sdk import (
     version as mt5_version,
 )
 from .utils import (
+    TICK_FLAG_MAP,
+    TIMEFRAME_MAP,
     Dataset,
     IfExists,
     detect_format,
     export_dataframe,
     export_dataframe_to_sqlite,
+    parse_datetime,
+    parse_tick_flags,
+    parse_timeframe,
 )
 
 __version__ = version(__package__) if __package__ else None
 
 __all__ = [
+    "TICK_FLAG_MAP",
+    "TIMEFRAME_MAP",
+    "AccountSpec",
     "Dataset",
     "IfExists",
     "Mt5CliClient",
+    "RateTarget",
     "account_info",
     "build_config",
+    "build_rate_targets",
+    "build_rate_view_name",
     "collect_history",
     "collect_latest_rates",
+    "collect_latest_rates_for_accounts",
     "copy_rates_from",
     "copy_rates_from_pos",
     "copy_rates_range",
@@ -68,15 +96,26 @@ __all__ = [
     "latest_rates",
     "load_rate_data",
     "load_rate_data_from_connection",
+    "load_rate_series_from_sqlite",
     "market_book",
     "minimum_margins",
+    "mt5_session",
     "mt5_summary",
     "mt5_summary_as_df",
     "mt5_version",
     "orders",
+    "parse_datetime",
+    "parse_tick_flags",
+    "parse_timeframe",
     "positions",
     "recent_history_deals",
     "recent_ticks",
+    "resolve_history_datasets",
+    "resolve_history_tick_flags",
+    "resolve_history_timeframes",
+    "resolve_rate_tables",
+    "resolve_rate_view_name",
+    "resolve_rate_view_names",
     "symbol_info",
     "symbol_info_tick",
     "symbols",

mt5cli/history.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import logging
 import sqlite3
+from dataclasses import dataclass
 from datetime import UTC, datetime
 from pathlib import Path
 from typing import TYPE_CHECKING, Literal, cast
@@ -20,7 +21,7 @@ from .utils import (
 )
 
 if TYPE_CHECKING:
-    from collections.abc import Callable, Sequence
+    from collections.abc import Callable, Mapping, Sequence
 
     from pdmt5 import Mt5DataClient
 
@@ -135,14 +136,17 @@ def _require_non_empty_identifier(identifier: str, kind: str) -> str:
 
 
 def _open_history_connection(
-    conn_or_path: SqliteConnOrPath,
+    conn_or_path: SqliteConnOrPath | None,
 ) -> tuple[sqlite3.Connection | None, bool]:
     """Open a read-only SQLite connection when given a path.
 
     Returns:
-        A connection and whether the caller should close it. When the path does
+        A connection and whether the caller should close it. When ``conn_or_path``
-        not exist, returns ``(None, False)`` without creating a database file.
+        is None or the path does not exist, returns ``(None, False)`` without
+        creating a database file.
     """
+    if conn_or_path is None:
+        return None, False
     if isinstance(conn_or_path, sqlite3.Connection):
         return conn_or_path, False
     path = Path(conn_or_path)
@@ -376,7 +380,7 @@ def _resolve_rate_view_name_from_context(
 
 
 def resolve_rate_view_name(
-    conn_or_path: SqliteConnOrPath,
+    conn_or_path: SqliteConnOrPath | None,
     symbol: str,
     granularity: str,
     *,
@@ -385,7 +389,9 @@ def resolve_rate_view_name(
     """Resolve the mt5cli-managed rate compatibility view name.
 
     Args:
-        conn_or_path: SQLite database path or open connection.
+        conn_or_path: SQLite database path or open connection. When None or a
+            non-existing path and ``require_existing`` is False, the deterministic
+            default view name is returned without creating a database file.
         symbol: Symbol stored in the normalized ``rates`` table.
         granularity: Timeframe name (for example ``M1``) or integer string.
         require_existing: When True, require the database and a managed view to exist.
@@ -429,7 +435,7 @@ def resolve_rate_view_name(
 
 
 def resolve_rate_view_names(
-    conn_or_path: SqliteConnOrPath,
+    conn_or_path: SqliteConnOrPath | None,
     symbols: Sequence[str],
     granularities: Sequence[str],
     *,
@@ -438,7 +444,9 @@ def resolve_rate_view_names(
     """Resolve rate compatibility view names for symbol and granularity pairs.
 
     Args:
-        conn_or_path: SQLite database path or open connection.
+        conn_or_path: SQLite database path or open connection. When None or a
+            non-existing path and ``require_existing`` is False, deterministic
+            default view names are returned without creating a database file.
         symbols: Symbols stored in the normalized ``rates`` table.
         granularities: Timeframe names (for example ``M1``) or integer strings.
         require_existing: When True, require the database and managed views to exist.
@@ -482,6 +490,222 @@ def resolve_rate_view_names(
             conn.close()
 
 
+@dataclass(frozen=True)
+class RateTarget:
+    """A single rate series identified by symbol and timeframe.
+
+    Attributes:
+        symbol: MT5 symbol name, or None when the rate series is addressed only
+            by an explicit table (for example a custom SQLite view).
+        timeframe: MT5 timeframe as an integer or name (for example ``M1``).
+    """
+
+    symbol: str | None
+    timeframe: int | str
+
+    def __post_init__(self) -> None:
+        """Normalize accepted timeframe aliases to the stored integer value."""
+        if not isinstance(self.timeframe, int):
+            object.__setattr__(self, "timeframe", parse_timeframe(self.timeframe))
+
+    @property
+    def timeframe_int(self) -> int:
+        """Return the timeframe as its integer MT5 value."""
+        return cast("int", self.timeframe)
+
+
+def build_rate_targets(
+    symbols: Sequence[str],
+    timeframes: Sequence[int | str],
+    *,
+    allow_missing_symbol: bool = False,
+) -> list[RateTarget]:
+    """Build rate targets for every symbol and timeframe combination.
+
+    Args:
+        symbols: MT5 symbol names. May be empty when ``allow_missing_symbol``.
+        timeframes: MT5 timeframes as integers or names (for example ``M1``).
+        allow_missing_symbol: When True and ``symbols`` is empty, build targets
+            with ``symbol=None`` for each timeframe instead of raising.
+
+    Returns:
+        Targets in row-major order: every timeframe for the first symbol, then
+        every timeframe for the next symbol, and so on.
+
+    Raises:
+        ValueError: If ``timeframes`` is empty, or ``symbols`` is empty and
+            ``allow_missing_symbol`` is False.
+    """
+    if not timeframes:
+        msg = "At least one timeframe is required."
+        raise ValueError(msg)
+    if not symbols:
+        if not allow_missing_symbol:
+            msg = "At least one symbol is required."
+            raise ValueError(msg)
+        return [RateTarget(symbol=None, timeframe=tf) for tf in timeframes]
+    return [
+        RateTarget(symbol=symbol, timeframe=tf)
+        for symbol in symbols
+        for tf in timeframes
+    ]
+
+
+def resolve_rate_tables(
+    conn_or_path: SqliteConnOrPath | None,
+    targets: Sequence[RateTarget],
+    explicit_tables: Sequence[str] | None = None,
+    *,
+    require_existing: bool = False,
+) -> list[str]:
+    """Resolve SQLite table or view names for rate targets.
+
+    Args:
+        conn_or_path: SQLite database path or open connection. May be None when
+            ``explicit_tables`` is provided, or when ``require_existing`` is
+            False and deterministic default view names are sufficient.
+        targets: Rate targets to resolve.
+        explicit_tables: Optional explicit table or view names. When provided,
+            they are used as-is and must match the number of targets.
+        require_existing: When True, require the database and managed views to
+            exist for each symbol target. Ignored when ``explicit_tables`` is
+            provided.
+
+    Returns:
+        Table or view names aligned with ``targets``.
+
+    Raises:
+        ValueError: If ``targets`` is empty, ``explicit_tables`` length does not
+            match the target count, a target without a symbol is resolved
+            without an explicit table, or ``require_existing`` is True and the
+            database or a managed view is missing.
+    """
+    target_list = list(targets)
+    if not target_list:
+        msg = "At least one rate target is required."
+        raise ValueError(msg)
+    if explicit_tables is not None:
+        tables = list(explicit_tables)
+        if len(tables) != len(target_list):
+            msg = (
+                f"Expected {len(target_list)} explicit table(s) "
+                f"to match the targets, got {len(tables)}."
+            )
+            raise ValueError(msg)
+        return tables
+    if any(target.symbol is None for target in target_list):
+        msg = (
+            "Cannot resolve a rate table for a target without a symbol; "
+            "provide explicit_tables."
+        )
+        raise ValueError(msg)
+    conn, should_close = _open_history_connection(conn_or_path)
+    try:
+        if conn is None:
+            if require_existing:
+                path = (
+                    conn_or_path
+                    if isinstance(conn_or_path, (Path, str))
+                    else "database"
+                )
+                msg = f"SQLite database not found: {path}"
+                raise ValueError(msg)
+            timeframe_counts = None
+            existing_views: set[str] = set()
+        else:
+            timeframe_counts = _load_rates_timeframe_counts(conn)
+            existing_views = _load_existing_rate_views(conn)
+        resolved: list[str] = []
+        for target in target_list:
+            symbol = cast("str", target.symbol)
+            timeframe = target.timeframe_int
+            resolved.append(
+                _resolve_rate_view_name_from_context(
+                    symbol=symbol,
+                    timeframe=timeframe,
+                    granularity_name=resolve_granularity_name(timeframe),
+                    timeframe_counts=timeframe_counts,
+                    existing_views=existing_views,
+                    require_existing=require_existing,
+                ),
+            )
+        return resolved
+    finally:
+        if should_close and conn is not None:
+            conn.close()
+
+
+def load_rate_series_from_sqlite(
+    conn_or_path: SqliteConnOrPath,
+    targets: Sequence[RateTarget],
+    count: int,
+    explicit_tables: Sequence[str] | None = None,
+) -> dict[tuple[str | None, int], pd.DataFrame]:
+    """Load multiple rate series from a SQLite database.
+
+    Args:
+        conn_or_path: SQLite database path or open connection.
+        targets: Rate targets to load. Each ``(symbol, timeframe_int)`` pair
+            must be unique.
+        count: Number of most recent rows to load per series.
+        explicit_tables: Optional explicit table or view names matching targets.
+            When omitted, managed ``rate_*`` compatibility views must already
+            exist in the database.
+
+    Returns:
+        Mapping keyed by ``(symbol, timeframe_int)`` to each rate DataFrame.
+
+    Raises:
+        ValueError: If ``count`` is not positive, targets are empty, duplicate
+            ``(symbol, timeframe_int)`` pairs are present, or table resolution
+            fails.
+    """
+    if count <= 0:
+        msg = "count must be positive."
+        raise ValueError(msg)
+    target_list = list(targets)
+    if not target_list:
+        msg = "At least one rate target is required."
+        raise ValueError(msg)
+    if explicit_tables is None and any(target.symbol is None for target in target_list):
+        msg = (
+            "Cannot resolve a rate table for a target without a symbol; "
+            "provide explicit_tables."
+        )
+        raise ValueError(msg)
+    seen_keys: set[tuple[str | None, int]] = set()
+    for target in target_list:
+        key = (target.symbol, target.timeframe_int)
+        if key in seen_keys:
+            symbol_repr = repr(target.symbol)
+            msg = f"Duplicate rate target: ({symbol_repr}, {target.timeframe_int})"
+            raise ValueError(msg)
+        seen_keys.add(key)
+    tables = (
+        resolve_rate_tables(None, target_list, explicit_tables)
+        if explicit_tables is not None
+        else None
+    )
+    conn, should_close = _open_existing_sqlite_database(conn_or_path)
+    try:
+        resolved_tables = tables or resolve_rate_tables(
+            conn,
+            target_list,
+            require_existing=True,
+        )
+        return {
+            (target.symbol, target.timeframe_int): load_rate_data_from_connection(
+                conn,
+                table,
+                count=count,
+            )
+            for target, table in zip(target_list, resolved_tables, strict=True)
+        }
+    finally:
+        if should_close:
+            conn.close()
+
+
 def get_table_columns(conn: sqlite3.Connection, table: str) -> set[str]:
     """Return existing SQLite columns for a table."""
     quoted_table = quote_sqlite_identifier(table)
@@ -765,7 +989,20 @@ def drop_duplicates_in_table(
     )
 
 
-DedupScope = tuple[str, tuple[object, ...]]
+@dataclass(frozen=True)
+class DedupScope:
+    """Scoped deduplication predicate and the columns it references.
+
+    Attributes:
+        where: SQL predicate appended to the duplicate-removal query.
+        params: Parameters bound to the scope predicate.
+        required_columns: Columns that must be present in the written table for
+            the scope to run.
+    """
+
+    where: str
+    params: tuple[object, ...]
+    required_columns: frozenset[str]
 
 
 def _record_dedup_scope(
@@ -773,17 +1010,25 @@ def _record_dedup_scope(
     dataset: Dataset,
     scope_where: str,
     scope_params: tuple[object, ...],
+    required_columns: frozenset[str],
 ) -> None:
-    dedup_scopes.setdefault(dataset, []).append((scope_where, scope_params))
+    dedup_scopes.setdefault(dataset, []).append(
+        DedupScope(scope_where, scope_params, required_columns),
+    )
 
 
 def deduplicate_history_tables(
     conn: sqlite3.Connection,
     written_columns: dict[Dataset, set[str]],
     written_tables: set[Dataset],
-    dedup_scopes: dict[Dataset, list[DedupScope]] | None = None,
+    dedup_scopes: Mapping[Dataset, Sequence[DedupScope]] | None = None,
 ) -> None:
-    """Deduplicate appended history tables by stable identifiers."""
+    """Deduplicate appended history tables by stable identifiers.
+
+    Scopes whose required columns are not present in the written table are
+    skipped. If all scopes for a dataset are skipped, the table receives one
+    unscoped deduplication pass instead.
+    """
     cursor = conn.cursor()
     for dataset in written_tables:
         columns = written_columns.get(dataset, set())
@@ -802,16 +1047,19 @@ def deduplicate_history_tables(
                 table,
             )
             continue
-        scopes = dedup_scopes.get(dataset, []) if dedup_scopes else []
+        raw_scopes: Sequence[DedupScope] = (
+            dedup_scopes.get(dataset, ()) if dedup_scopes else ()
+        )
+        scopes = [scope for scope in raw_scopes if scope.required_columns <= columns]
         if scopes:
-            for scope_where, scope_params in scopes:
+            for scope in scopes:
                 drop_duplicates_in_table(
                     cursor,
                     table,
                     list(keys),
                     keep="last",
-                    scope_where=scope_where,
+                    scope_where=scope.where,
-                    scope_params=scope_params,
+                    scope_params=scope.params,
                 )
             continue
         drop_duplicates_in_table(cursor, table, list(keys), keep="last")
@@ -1178,6 +1426,7 @@ def _write_incremental_rates(
                     Dataset.rates,
                     "symbol = ? AND timeframe = ? AND time >= ?",
                     (symbol, timeframe, start_date),
+                    frozenset({"symbol", "timeframe", "time"}),
                 )
 
 
@@ -1216,6 +1465,7 @@ def _write_incremental_ticks(
                 Dataset.ticks,
                 "symbol = ? AND time >= ?",
                 (symbol, start_date),
+                frozenset({"symbol", "time"}),
             )
 
 
@@ -1254,6 +1504,7 @@ def _write_incremental_history_orders(
                 Dataset.history_orders,
                 "symbol = ? AND time >= ?",
                 (symbol, start_date),
+                frozenset({"symbol", "time"}),
             )
 
 
@@ -1307,6 +1558,7 @@ def _write_incremental_history_deals(
                         Dataset.history_deals,
                         "symbol = ? AND time >= ?",
                         (symbol, start_by_symbol[symbol, None]),
+                        frozenset({"symbol", "time"}),
                     )
             if "type" in columns:
                 _record_dedup_scope(
@@ -1314,6 +1566,7 @@ def _write_incremental_history_deals(
                     Dataset.history_deals,
                     f"type NOT IN {_TRADE_DEAL_TYPES_SQL} AND time >= ?",
                     (account_event_start,),
+                    frozenset({"type", "time"}),
                 )
             if "type" not in columns and "symbol" in columns:
                 _record_dedup_scope(
@@ -1321,6 +1574,7 @@ def _write_incremental_history_deals(
                     Dataset.history_deals,
                     "(symbol IS NULL OR symbol = '') AND time >= ?",
                     (account_event_start,),
+                    frozenset({"symbol", "time"}),
                 )
         return
     start_by_symbol = load_incremental_start_datetimes(
@@ -1348,6 +1602,7 @@ def _write_incremental_history_deals(
                 Dataset.history_deals,
                 "symbol = ? AND time >= ?",
                 (symbol, start_date),
+                frozenset({"symbol", "time"}),
             )
 
 

mt5cli/sdk.py

@@ -6,7 +6,7 @@ import json
 import logging
 import sqlite3
 from contextlib import contextmanager
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from datetime import UTC, datetime, timedelta
 from pathlib import Path
 from typing import TYPE_CHECKING, Self, TypeVar, cast
@@ -40,11 +40,13 @@ T = TypeVar("T")
 logger = logging.getLogger(__name__)
 
 __all__ = [
+    "AccountSpec",
     "Mt5CliClient",
     "account_info",
     "build_config",
     "collect_history",
     "collect_latest_rates",
+    "collect_latest_rates_for_accounts",
     "copy_rates_from",
     "copy_rates_from_pos",
     "copy_rates_range",
@@ -56,6 +58,7 @@ __all__ = [
     "latest_rates",
     "market_book",
     "minimum_margins",
+    "mt5_session",
     "mt5_summary",
     "mt5_summary_as_df",
     "orders",
@@ -277,6 +280,26 @@ def _run_with_client(
         return fetch_fn(client)
 
 
+@contextmanager
+def mt5_session(config: Mt5Config | None = None) -> Iterator[Mt5CliClient]:
+    """Open an MT5 terminal session and yield a connected client.
+
+    Launches the MetaTrader 5 terminal using ``Mt5Config.path`` (when set),
+    logs in, yields a connected :class:`Mt5CliClient`, and always shuts the
+    terminal down on exit.
+
+    Args:
+        config: MT5 connection configuration. Defaults to an empty config that
+            attaches to a running terminal.
+
+    Yields:
+        Connected ``Mt5CliClient`` bound to the session.
+    """
+    mt5_config = config or build_config()
+    with _connected_client(mt5_config) as client:
+        yield Mt5CliClient.from_connected_client(client)
+
+
 class Mt5CliClient:
     """Programmatic client for read-only MetaTrader 5 data access."""
 
@@ -1075,6 +1098,120 @@ def collect_latest_rates(
     )
 
 
+@dataclass(frozen=True)
+class AccountSpec:
+    """Connection parameters and symbols for one MT5 account group.
+
+    Attributes:
+        symbols: Symbols to load latest rates for under this account.
+        login: Trading account login. String values are coerced to int when
+            non-empty.
+        password: Trading account password.
+        server: Trading server name.
+        path: Path to the MetaTrader5 terminal EXE file.
+        timeout: Connection timeout in milliseconds.
+    """
+
+    symbols: Sequence[str]
+    login: int | str | None = None
+    password: str | None = field(default=None, repr=False)
+    server: str | None = None
+    path: str | None = None
+    timeout: int | None = None
+
+
+def _coerce_login(login: int | str | None) -> int | None:
+    """Coerce a login value to int, treating empty strings as unset.
+
+    Returns:
+        Integer login, or None when unset or an empty string.
+    """
+    if login is None or isinstance(login, int):
+        return login
+    text = login.strip()
+    if not text:
+        return None
+    return int(text)
+
+
+def _build_account_config(
+    account: AccountSpec,
+    base_config: Mt5Config | None,
+) -> Mt5Config:
+    """Build an ``Mt5Config`` for an account, falling back to ``base_config``.
+
+    Returns:
+        Merged MT5 configuration for the account.
+    """
+    login = _coerce_login(account.login)
+    if login is None and base_config is not None:
+        login = base_config.login
+    return build_config(
+        path=account.path or (base_config.path if base_config else None),
+        login=login,
+        password=account.password or (base_config.password if base_config else None),
+        server=account.server or (base_config.server if base_config else None),
+        timeout=account.timeout
+        if account.timeout is not None
+        else (base_config.timeout if base_config else None),
+    )
+
+
+def collect_latest_rates_for_accounts(
+    accounts: Sequence[AccountSpec],
+    timeframes: Sequence[int | str],
+    count: int,
+    *,
+    start_pos: int = 0,
+    base_config: Mt5Config | None = None,
+) -> dict[tuple[str, int], pd.DataFrame]:
+    """Collect latest rates across multiple MT5 account groups.
+
+    Each account is connected in turn, its symbols are read for every
+    timeframe, and the resulting frames are merged into a single mapping.
+
+    Args:
+        accounts: Account groups to read. Each must define at least one symbol.
+        timeframes: MT5 timeframes as integers or names (for example ``M1``).
+        count: Number of most recent bars to read per symbol/timeframe.
+        start_pos: Initial bar position offset.
+        base_config: Optional base configuration whose fields fill any value not
+            set on an individual account.
+
+    Returns:
+        Mapping keyed by ``(symbol, timeframe_int)``. When accounts share a
+        symbol/timeframe pair, the last account processed wins.
+
+    Raises:
+        ValueError: If ``accounts``, ``timeframes``, or any account's symbols are
+            empty, or ``count`` is not positive.
+    """
+    account_list = list(accounts)
+    if not account_list:
+        msg = "At least one account is required."
+        raise ValueError(msg)
+    if not timeframes:
+        msg = "At least one timeframe is required."
+        raise ValueError(msg)
+    if any(not account.symbols for account in account_list):
+        msg = "Each account requires at least one symbol."
+        raise ValueError(msg)
+    _require_positive(count, "count")
+    result: dict[tuple[str, int], pd.DataFrame] = {}
+    for account in account_list:
+        config = _build_account_config(account, base_config)
+        with Mt5CliClient(config=config) as client:
+            result.update(
+                client.collect_latest_rates(
+                    account.symbols,
+                    timeframes,
+                    count=count,
+                    start_pos=start_pos,
+                ),
+            )
+    return result
+
+
 def copy_rates_range(
     symbol: str,
     timeframe: int | str,

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "mt5cli"
-version = "0.5.0"
+version = "0.5.2"
 description = "Command-line tool for MetaTrader 5"
 authors = [{name = "dceoy", email = "dceoy@users.noreply.github.com"}]
 maintainers = [{name = "dceoy", email = "dceoy@users.noreply.github.com"}]

tests/test_history.py

@@ -10,14 +10,19 @@ from unittest.mock import MagicMock
 
 import pandas as pd
 import pytest
+from pytest_mock import MockerFixture  # noqa: TC002
 
 if TYPE_CHECKING:
     from pathlib import Path
 
+from mt5cli import history
 from mt5cli.history import (
     DEFAULT_HISTORY_TIMEFRAMES,
+    DedupScope,
+    RateTarget,
     append_dataframe,
     augment_written_columns_from_sqlite,
+    build_rate_targets,
     build_rate_view_name,
     create_cash_events_view,
     create_history_indexes,
@@ -33,6 +38,7 @@ from mt5cli.history import (
     load_incremental_start_datetimes,
     load_rate_data,
     load_rate_data_from_connection,
+    load_rate_series_from_sqlite,
     parse_sqlite_timestamp,
     quote_sqlite_identifier,
     record_written_columns,
@@ -40,6 +46,7 @@ from mt5cli.history import (
     resolve_history_datasets,
     resolve_history_tick_flags,
     resolve_history_timeframes,
+    resolve_rate_tables,
     resolve_rate_view_name,
     resolve_rate_view_names,
     write_collected_datasets,
@@ -60,6 +67,21 @@ class TestResolveRateViewName:
         assert resolve_rate_view_name(db_path, "EURUSD", "M1") == "rate_EURUSD__1"
         assert not db_path.exists()
 
+    def test_none_path_returns_default_name(self) -> None:
+        """Test a None connection or path returns the deterministic default."""
+        assert resolve_rate_view_name(None, "EURUSD", "M1") == "rate_EURUSD__1"
+        assert resolve_rate_view_names(None, ["EURUSD"], ["M1", "H1"]) == [
+            "rate_EURUSD__1",
+            "rate_EURUSD__16385",
+        ]
+
+    def test_none_path_with_require_existing_raises(self) -> None:
+        """Test a None path under strict mode raises a clear error."""
+        with pytest.raises(ValueError, match="SQLite database not found"):
+            resolve_rate_view_name(None, "EURUSD", "M1", require_existing=True)
+        with pytest.raises(ValueError, match="SQLite database not found"):
+            resolve_rate_view_names(None, ["EURUSD"], ["M1"], require_existing=True)
+
     def test_no_rates_table_falls_back_to_single_timeframe_name(
         self,
         tmp_path: Path,
@@ -597,7 +619,7 @@ class TestIncrementalStart:
     ) -> None:
         """Test rates tables without timeframe fail fast during incremental resume."""
         fallback = datetime(2024, 1, 1, tzinfo=UTC)
-        with sqlite3.connect(tmp_path / "legacy-rates.db") as conn:
+        with sqlite3.connect(tmp_path / "rates-without-timeframe.db") as conn:
             conn.execute("CREATE TABLE rates(symbol TEXT, time TEXT, open REAL)")
             conn.execute(
                 "INSERT INTO rates(symbol, time, open) VALUES (?, ?, ?)",
@@ -866,9 +888,10 @@ class TestDeduplication:
                 {Dataset.rates},
                 {
                     Dataset.rates: [
-                        (
+                        DedupScope(
                             "symbol = ? AND timeframe = ? AND time >= ?",
                             ("EURUSD", 1, boundary),
+                            frozenset({"symbol", "timeframe", "time"}),
                         ),
                     ],
                 },
@@ -881,6 +904,89 @@ class TestDeduplication:
             ("2024-01-02T00:00:00+00:00", 9.9),
         ]
 
+    def test_unusable_scope_falls_back_to_table_dedup(self, tmp_path: Path) -> None:
+        """Test scopes with missing columns do not break stable-key dedup."""
+        boundary = datetime(2024, 1, 1, tzinfo=UTC)
+        with sqlite3.connect(tmp_path / "orders-without-time.db") as conn:
+            conn.execute(
+                "CREATE TABLE history_orders("
+                " ticket INTEGER, symbol TEXT, time_setup TEXT, type INTEGER)",
+            )
+            conn.executemany(
+                "INSERT INTO history_orders(ticket, symbol, time_setup, type)"
+                " VALUES (?, ?, ?, ?)",
+                [
+                    (1, "EURUSD", "2024-01-01T00:00:00+00:00", 0),
+                    (1, "EURUSD", "2024-01-01T00:00:01+00:00", 1),
+                ],
+            )
+            deduplicate_history_tables(
+                conn,
+                {Dataset.history_orders: {"ticket", "symbol", "time_setup", "type"}},
+                {Dataset.history_orders},
+                {
+                    Dataset.history_orders: [
+                        DedupScope(
+                            "symbol = ? AND time >= ?",
+                            ("EURUSD", boundary),
+                            frozenset({"symbol", "time"}),
+                        ),
+                    ],
+                },
+            )
+            rows = conn.execute(
+                "SELECT ticket, time_setup, type FROM history_orders",
+            ).fetchall()
+        assert rows == [(1, "2024-01-01T00:00:01+00:00", 1)]
+
+    def test_partially_unusable_scopes_only_run_usable_scopes(
+        self,
+        tmp_path: Path,
+    ) -> None:
+        """Test mixed scope filtering skips only scopes with missing columns."""
+        boundary = datetime(2024, 1, 2, tzinfo=UTC)
+        with sqlite3.connect(tmp_path / "partial-scope-filter.db") as conn:
+            conn.execute(
+                "CREATE TABLE rates("
+                " symbol TEXT, timeframe INTEGER, time TEXT, open REAL)",
+            )
+            conn.executemany(
+                "INSERT INTO rates(symbol, timeframe, time, open) VALUES (?, ?, ?, ?)",
+                [
+                    ("EURUSD", 1, "2024-01-02T00:00:00+00:00", 2.0),
+                    ("EURUSD", 1, "2024-01-02T00:00:00+00:00", 9.9),
+                    ("USDJPY", 1, "2024-01-02T00:00:00+00:00", 100.0),
+                    ("USDJPY", 1, "2024-01-02T00:00:00+00:00", 101.0),
+                ],
+            )
+            deduplicate_history_tables(
+                conn,
+                {Dataset.rates: {"symbol", "timeframe", "time", "open"}},
+                {Dataset.rates},
+                {
+                    Dataset.rates: [
+                        DedupScope(
+                            "symbol = ? AND timeframe = ? AND time >= ?",
+                            ("EURUSD", 1, boundary),
+                            frozenset({"symbol", "timeframe", "time"}),
+                        ),
+                        DedupScope(
+                            "symbol = ? AND timeframe = ? AND broker = ?",
+                            ("USDJPY", 1, "demo"),
+                            frozenset({"symbol", "timeframe", "broker"}),
+                        ),
+                    ],
+                },
+            )
+            rows = conn.execute(
+                "SELECT symbol, open FROM rates ORDER BY symbol, open",
+            ).fetchall()
+        assert rows == [
+            ("EURUSD", 9.9),
+            ("USDJPY", 100.0),
+            ("USDJPY", 101.0),
+        ]
+
 
 class TestRateCompatibilityViews:
     """Tests for rate compatibility view creation."""
@@ -1341,6 +1447,54 @@ class TestIncrementalIntegration:
             "rate_EURUSD_M1__1",
         }
 
+    def test_incremental_orders_without_time_deduplicate_by_ticket(
+        self,
+        tmp_path: Path,
+        caplog: pytest.LogCaptureFixture,
+    ) -> None:
+        """Test incremental history_orders without time deduplicate safely."""
+
+        def history_orders_get_as_df(**kwargs: object) -> pd.DataFrame:
+            if kwargs["symbol"] == "GBPUSD":
+                return pd.DataFrame()
+            return pd.DataFrame({
+                "ticket": [1, 1],
+                "symbol": ["EURUSD", "EURUSD"],
+                "time_setup": [
+                    "2024-01-01T00:00:00+00:00",
+                    "2024-01-01T00:00:01+00:00",
+                ],
+                "type": [0, 1],
+            })
+
+        client = MagicMock()
+        client.history_orders_get_as_df.side_effect = history_orders_get_as_df
+        start = datetime(2024, 1, 1, tzinfo=UTC)
+        end = datetime(2024, 1, 2, tzinfo=UTC)
+        with (
+            sqlite3.connect(tmp_path / "incremental-orders-without-time.db") as conn,
+            caplog.at_level(logging.WARNING, logger="mt5cli.history"),
+        ):
+            write_incremental_datasets(
+                conn,
+                client,
+                ["EURUSD", "GBPUSD"],
+                {Dataset.history_orders},
+                [],
+                0,
+                start,
+                end,
+                deduplicate=True,
+                create_rate_views=False,
+                with_views=False,
+                include_account_events=False,
+            )
+            rows = conn.execute(
+                "SELECT ticket, time_setup, type FROM history_orders",
+            ).fetchall()
+        assert rows == [(1, "2024-01-01T00:00:01+00:00", 1)]
+        assert "Skipping history_orders: dataset returned no columns" in caplog.text
+
     def test_write_collected_datasets_and_edge_branches(
         self,
         tmp_path: Path,
@@ -1716,7 +1870,7 @@ class TestIncrementalHistoryDeals:
         })
         start = datetime(2024, 1, 1, tzinfo=UTC)
         end = datetime(2024, 1, 3, tzinfo=UTC)
-        with sqlite3.connect(tmp_path / "legacy-deals.db") as conn:
+        with sqlite3.connect(tmp_path / "deals-without-type.db") as conn:
             conn.execute(
                 "CREATE TABLE history_deals( ticket INTEGER, symbol TEXT, time TEXT)",
             )
@@ -1915,3 +2069,305 @@ class TestWriteHelpers:
             )
             assert get_table_columns(conn, "rates") == {"time", "open"}
             create_history_indexes(conn, written_columns)
+
+
+class TestRateSourceHelpers:
+    """Tests for generic rate-source SDK helpers."""
+
+    def test_rate_target_timeframe_int(self) -> None:
+        """Test RateTarget resolves named and integer timeframes."""
+        target = RateTarget(symbol="EURUSD", timeframe="M1")
+        assert target.timeframe == 1
+        assert target.timeframe_int == 1
+        assert RateTarget(symbol="EURUSD", timeframe=16385).timeframe_int == 16385
+
+    def test_build_rate_targets_row_major(self) -> None:
+        """Test targets are built in row-major symbol/timeframe order."""
+        targets = build_rate_targets(["EURUSD", "GBPUSD"], ["M1", "H1"])
+        assert [(t.symbol, t.timeframe) for t in targets] == [
+            ("EURUSD", 1),
+            ("EURUSD", 16385),
+            ("GBPUSD", 1),
+            ("GBPUSD", 16385),
+        ]
+
+    def test_build_rate_targets_allows_missing_symbol(self) -> None:
+        """Test missing symbols produce None-symbol targets when allowed."""
+        targets = build_rate_targets([], ["M1", "H1"], allow_missing_symbol=True)
+        assert [(t.symbol, t.timeframe) for t in targets] == [
+            (None, 1),
+            (None, 16385),
+        ]
+
+    @pytest.mark.parametrize(
+        ("symbols", "timeframes", "match"),
+        [
+            (["EURUSD"], [], "At least one timeframe"),
+            ([], ["M1"], "At least one symbol"),
+        ],
+    )
+    def test_build_rate_targets_rejects_empty(
+        self,
+        symbols: list[str],
+        timeframes: list[str],
+        match: str,
+    ) -> None:
+        """Test target building input validation."""
+        with pytest.raises(ValueError, match=match):
+            build_rate_targets(symbols, timeframes)
+
+    def test_resolve_rate_tables_uses_explicit_tables(self) -> None:
+        """Test explicit tables bypass view resolution when counts match."""
+        targets = build_rate_targets([], ["M1", "H1"], allow_missing_symbol=True)
+        assert resolve_rate_tables(None, targets, ["t1", "t2"]) == ["t1", "t2"]
+
+    def test_resolve_rate_tables_rejects_mismatched_explicit_count(self) -> None:
+        """Test explicit table count must match the number of targets."""
+        targets = build_rate_targets(["EURUSD"], ["M1"])
+        with pytest.raises(ValueError, match="Expected 1 explicit table"):
+            resolve_rate_tables(None, targets, ["t1", "t2"])
+
+    def test_resolve_rate_tables_rejects_empty_targets(self) -> None:
+        """Test resolving requires at least one target."""
+        with pytest.raises(ValueError, match="At least one rate target"):
+            resolve_rate_tables(None, [])
+
+    def test_resolve_rate_tables_requires_symbol_without_explicit(self) -> None:
+        """Test None-symbol targets require explicit tables."""
+        targets = build_rate_targets([], ["M1"], allow_missing_symbol=True)
+        with pytest.raises(ValueError, match="without a symbol"):
+            resolve_rate_tables(None, targets)
+
+    def test_resolve_rate_tables_resolves_view_names(self) -> None:
+        """Test symbol targets resolve to default view names without a database."""
+        targets = build_rate_targets(["EURUSD"], ["M1", "H1"])
+        assert resolve_rate_tables(None, targets) == [
+            "rate_EURUSD__1",
+            "rate_EURUSD__16385",
+        ]
+
+    def test_resolve_rate_tables_none_path_with_require_existing_raises(self) -> None:
+        """Test strict mode rejects a missing database path."""
+        targets = build_rate_targets(["EURUSD"], ["M1"])
+        with pytest.raises(ValueError, match="SQLite database not found"):
+            resolve_rate_tables(None, targets, require_existing=True)
+
+    def test_resolve_rate_tables_missing_db_with_require_existing_raises(
+        self,
+        tmp_path: Path,
+    ) -> None:
+        """Test strict mode rejects a non-existing database path."""
+        db_path = tmp_path / "missing.db"
+        targets = build_rate_targets(["EURUSD"], ["M1"])
+        with pytest.raises(ValueError, match="SQLite database not found"):
+            resolve_rate_tables(db_path, targets, require_existing=True)
+
+    def test_resolve_rate_tables_missing_view_with_require_existing_raises(
+        self,
+        tmp_path: Path,
+    ) -> None:
+        """Test strict mode rejects databases without managed rate views."""
+        db_path = tmp_path / "no-views.db"
+        with sqlite3.connect(db_path) as conn:
+            conn.execute(
+                "CREATE TABLE rates("
+                " symbol TEXT, timeframe INTEGER, time TEXT, close REAL)",
+            )
+            conn.execute(
+                "INSERT INTO rates(symbol, timeframe, time, close) VALUES (?, ?, ?, ?)",
+                ("EURUSD", 1, "2024-01-01T00:00:00+00:00", 1.0),
+            )
+        targets = build_rate_targets(["EURUSD"], ["M1"])
+        with pytest.raises(ValueError, match="No rate compatibility view exists"):
+            resolve_rate_tables(db_path, targets, require_existing=True)
+
+    def test_resolve_rate_tables_with_require_existing_resolves_views(
+        self,
+        tmp_path: Path,
+    ) -> None:
+        """Test strict mode resolves existing managed rate views."""
+        db_path = tmp_path / "strict-views.db"
+        with sqlite3.connect(db_path) as conn:
+            conn.execute(
+                "CREATE TABLE rates("
+                " symbol TEXT, timeframe INTEGER, time TEXT, close REAL)",
+            )
+            conn.execute(
+                "INSERT INTO rates(symbol, timeframe, time, close) VALUES (?, ?, ?, ?)",
+                ("EURUSD", 1, "2024-01-01T00:00:00+00:00", 1.0),
+            )
+            create_rate_compatibility_views(conn)
+        targets = build_rate_targets(["EURUSD"], ["M1"])
+        assert resolve_rate_tables(db_path, targets, require_existing=True) == [
+            "rate_EURUSD__1",
+        ]
+
+    def test_resolve_rate_tables_batches_sqlite_metadata(
+        self,
+        tmp_path: Path,
+        mocker: MockerFixture,
+    ) -> None:
+        """Test resolving multiple targets loads SQLite metadata once."""
+        db_path = tmp_path / "batch-rate-tables.db"
+        with sqlite3.connect(db_path) as conn:
+            conn.execute(
+                "CREATE TABLE rates("
+                " symbol TEXT, timeframe INTEGER, time TEXT, close REAL)",
+            )
+            conn.executemany(
+                "INSERT INTO rates(symbol, timeframe, time, close) VALUES (?, ?, ?, ?)",
+                [
+                    ("EURUSD", 1, "2024-01-01T00:00:00+00:00", 1.0),
+                    ("EURUSD", 16385, "2024-01-01T01:00:00+00:00", 1.1),
+                    ("GBPUSD", 1, "2024-01-01T00:00:00+00:00", 1.2),
+                ],
+            )
+            create_rate_compatibility_views(conn)
+        counts_spy = mocker.spy(history, "_load_rates_timeframe_counts")
+        views_spy = mocker.spy(history, "_load_existing_rate_views")
+
+        targets = build_rate_targets(["EURUSD", "GBPUSD"], ["M1", "H1"])
+        assert resolve_rate_tables(db_path, targets) == [
+            "rate_EURUSD__M1_1",
+            "rate_EURUSD__H1_16385",
+            "rate_GBPUSD__1",
+            "rate_GBPUSD__16385",
+        ]
+        assert counts_spy.call_count == 1
+        assert views_spy.call_count == 1
+
+    def test_load_rate_series_from_sqlite(self, tmp_path: Path) -> None:
+        """Test loading multiple rate series keyed by symbol and timeframe."""
+        db_path = tmp_path / "series.db"
+        with sqlite3.connect(db_path) as conn:
+            conn.execute(
+                "CREATE TABLE rates("
+                " symbol TEXT, timeframe INTEGER, time TEXT, close REAL)",
+            )
+            conn.executemany(
+                "INSERT INTO rates(symbol, timeframe, time, close) VALUES (?, ?, ?, ?)",
+                [
+                    ("EURUSD", 1, "2024-01-01T00:00:00+00:00", 1.0),
+                    ("EURUSD", 1, "2024-01-01T00:01:00+00:00", 1.1),
+                ],
+            )
+            create_rate_compatibility_views(conn)
+        targets = build_rate_targets(["EURUSD"], ["M1"])
+        result = load_rate_series_from_sqlite(db_path, targets, count=2)
+        assert set(result) == {("EURUSD", 1)}
+        assert len(result["EURUSD", 1]) == 2
+
+    def test_load_rate_series_reuses_path_connection(
+        self,
+        tmp_path: Path,
+        mocker: MockerFixture,
+    ) -> None:
+        """Test loading from a path opens SQLite once for resolve and reads."""
+        db_path = tmp_path / "single-open-series.db"
+        with sqlite3.connect(db_path) as conn:
+            conn.execute(
+                "CREATE TABLE rates("
+                " symbol TEXT, timeframe INTEGER, time TEXT, close REAL)",
+            )
+            conn.execute(
+                "INSERT INTO rates(symbol, timeframe, time, close) VALUES (?, ?, ?, ?)",
+                ("EURUSD", 1, "2024-01-01T00:00:00+00:00", 1.0),
+            )
+            create_rate_compatibility_views(conn)
+        connect_spy = mocker.spy(history.sqlite3, "connect")
+
+        result = load_rate_series_from_sqlite(
+            db_path,
+            build_rate_targets(["EURUSD"], ["M1"]),
+            count=1,
+        )
+
+        assert set(result) == {("EURUSD", 1)}
+        assert connect_spy.call_count == 1
+
+    def test_load_rate_series_with_explicit_tables(self, tmp_path: Path) -> None:
+        """Test explicit tables and None-symbol targets load series."""
+        db_path = tmp_path / "explicit.db"
+        with sqlite3.connect(db_path) as conn:
+            conn.execute("CREATE TABLE custom_view(time TEXT, close REAL)")
+            conn.execute(
+                "INSERT INTO custom_view(time, close) VALUES (?, ?)",
+                ("2024-01-01T00:00:00+00:00", 1.0),
+            )
+        targets = build_rate_targets([], ["M1"], allow_missing_symbol=True)
+        result = load_rate_series_from_sqlite(
+            db_path,
+            targets,
+            count=1,
+            explicit_tables=["custom_view"],
+        )
+        assert set(result) == {(None, 1)}
+
+    def test_load_rate_series_rejects_non_positive_count(self) -> None:
+        """Test loading requires a positive count."""
+        targets = build_rate_targets(["EURUSD"], ["M1"])
+        with pytest.raises(ValueError, match="count must be positive"):
+            load_rate_series_from_sqlite("unused.db", targets, count=0)
+
+    def test_load_rate_series_rejects_empty_targets(self) -> None:
+        """Test loading requires at least one target before opening SQLite."""
+        with pytest.raises(ValueError, match="At least one rate target"):
+            load_rate_series_from_sqlite("unused.db", [], count=1)
+
+    def test_load_rate_series_requires_symbol_without_explicit_tables(self) -> None:
+        """Test None-symbol targets require explicit tables before opening SQLite."""
+        targets = build_rate_targets([], ["M1"], allow_missing_symbol=True)
+        with pytest.raises(ValueError, match="without a symbol"):
+            load_rate_series_from_sqlite("unused.db", targets, count=1)
+
+    def test_load_rate_series_requires_existing_managed_views(
+        self,
+        tmp_path: Path,
+    ) -> None:
+        """Test loading without explicit tables requires managed rate views."""
+        db_path = tmp_path / "no-managed-views.db"
+        with sqlite3.connect(db_path) as conn:
+            conn.execute(
+                "CREATE TABLE rates("
+                " symbol TEXT, timeframe INTEGER, time TEXT, close REAL)",
+            )
+            conn.execute(
+                "INSERT INTO rates(symbol, timeframe, time, close) VALUES (?, ?, ?, ?)",
+                ("EURUSD", 1, "2024-01-01T00:00:00+00:00", 1.0),
+            )
+        targets = build_rate_targets(["EURUSD"], ["M1"])
+        with pytest.raises(ValueError, match="No rate compatibility view exists"):
+            load_rate_series_from_sqlite(db_path, targets, count=1)
+
+    def test_load_rate_series_rejects_duplicate_targets(self) -> None:
+        """Test duplicate (symbol, timeframe) targets are rejected."""
+        targets = [
+            RateTarget("EURUSD", 1),
+            RateTarget("EURUSD", "M1"),
+        ]
+        with pytest.raises(ValueError, match=r"Duplicate rate target: \('EURUSD', 1\)"):
+            load_rate_series_from_sqlite("unused.db", targets, count=1)
+
+    def test_load_rate_series_rejects_duplicate_targets_with_explicit_tables(
+        self,
+        tmp_path: Path,
+    ) -> None:
+        """Test duplicate targets are rejected even with explicit tables."""
+        db_path = tmp_path / "duplicate-explicit.db"
+        with sqlite3.connect(db_path) as conn:
+            conn.execute("CREATE TABLE custom_view(time TEXT, close REAL)")
+            conn.execute(
+                "INSERT INTO custom_view(time, close) VALUES (?, ?)",
+                ("2024-01-01T00:00:00+00:00", 1.0),
+            )
+        targets = [
+            RateTarget("EURUSD", 1),
+            RateTarget("EURUSD", 1),
+        ]
+        with pytest.raises(ValueError, match=r"Duplicate rate target: \('EURUSD', 1\)"):
+            load_rate_series_from_sqlite(
+                db_path,
+                targets,
+                count=1,
+                explicit_tables=["custom_view", "custom_view"],
+            )

tests/test_sdk.py

@@ -15,16 +15,18 @@ from pytest_mock import MockerFixture  # noqa: TC002
 if TYPE_CHECKING:
     from pathlib import Path
 
-    from pdmt5 import Mt5DataClient
+    from pdmt5 import Mt5Config, Mt5DataClient
 
 from mt5cli import sdk
 from mt5cli.history import DEFAULT_HISTORY_TIMEFRAMES
 from mt5cli.sdk import (
+    AccountSpec,
     Mt5CliClient,
     account_info,
     build_config,
     collect_history,
     collect_latest_rates,
+    collect_latest_rates_for_accounts,
     copy_rates_from,
     copy_rates_from_pos,
     copy_rates_range,
@@ -36,6 +38,7 @@ from mt5cli.sdk import (
     latest_rates,
     market_book,
     minimum_margins,
+    mt5_session,
     mt5_summary,
     mt5_summary_as_df,
     orders,
@@ -1248,3 +1251,177 @@ class TestMinimumMargins:
         )
         client.order_calc_margin.assert_any_call(0, "EURUSD", 0.01, 1.1010)
         client.order_calc_margin.assert_any_call(1, "EURUSD", 0.01, 1.1000)
+
+
+class TestMt5Session:
+    """Tests for the mt5_session context manager."""
+
+    def test_yields_connected_client_and_shuts_down(
+        self,
+        mocker: MockerFixture,
+    ) -> None:
+        """Test mt5_session connects, yields a client wrapper, and shuts down."""
+        mock_client = MagicMock()
+        mt5_data_client = mocker.patch(
+            "mt5cli.sdk.Mt5DataClient",
+            return_value=mock_client,
+        )
+
+        with mt5_session(build_config(path="/opt/mt5/terminal64.exe")) as client:
+            mock_client.initialize_and_login_mt5.assert_called_once()
+            assert isinstance(client, Mt5CliClient)
+
+        config = mt5_data_client.call_args.kwargs["config"]
+        assert config.path == "/opt/mt5/terminal64.exe"
+        mock_client.shutdown.assert_called_once()
+
+    def test_default_config_attaches_to_running_terminal(
+        self,
+        mocker: MockerFixture,
+    ) -> None:
+        """Test mt5_session builds a default config when none is supplied."""
+        mock_client = MagicMock()
+        mt5_data_client = mocker.patch(
+            "mt5cli.sdk.Mt5DataClient",
+            return_value=mock_client,
+        )
+
+        with mt5_session():
+            pass
+
+        mt5_data_client.assert_called_once()
+        mock_client.shutdown.assert_called_once()
+
+
+class TestAccountSpec:
+    """Tests for account configuration helpers."""
+
+    def test_repr_omits_password(self) -> None:
+        """Test AccountSpec repr does not expose plaintext passwords."""
+        spec = AccountSpec(symbols=["EURUSD"], login=123, password="secret")
+
+        assert "secret" not in repr(spec)
+        assert "password" not in repr(spec)
+
+    @pytest.mark.parametrize(
+        ("login", "expected"),
+        [
+            (None, None),
+            (123, 123),
+            ("", None),
+            ("   ", None),
+            ("456", 456),
+        ],
+    )
+    def test_coerce_login(
+        self,
+        login: int | str | None,
+        expected: int | None,
+    ) -> None:
+        """Test login values are normalized for account configs."""
+        assert sdk._coerce_login(login) == expected  # type: ignore[reportPrivateUsage]
+
+    def test_coerce_login_rejects_non_numeric_string(self) -> None:
+        """Test non-numeric login strings raise ValueError."""
+        with pytest.raises(ValueError, match="invalid literal"):
+            sdk._coerce_login("abc")  # type: ignore[reportPrivateUsage]
+
+
+class TestCollectLatestRatesForAccounts:
+    """Tests for collect_latest_rates_for_accounts."""
+
+    def test_merges_results_across_accounts(
+        self,
+        mock_client: MagicMock,
+        mocker: MockerFixture,
+    ) -> None:
+        """Test rates are collected and merged for each account group."""
+        mt5_data_client = mocker.patch(
+            "mt5cli.sdk.Mt5DataClient",
+            return_value=mock_client,
+        )
+        accounts = [
+            AccountSpec(symbols=["EURUSD"], login="123"),
+            AccountSpec(symbols=["GBPUSD"], login=456),
+        ]
+
+        result = collect_latest_rates_for_accounts(accounts, ["M1"], count=2)
+
+        assert set(result) == {("EURUSD", 1), ("GBPUSD", 1)}
+        assert mt5_data_client.call_count == 2
+        assert mock_client.initialize_and_login_mt5.call_count == 2
+        assert mock_client.shutdown.call_count == 2
+
+    def test_builds_config_from_account_and_base(
+        self,
+        mock_client: MagicMock,
+        mocker: MockerFixture,
+    ) -> None:
+        """Test account fields override base_config, empty login falls back."""
+        configs: list[object] = []
+
+        def _record_config(*, config: object) -> MagicMock:
+            configs.append(config)
+            return mock_client
+
+        mocker.patch("mt5cli.sdk.Mt5DataClient", side_effect=_record_config)
+        base = build_config(login=999, server="Base-Server", timeout=5000)
+        accounts = [
+            AccountSpec(symbols=["EURUSD"], login="", server="Acct-Server"),
+        ]
+
+        collect_latest_rates_for_accounts(accounts, ["M1"], count=1, base_config=base)
+
+        assert len(configs) == 1
+        config = cast("Mt5Config", configs[0])
+        assert config.login == 999
+        assert config.server == "Acct-Server"
+        assert config.timeout == 5000
+
+    @pytest.mark.parametrize(
+        ("accounts", "timeframes", "count", "match"),
+        [
+            ([], ["M1"], 1, "At least one account"),
+            ([AccountSpec(symbols=["EURUSD"])], [], 1, "At least one timeframe"),
+            (
+                [AccountSpec(symbols=[])],
+                ["M1"],
+                1,
+                "Each account requires at least one symbol",
+            ),
+            (
+                [AccountSpec(symbols=["EURUSD"])],
+                ["M1"],
+                0,
+                "count must be positive",
+            ),
+        ],
+    )
+    def test_rejects_invalid_inputs(
+        self,
+        accounts: list[AccountSpec],
+        timeframes: list[str],
+        count: int,
+        match: str,
+    ) -> None:
+        """Test input validation for account-level rate collection."""
+        with pytest.raises(ValueError, match=match):
+            collect_latest_rates_for_accounts(accounts, timeframes, count)
+
+    def test_rejects_empty_symbols_before_connecting(
+        self,
+        mocker: MockerFixture,
+    ) -> None:
+        """Test all account symbols are validated before any MT5 connection."""
+        mt5_data_client = mocker.patch("mt5cli.sdk.Mt5DataClient")
+        accounts = [
+            AccountSpec(symbols=["EURUSD"], login=123),
+            AccountSpec(symbols=[], login=456),
+        ]
+
+        with pytest.raises(
+            ValueError, match="Each account requires at least one symbol"
+        ):
+            collect_latest_rates_for_accounts(accounts, ["M1"], count=1)
+
+        mt5_data_client.assert_not_called()

uv.lock

@@ -487,7 +487,7 @@ wheels = [
 
 [[package]]
 name = "mt5cli"
-version = "0.5.0"
+version = "0.5.2"
 source = { editable = "." }
 dependencies = [
     { name = "click" },