diff --git a/README.md b/README.md
index b5c7bc1..4b17eb3 100644
--- a/README.md
+++ b/README.md
@@ -21,4 +21,11 @@ Roadmap highlights
 - Phase 3: HIL/mobile pilot and performance benchmarks
 - Phase 4: governance and adapter marketplace
 
-If you'd like a minimal DSL sketch or a toy adapter, I can draft one here.
+DSL Sketch (Minimal)
+
+- LocalProblem: id, assets, objective, constraints, signals
+- SharedSignal: named data channels carrying signals between blocks
+- DSLPlanDelta: versioned incremental plan changes with timestamp and author
+- DSLDualVariables: simple container for Lagrange multipliers
+
+This DSL sketch is implemented in the package at src/algograph_algebraic_portfolio_compiler_f/dsl.py and can be used to bootstrap a portable, algebraic graph representation for edge deployments.
diff --git a/src/algograph_algebraic_portfolio_compiler_f/adapters.py b/src/algograph_algebraic_portfolio_compiler_f/adapters.py
index 4e26c96..161b03f 100644
--- a/src/algograph_algebraic_portfolio_compiler_f/adapters.py
+++ b/src/algograph_algebraic_portfolio_compiler_f/adapters.py
@@ -23,4 +23,21 @@ class VenueAdapter:
         return None
 
 
-__all__ = ["VenueAdapter"]
+@dataclass
+class ToyVenueAdapter(VenueAdapter):
+    """Toy venue adapter for bootstrap/demo purposes."""
+
+    def __init__(self) -> None:
+        super().__init__(name="ToyVenue", endpoint="https://toy.local/api", credentials=None)
+
+    # In a real adapter this would fetch live signals.
+    def fetch_signal(self, symbol: str) -> Any:
+        return 1.0  # deterministic placeholder
+
+
+def create_toy_venue_adapter() -> ToyVenueAdapter:
+    """Factory helper to instantiate a toy venue adapter."""
+    return ToyVenueAdapter()
+
+
+__all__ = ["VenueAdapter", "ToyVenueAdapter", "create_toy_venue_adapter"]
diff --git a/src/algograph_algebraic_portfolio_compiler_f/dsl.py b/src/algograph_algebraic_portfolio_compiler_f/dsl.py
new file mode 100644
index 0000000..294afe5
--- /dev/null
+++ b/src/algograph_algebraic_portfolio_compiler_f/dsl.py
@@ -0,0 +1,62 @@
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from typing import Any, Dict, List, Optional
+
+
+@dataclass
+class LocalProblem:
+    """Canonical local portfolio block in the DSL.
+
+    Attributes:
+      id: unique identifier for the block
+      assets: list of asset identifiers
+      objective: algebraic description (linear/quadratic, etc.)
+      constraints: list of constraint descriptors
+      signals: map of propagated signals (optional)
+    """
+
+    id: str
+    assets: List[str]
+    objective: Dict[str, Any]
+    constraints: List[Dict[str, Any]] = field(default_factory=list)
+    signals: Dict[str, Any] = field(default_factory=dict)
+
+    def add_signal(self, key: str, value: Any) -> None:
+        self.signals[key] = value
+
+
+@dataclass
+class SharedSignal:
+    """Represents a data channel carrying signals between blocks."""
+
+    name: str
+    payload: Dict[str, Any] = field(default_factory=dict)
+
+    def push(self, key: str, value: Any) -> None:
+        self.payload[key] = value
+
+
+@dataclass
+class DSLPlanDelta:
+    """Incremental plan changes with versioning metadata."""
+
+    delta: Dict[str, Any]
+    version: int
+    timestamp: float
+    author: Optional[str] = None
+    contract_id: Optional[str] = None
+    privacy_budget: Optional[Dict[str, Any]] = None
+
+
+@dataclass
+class DSLDualVariables:
+    """Optimization coupling multipliers (e.g., prices/penalties)."""
+
+    multipliers: Dict[str, float] = field(default_factory=dict)
+
+    def update(self, key: str, value: float) -> None:
+        self.multipliers[key] = float(value)
+
+
+__all__ = ["LocalProblem", "SharedSignal", "DSLPlanDelta", "DSLDualVariables"]