feat: implement message and communication domain models

CLAUDE.md

@@ -41,6 +41,10 @@ src/ai_company/
   tools/          # Tool registry, MCP integration, role-based access
 ```
 
+## Shell Usage
+
+- **NEVER use `cd` in Bash commands** — the working directory is already set to the project root. Use absolute paths or run commands directly. Do NOT prefix commands with `cd C:/Users/Aurelio/ai-company &&`.
+
 ## Code Conventions
 
 - **No `from __future__ import annotations`** — Python 3.14 has PEP 649

src/ai_company/communication/__init__.py

@@ -0,0 +1,43 @@
+"""Communication domain models for the AI company framework."""
+
+from ai_company.communication.channel import Channel
+from ai_company.communication.config import (
+    CircuitBreakerConfig,
+    CommunicationConfig,
+    HierarchyConfig,
+    LoopPreventionConfig,
+    MeetingsConfig,
+    MeetingTypeConfig,
+    MessageBusConfig,
+    RateLimitConfig,
+)
+from ai_company.communication.enums import (
+    AttachmentType,
+    ChannelType,
+    CommunicationPattern,
+    MessageBusBackend,
+    MessagePriority,
+    MessageType,
+)
+from ai_company.communication.message import Attachment, Message, MessageMetadata
+
+__all__ = [
+    "Attachment",
+    "AttachmentType",
+    "Channel",
+    "ChannelType",
+    "CircuitBreakerConfig",
+    "CommunicationConfig",
+    "CommunicationPattern",
+    "HierarchyConfig",
+    "LoopPreventionConfig",
+    "MeetingTypeConfig",
+    "MeetingsConfig",
+    "Message",
+    "MessageBusBackend",
+    "MessageBusConfig",
+    "MessageMetadata",
+    "MessagePriority",
+    "MessageType",
+    "RateLimitConfig",
+]

src/ai_company/communication/channel.py

@@ -0,0 +1,39 @@
+"""Channel domain model."""
+
+from typing import Self
+
+from pydantic import BaseModel, ConfigDict, Field, model_validator
+
+from ai_company.communication.enums import ChannelType
+from ai_company.core.types import (
+    NotBlankStr,
+    validate_non_blank_unique_strings,
+)
+
+
+class Channel(BaseModel):
+    """A named communication channel that agents can subscribe to.
+
+    Attributes:
+        name: Channel name (e.g. ``"#engineering"``).
+        type: Channel delivery semantics.
+        subscribers: Agent IDs subscribed to this channel.
+    """
+
+    model_config = ConfigDict(frozen=True)
+
+    name: NotBlankStr = Field(description="Channel name")
+    type: ChannelType = Field(
+        default=ChannelType.TOPIC,
+        description="Channel delivery semantics",
+    )
+    subscribers: tuple[str, ...] = Field(
+        default=(),
+        description="Agent IDs subscribed to this channel",
+    )
+
+    @model_validator(mode="after")
+    def _validate_subscribers(self) -> Self:
+        """Ensure subscriber entries are non-blank and unique."""
+        validate_non_blank_unique_strings(self.subscribers, "subscribers")
+        return self

src/ai_company/communication/config.py

@@ -0,0 +1,283 @@
+"""Communication configuration models (DESIGN_SPEC Sections 5.4, 5.5)."""
+
+from collections import Counter
+from typing import Literal, Self
+
+from pydantic import BaseModel, ConfigDict, Field, model_validator
+
+from ai_company.communication.enums import (
+    CommunicationPattern,
+    MessageBusBackend,
+)
+from ai_company.core.types import (
+    NotBlankStr,
+    validate_non_blank_unique_strings,
+)
+
+# Default channels from DESIGN_SPEC Section 5.4.
+_DEFAULT_CHANNELS: tuple[str, ...] = (
+    "#all-hands",
+    "#engineering",
+    "#product",
+    "#design",
+    "#incidents",
+    "#code-review",
+    "#watercooler",
+)
+
+
+class MessageBusConfig(BaseModel):
+    """Message bus backend configuration.
+
+    Maps to DESIGN_SPEC Section 5.4 ``message_bus``.
+
+    Attributes:
+        backend: Transport backend to use.
+        channels: Pre-defined channel names.
+    """
+
+    model_config = ConfigDict(frozen=True)
+
+    backend: MessageBusBackend = Field(
+        default=MessageBusBackend.INTERNAL,
+        description="Transport backend",
+    )
+    channels: tuple[str, ...] = Field(
+        default=_DEFAULT_CHANNELS,
+        description="Pre-defined channel names",
+    )
+
+    @model_validator(mode="after")
+    def _validate_channels(self) -> Self:
+        """Ensure channel names are non-blank and unique."""
+        validate_non_blank_unique_strings(self.channels, "channels")
+        return self
+
+
+class MeetingTypeConfig(BaseModel):
+    """Configuration for a single meeting type.
+
+    Maps to DESIGN_SPEC Section 5.4 ``meetings.types[]``.  Exactly one of
+    ``frequency`` or ``trigger`` must be set.
+
+    Attributes:
+        name: Meeting type name (e.g. ``"daily_standup"``).
+        frequency: Recurrence schedule (mutually exclusive with trigger).
+        trigger: Event trigger (mutually exclusive with frequency).
+        participants: Participant role or agent identifiers.
+        duration_tokens: Token budget for the meeting.
+    """
+
+    model_config = ConfigDict(frozen=True)
+
+    name: NotBlankStr = Field(description="Meeting type name")
+    frequency: NotBlankStr | None = Field(
+        default=None,
+        description="Recurrence schedule",
+    )
+    trigger: NotBlankStr | None = Field(
+        default=None,
+        description="Event trigger",
+    )
+    participants: tuple[str, ...] = Field(
+        default=(),
+        description="Participant role or agent identifiers",
+    )
+    duration_tokens: int = Field(
+        default=2000,
+        gt=0,
+        description="Token budget for the meeting",
+    )
+
+    @model_validator(mode="after")
+    def _validate_frequency_or_trigger(self) -> Self:
+        """Exactly one of frequency or trigger must be set."""
+        if self.frequency is not None and self.trigger is not None:
+            msg = "Only one of frequency or trigger may be set, not both"
+            raise ValueError(msg)
+        if self.frequency is None and self.trigger is None:
+            msg = "Exactly one of frequency or trigger must be set"
+            raise ValueError(msg)
+        return self
+
+    @model_validator(mode="after")
+    def _validate_participants(self) -> Self:
+        """Ensure participant entries are non-blank and unique."""
+        validate_non_blank_unique_strings(self.participants, "participants")
+        return self
+
+
+class MeetingsConfig(BaseModel):
+    """Meetings subsystem configuration.
+
+    Maps to DESIGN_SPEC Section 5.4 ``meetings``.
+
+    Attributes:
+        enabled: Whether the meetings subsystem is active.
+        types: Configured meeting types (unique by name).
+    """
+
+    model_config = ConfigDict(frozen=True)
+
+    enabled: bool = Field(default=True, description="Meetings subsystem active")
+    types: tuple[MeetingTypeConfig, ...] = Field(
+        default=(),
+        description="Configured meeting types",
+    )
+
+    @model_validator(mode="after")
+    def _validate_unique_meeting_names(self) -> Self:
+        """Ensure meeting type names are unique."""
+        names = [mt.name for mt in self.types]
+        if len(names) != len(set(names)):
+            dupes = sorted(n for n, c in Counter(names).items() if c > 1)
+            msg = f"Duplicate meeting type names: {dupes}"
+            raise ValueError(msg)
+        return self
+
+
+class HierarchyConfig(BaseModel):
+    """Hierarchy enforcement configuration.
+
+    Maps to DESIGN_SPEC Section 5.4 ``hierarchy``.
+
+    Attributes:
+        enforce_chain_of_command: Whether chain-of-command is enforced.
+        allow_skip_level: Whether skip-level messaging is allowed.
+    """
+
+    model_config = ConfigDict(frozen=True)
+
+    enforce_chain_of_command: bool = Field(
+        default=True,
+        description="Enforce chain-of-command",
+    )
+    allow_skip_level: bool = Field(
+        default=False,
+        description="Allow skip-level messaging",
+    )
+
+
+class RateLimitConfig(BaseModel):
+    """Per-pair message rate limit configuration.
+
+    Maps to DESIGN_SPEC Section 5.5 ``rate_limit``.
+
+    Attributes:
+        max_per_pair_per_minute: Maximum messages per agent pair per minute.
+        burst_allowance: Extra burst capacity above the rate limit.
+    """
+
+    model_config = ConfigDict(frozen=True)
+
+    max_per_pair_per_minute: int = Field(
+        default=10,
+        gt=0,
+        description="Max messages per agent pair per minute",
+    )
+    burst_allowance: int = Field(
+        default=3,
+        ge=0,
+        description="Extra burst capacity",
+    )
+
+
+class CircuitBreakerConfig(BaseModel):
+    """Circuit breaker configuration for agent-pair communication.
+
+    Maps to DESIGN_SPEC Section 5.5 ``circuit_breaker``.
+
+    Attributes:
+        bounce_threshold: Bounce count before the circuit opens.
+        cooldown_seconds: Seconds to wait before retrying after trip.
+    """
+
+    model_config = ConfigDict(frozen=True)
+
+    bounce_threshold: int = Field(
+        default=3,
+        gt=0,
+        description="Bounce count before circuit opens",
+    )
+    cooldown_seconds: int = Field(
+        default=300,
+        gt=0,
+        description="Cooldown period in seconds",
+    )
+
+
+class LoopPreventionConfig(BaseModel):
+    """Loop prevention safeguards.
+
+    Maps to DESIGN_SPEC Section 5.5.  ``ancestry_tracking`` is always on
+    and cannot be disabled.
+
+    Attributes:
+        max_delegation_depth: Hard limit on delegation chain length.
+        rate_limit: Per-pair rate limit settings.
+        dedup_window_seconds: Deduplication window in seconds.
+        circuit_breaker: Circuit breaker settings.
+        ancestry_tracking: Must always be ``True``.
+    """
+
+    model_config = ConfigDict(frozen=True)
+
+    max_delegation_depth: int = Field(
+        default=5,
+        gt=0,
+        description="Hard limit on delegation chain length",
+    )
+    rate_limit: RateLimitConfig = Field(
+        default_factory=RateLimitConfig,
+        description="Per-pair rate limit settings",
+    )
+    dedup_window_seconds: int = Field(
+        default=60,
+        gt=0,
+        description="Deduplication window in seconds",
+    )
+    circuit_breaker: CircuitBreakerConfig = Field(
+        default_factory=CircuitBreakerConfig,
+        description="Circuit breaker settings",
+    )
+    ancestry_tracking: Literal[True] = Field(
+        default=True,
+        description="Task ancestry tracking (always on, not configurable)",
+    )
+
+
+class CommunicationConfig(BaseModel):
+    """Top-level communication configuration.
+
+    Aggregates DESIGN_SPEC Sections 5.4 and 5.5 under a single model.
+
+    Attributes:
+        default_pattern: High-level communication pattern.
+        message_bus: Message bus configuration.
+        meetings: Meetings subsystem configuration.
+        hierarchy: Hierarchy enforcement settings.
+        loop_prevention: Loop prevention safeguards.
+    """
+
+    model_config = ConfigDict(frozen=True)
+
+    default_pattern: CommunicationPattern = Field(
+        default=CommunicationPattern.HYBRID,
+        description="High-level communication pattern",
+    )
+    message_bus: MessageBusConfig = Field(
+        default_factory=MessageBusConfig,
+        description="Message bus configuration",
+    )
+    meetings: MeetingsConfig = Field(
+        default_factory=MeetingsConfig,
+        description="Meetings subsystem configuration",
+    )
+    hierarchy: HierarchyConfig = Field(
+        default_factory=HierarchyConfig,
+        description="Hierarchy enforcement settings",
+    )
+    loop_prevention: LoopPreventionConfig = Field(
+        default_factory=LoopPreventionConfig,
+        description="Loop prevention safeguards",
+    )