diff --git a/agent_assembly/__init__.py b/agent_assembly/__init__.py
index 3a8491e4..7d901a9f 100644
--- a/agent_assembly/__init__.py
+++ b/agent_assembly/__init__.py
@@ -12,9 +12,10 @@
     PolicyError,
     ToolExecutionBlockedError,
 )
+from agent_assembly.types import AuditEvent, CallStackNode, CallStackNodeKind
 
 try:
-    from agent_assembly._core import (  # type: ignore[attr-defined]
+    from agent_assembly._core import (
         GovernanceEvent,
         PolicyResult,
         PolicyTimeoutError,
@@ -39,6 +40,9 @@
     "AdapterValidationError",
     "ToolExecutionBlockedError",
     "MCPToolBlockedError",
+    "AuditEvent",
+    "CallStackNode",
+    "CallStackNodeKind",
 ]
 
 if "RuntimeClient" in globals():
diff --git a/agent_assembly/types.py b/agent_assembly/types.py
index e0a41989..01d60b74 100644
--- a/agent_assembly/types.py
+++ b/agent_assembly/types.py
@@ -16,9 +16,95 @@
 
 from __future__ import annotations
 
+from dataclasses import dataclass, field
+from typing import Literal
+
+# ── Event types (AAASM-1435) ──────────────────────────────────────────────────
+
+CallStackNodeKind = Literal["llm", "tool", "result"]
+"""Discriminator for a [`CallStackNode`] — open-ended on the wire (proto uses
+`string kind`) but typed here as a `Literal` for the three values the
+dashboard currently renders."""
+
+
+@dataclass(frozen=True, slots=True)
+class CallStackNode:
+    """One node in the hierarchical call stack attached to an [`AuditEvent`].
+
+    Mirrors the proto `assembly.audit.v1.CallStackNode` message added in
+    AAASM-1419. Field names match the wire-protocol's snake_case so the
+    dataclass can be constructed directly from a decoded payload without an
+    intermediate naming transform.
+
+    Attributes:
+        id: Stable identifier for this node within the call stack.
+        kind: Node category — one of ``"llm"``, ``"tool"``, or ``"result"``.
+        label: Human-readable label rendered by downstream UI.
+        latency_ms: Step-local latency in milliseconds, or `None` when the
+            producer did not record a duration.
+        children: Recursive descent — nested calls produced by this step.
+            Empty list (default) when the node has no children.
+    """
+
+    id: str
+    kind: CallStackNodeKind
+    label: str
+    latency_ms: int | None = None
+    children: list[CallStackNode] = field(default_factory=list)
+
+
+@dataclass(frozen=True, slots=True)
+class AuditEvent:
+    """A single governance-relevant occurrence in the gateway audit trail.
+
+    Python-friendly subset of the proto `assembly.audit.v1.AuditEvent`
+    message. Field names match the wire-protocol's snake_case so the
+    dataclass can be constructed directly from a decoded payload.
+
+    Out of scope today (tracked under separate follow-up Tasks):
+      * The ``detail`` oneof (`LLMCallDetail` / `ToolCallDetail` /
+        `FileOpDetail` / `NetworkCallDetail` / `ProcessExecDetail` /
+        `PolicyViolation` / `ApprovalEvent`).
+      * The lineage block (`root_agent_id`, `parent_agent_id`, `team_id`,
+        `session_id`, `delegation_reason`, `spawned_by_tool`, `depth`).
+
+    This class exists today to surface the new ``call_stack`` field added
+    by AAASM-1419 to SDK consumers. Round-tripping into the gateway via the
+    wire encoder remains the Rust FFI layer's responsibility.
+
+    Attributes:
+        event_id: Unique identifier for this audit record (UUID v7).
+        agent_id: Identity string of the agent that produced this event.
+        action_type: High-level action category (e.g. ``"llm_call"``,
+            ``"tool_call"``, ``"file_op"``). Open-ended on the wire.
+        decision: Policy engine verdict (e.g. ``"allow"``, ``"deny"``,
+            ``"redact"``).
+        trace_id: Distributed tracing run-level identifier. Empty when
+            unset.
+        span_id: Distributed tracing action-level identifier. Empty when
+            unset.
+        parent_span_id: Distributed tracing parent span identifier. Empty
+            when this is a root span.
+        labels: Arbitrary key/value labels attached at event creation.
+        call_stack: Hierarchical record of LLM / tool / result steps that
+            led to this event. Empty list (default) when the producer did
+            not record a stack. Renders inline beneath an expanded Live
+            Ops row in the dashboard.
+    """
+
+    event_id: str
+    agent_id: str
+    action_type: str
+    decision: str
+    trace_id: str = ""
+    span_id: str = ""
+    parent_span_id: str = ""
+    labels: dict[str, str] = field(default_factory=dict)
+    call_stack: list[CallStackNode] = field(default_factory=list)
+
+
 __all__ = [
-    "AgentId",
-    "PolicyId",
-    "AssemblyId",
-    "ConfigDict",
+    "AuditEvent",
+    "CallStackNode",
+    "CallStackNodeKind",
 ]
diff --git a/rust/aa-ffi-python/Cargo.toml b/rust/aa-ffi-python/Cargo.toml
index 1cff3d24..b716d9fc 100644
--- a/rust/aa-ffi-python/Cargo.toml
+++ b/rust/aa-ffi-python/Cargo.toml
@@ -10,8 +10,8 @@ name = "aa_ffi_python"
 crate-type = ["cdylib"]
 
 [dependencies]
-aa-core = { git = "https://github.com/AI-agent-assembly/agent-assembly.git", package = "aa-core", features = ["serde"] }
-aa-proto = { git = "https://github.com/AI-agent-assembly/agent-assembly.git", package = "aa-proto" }
+aa-core = { git = "https://github.com/AI-agent-assembly/agent-assembly.git", rev = "ed4aa11a8c1d1ce1e6f96b08cf2179fd772099b2", package = "aa-core", features = ["serde"] }
+aa-proto = { git = "https://github.com/AI-agent-assembly/agent-assembly.git", rev = "ed4aa11a8c1d1ce1e6f96b08cf2179fd772099b2", package = "aa-proto" }
 once_cell = "1.20"
 prost = "0.14"
 pyo3 = { version = "0.20", features = ["extension-module"] }
diff --git a/test/unit/test_types_audit_event.py b/test/unit/test_types_audit_event.py
new file mode 100644
index 00000000..23fd7eb9
--- /dev/null
+++ b/test/unit/test_types_audit_event.py
@@ -0,0 +1,98 @@
+"""Unit tests for the `agent_assembly.types` dataclasses (AAASM-1435).
+
+Covers `AuditEvent` + `CallStackNode` — the Python-friendly mirrors of
+the proto messages added in AAASM-1419.
+"""
+
+from __future__ import annotations
+
+import dataclasses
+
+import pytest
+
+from agent_assembly import AuditEvent, CallStackNode
+
+
+def test_call_stack_node_required_fields() -> None:
+    node = CallStackNode(id="n0", kind="llm", label="gpt-4o")
+    assert node.id == "n0"
+    assert node.kind == "llm"
+    assert node.label == "gpt-4o"
+    assert node.latency_ms is None
+    assert node.children == []
+
+
+def test_call_stack_node_with_latency_and_children() -> None:
+    child = CallStackNode(id="n1", kind="tool", label="gmail.send", latency_ms=120)
+    parent = CallStackNode(id="n0", kind="llm", label="gpt-4o", latency_ms=300, children=[child])
+    assert parent.children[0] is child
+    assert parent.children[0].latency_ms == 120
+
+
+def test_call_stack_node_is_frozen() -> None:
+    node = CallStackNode(id="n0", kind="llm", label="gpt-4o")
+    with pytest.raises(dataclasses.FrozenInstanceError):
+        node.id = "n2"  # type: ignore[misc]
+
+
+def test_audit_event_minimal_construction_defaults_call_stack_to_empty() -> None:
+    event = AuditEvent(
+        event_id="evt-1",
+        agent_id="support-agent",
+        action_type="llm_call",
+        decision="allow",
+    )
+    assert event.call_stack == []
+    assert event.labels == {}
+    assert event.trace_id == ""
+    assert event.span_id == ""
+    assert event.parent_span_id == ""
+
+
+def test_audit_event_with_populated_call_stack_tree() -> None:
+    stack = [
+        CallStackNode(
+            id="n0",
+            kind="llm",
+            label="gpt-4o",
+            latency_ms=300,
+            children=[
+                CallStackNode(
+                    id="n1",
+                    kind="tool",
+                    label="gmail.send",
+                    latency_ms=120,
+                    children=[
+                        CallStackNode(id="n2", kind="result", label="200 OK"),
+                    ],
+                ),
+            ],
+        ),
+    ]
+    event = AuditEvent(
+        event_id="evt-1",
+        agent_id="support-agent",
+        action_type="llm_call",
+        decision="allow",
+        trace_id="trace-1",
+        span_id="span-1",
+        call_stack=stack,
+    )
+    assert event.call_stack[0].kind == "llm"
+    assert event.call_stack[0].children[0].label == "gmail.send"
+    assert event.call_stack[0].children[0].children[0].kind == "result"
+    assert event.call_stack[0].children[0].children[0].latency_ms is None
+
+
+def test_audit_event_is_frozen() -> None:
+    event = AuditEvent(event_id="e", agent_id="a", action_type="llm_call", decision="allow")
+    with pytest.raises(dataclasses.FrozenInstanceError):
+        event.event_id = "e2"  # type: ignore[misc]
+
+
+def test_top_level_imports_resolve_to_types_module() -> None:
+    from agent_assembly.types import AuditEvent as TypesAuditEvent
+    from agent_assembly.types import CallStackNode as TypesCallStackNode
+
+    assert AuditEvent is TypesAuditEvent
+    assert CallStackNode is TypesCallStackNode