diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..bd5590b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,21 @@
+node_modules/
+.npmrc
+.env
+.env.*
+__tests__/
+coverage/
+.nyc_output/
+dist/
+build/
+.cache/
+*.log
+.DS_Store
+tmp/
+.tmp/
+__pycache__/
+*.pyc
+.venv/
+venv/
+*.egg-info/
+.pytest_cache/
+READY_TO_PUBLISH
diff --git a/AGENTS.md b/AGENTS.md
new file mode 100644
index 0000000..0180002
--- /dev/null
+++ b/AGENTS.md
@@ -0,0 +1,20 @@
+# AGENTS.md
+
+Architecture and rules for this repository (CatOpt-Query - MVP)
+
+- Tech stack: Python 3.9+, plain dataclasses for protocol modeling, minimal pure-Python adapters.
+- Testing: pytest-based unit tests.
+- Packaging: pyproject.toml with setuptools build backend. README.md hooks into packaging.
+- Development rules:
+  - Do not add backward-incompatible changes unless explicitly required.
+  - Tests must pass before publishing (test.sh will enforce this).
+  - Commit messages are not automated here; use descriptive messages when you commit outside of this environment.
+- File layout:
+  - catopt_query/: library code (protocol models, core, adapters).
+  - tests/: unit tests.
+  - README.md, AGENTS.md: project docs and governance.
+
+- MVP goals and acceptance:
+  - Protocol modelling correctness (LocalProblem, SharedVariables, etc.).
+  - Canonical representation and adapter mapping exist and are testable.
+  - Packaging builds and tests pass.
diff --git a/README.md b/README.md
index 8bade05..b17262e 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,23 @@
-# catopt-query-category-theoretic-composit
+CatOpt-Query: MVP scaffolding for a category-theoretic distributed query planning framework.
 
-Problem space: Distributed databases across shards and heterogeneous storage backends (relational, document, time-series) struggle with cross-shard queries, join planning, and pushdown optimization under varying data locality and bandwidth constraint
\ No newline at end of file
+Overview
+- A minimal, production-oriented Python MVP that models local shard plans (Objects), inter-shard signals (Morphisms), and vendor adapters (Functors).
+- Includes a canonical representation, two starter adapters (PostgreSQL and MongoDB), and a simple coordinator to fuse local plans.
+- Designed as a stepping stone toward the 8–12 week MVP plan described in the project proposal.
+
+What you’ll find here
+- Core data models for LocalProblem, SharedVariables, DualVariables, PlanDelta, DataContract, and AuditLog.
+- A CanonicalPlan representation and a naive joint-planning coordinator.
+- Adapters for PostgreSQL and MongoDB that map local plans to the canonical representation.
+- Tests validating protocol serialization, adapter mappings, and basic joint planning behavior.
+- A lightweight protocol registry (Graph-of-Contracts concept) skeleton and a small DSL skeleton (data classes-only).
+
+Getting started
+- Install: python3 -m build && pip install dist/catopt_query-0.1.0-py3-none-any.whl
+- Run tests: pytest -q
+
+Notes
+- This is an MVP scaffold. It focuses on correctness, testability, and incremental extensibility for the larger CatOpt-Query project.
+- No external DB calls are required for the MVP tests; adapters simulate plan mapping.
+
+License: MIT
diff --git a/catopt_query/__init__.py b/catopt_query/__init__.py
new file mode 100644
index 0000000..e3bb8f2
--- /dev/null
+++ b/catopt_query/__init__.py
@@ -0,0 +1,18 @@
+from .protocol import LocalProblem, SharedVariables, DualVariables, PlanDelta, DataContract, AuditLog
+from .core import CanonicalPlan, aggregate_joint_plan, map_local_to_canonical
+from .adapters.postgres_adapter import map_postgres_to_canonical
+from .adapters.mongo_adapter import map_mongo_to_canonical
+
+__all__ = [
+    "LocalProblem",
+    "SharedVariables",
+    "DualVariables",
+    "PlanDelta",
+    "DataContract",
+    "AuditLog",
+    "CanonicalPlan",
+    "aggregate_joint_plan",
+    "map_local_to_canonical",
+    "map_postgres_to_canonical",
+    "map_mongo_to_canonical",
+]
diff --git a/catopt_query/adapters/__init__.py b/catopt_query/adapters/__init__.py
new file mode 100644
index 0000000..d8b82ed
--- /dev/null
+++ b/catopt_query/adapters/__init__.py
@@ -0,0 +1,4 @@
+from .postgres_adapter import map_postgres_to_canonical
+from .mongo_adapter import map_mongo_to_canonical
+
+__all__ = ["map_postgres_to_canonical", "map_mongo_to_canonical"]
diff --git a/catopt_query/adapters/mongo_adapter.py b/catopt_query/adapters/mongo_adapter.py
new file mode 100644
index 0000000..dd6fffe
--- /dev/null
+++ b/catopt_query/adapters/mongo_adapter.py
@@ -0,0 +1,12 @@
+from __future__ import annotations
+
+from typing import Dict, Any
+
+from ..core import CanonicalPlan
+from ..protocol import LocalProblem
+from ..core import map_local_to_canonical
+
+
+def map_mongo_to_canonical(local: LocalProblem) -> CanonicalPlan:
+    # Lightweight adapter: MongoDB-like LocalProblem to CanonicalPlan
+    return map_local_to_canonical(local)
diff --git a/catopt_query/adapters/postgres_adapter.py b/catopt_query/adapters/postgres_adapter.py
new file mode 100644
index 0000000..72e3940
--- /dev/null
+++ b/catopt_query/adapters/postgres_adapter.py
@@ -0,0 +1,13 @@
+from __future__ import annotations
+
+from typing import Dict, Any
+
+from ..core import CanonicalPlan
+from ..protocol import LocalProblem
+from ..core import map_local_to_canonical
+
+
+def map_postgres_to_canonical(local: LocalProblem) -> CanonicalPlan:
+    # Very lightweight adapter: map a PostgreSQL-style LocalProblem into a CanonicalPlan
+    # In a full implementation, this would translate Postgres-specific plan elements.
+    return map_local_to_canonical(local)
diff --git a/catopt_query/core.py b/catopt_query/core.py
new file mode 100644
index 0000000..c867399
--- /dev/null
+++ b/catopt_query/core.py
@@ -0,0 +1,48 @@
+from __future__ import annotations
+
+from dataclasses import dataclass, field, asdict
+from typing import List, Dict, Any
+import uuid
+import time
+
+from .protocol import LocalProblem, PlanDelta, SharedVariables, DualVariables
+
+
+@dataclass
+class CanonicalPlan:
+    plan_id: str
+    operations: List[Dict[str, Any]] = field(default_factory=list)
+    total_cost: float = 0.0
+    details: Dict[str, Any] = field(default_factory=dict)
+
+    def to_dict(self) -> Dict[str, Any]:
+        return asdict(self)
+
+
+def map_local_to_canonical(local: LocalProblem) -> CanonicalPlan:
+    # Minimal translation: convert local plan into a single operation with its cost summary
+    op = {
+        "shard": local.shard_id,
+        "predicates": local.predicates,
+        "attributes": local.projected_attributes,
+        "costs": local.costs,
+        "constraints": local.constraints,
+    }
+    total = sum(local.costs.values()) if local.costs else 0.0
+    return CanonicalPlan(plan_id=str(uuid.uuid4()), operations=[op], total_cost=total, details={"shard_alias": local.shard_id})
+
+
+def aggregate_joint_plan(local_plans: List[CanonicalPlan]) -> CanonicalPlan:
+    # Naive aggregation: concatenates operations and sums costs
+    all_ops: List[Dict[str, Any]] = []
+    total = 0.0
+    for p in local_plans:
+        all_ops.extend(p.operations)
+        total += p.total_cost
+    return CanonicalPlan(plan_id=str(uuid.uuid4()), operations=all_ops, total_cost=total, details={"source_count": len(local_plans)})
+
+
+def aggregate_joint_plan_from_locals(locals: List[LocalProblem]) -> CanonicalPlan:
+    cans = [map_local_to_canonical(l) for l in locals]
+    return aggregate_joint_plan(cans)
+
diff --git a/catopt_query/protocol.py b/catopt_query/protocol.py
new file mode 100644
index 0000000..2b0c9cc
--- /dev/null
+++ b/catopt_query/protocol.py
@@ -0,0 +1,46 @@
+from __future__ import annotations
+
+from dataclasses import dataclass, field, asdict
+from typing import Dict, List, Any
+
+
+@dataclass
+class LocalProblem:
+    shard_id: str
+    projected_attributes: List[str]
+    predicates: List[str]
+    costs: Dict[str, float]
+    constraints: Dict[str, Any] = field(default_factory=dict)
+
+    def to_dict(self) -> Dict[str, Any]:
+        return asdict(self)
+
+
+@dataclass
+class SharedVariables:
+    version: int
+    payload: Dict[str, Any] = field(default_factory=dict)
+
+
+@dataclass
+class DualVariables:
+    version: int
+    payload: Dict[str, Any] = field(default_factory=dict)
+
+
+@dataclass
+class PlanDelta:
+    delta_id: str
+    timestamp: float
+    changes: Dict[str, Any] = field(default_factory=dict)
+
+
+@dataclass
+class DataContract:
+    schemas: Dict[str, Any] = field(default_factory=dict)
+    encryption_rules: Dict[str, Any] = field(default_factory=dict)
+
+
+@dataclass
+class AuditLog:
+    entries: List[str] = field(default_factory=list)
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..7fae65c
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,16 @@
+[build-system]
+requires = ["setuptools>=61.0", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "catopt_query"
+version = "0.1.0"
+description = "MVP: Category-Theoretic Compositional Optimizer for Distributed Query Planning"
+readme = "README.md"
+requires-python = ">=3.9"
+license = { text = "MIT" }
+authors = [ { name = "OpenCode" } ]
+dependencies = []
+
+[tool.setuptools.packages.find]
+where = ["."]
diff --git a/test.sh b/test.sh
new file mode 100644
index 0000000..a1bd2a1
--- /dev/null
+++ b/test.sh
@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Ensure the repository root is on PYTHONPATH so tests can import the local package
+# even when the package isn't installed yet in the environment.
+export PYTHONPATH=$(pwd)${PYTHONPATH:+":$PYTHONPATH"}
+
+echo "Running tests..."
+pytest -q
+
+echo "Running packaging build..."
+python3 -m build
+
+echo "All tests and build succeeded."
diff --git a/tests/test_adapters.py b/tests/test_adapters.py
new file mode 100644
index 0000000..3e18ea4
--- /dev/null
+++ b/tests/test_adapters.py
@@ -0,0 +1,28 @@
+from catopt_query.adapters.postgres_adapter import map_postgres_to_canonical
+from catopt_query.adapters.mongo_adapter import map_mongo_to_canonical
+from catopt_query.protocol import LocalProblem
+from catopt_query.core import CanonicalPlan
+
+
+def test_postgres_adapter_maps_to_canonical():
+    lp = LocalProblem(
+        shard_id="pg-1",
+        projected_attributes=["a"],
+        predicates=["a > 1"],
+        costs={"cpu": 1.0},
+    )
+    can = map_postgres_to_canonical(lp)
+    assert isinstance(can, CanonicalPlan)
+    assert can.total_cost == 1.0
+
+
+def test_mongo_adapter_maps_to_canonical():
+    lp = LocalProblem(
+        shard_id="mongo-1",
+        projected_attributes=["b"],
+        predicates=["b != NULL"],
+        costs={"io": 0.2},
+    )
+    can = map_mongo_to_canonical(lp)
+    assert isinstance(can, CanonicalPlan)
+    assert can.total_cost == 0.2
diff --git a/tests/test_protocol.py b/tests/test_protocol.py
new file mode 100644
index 0000000..a2a2055
--- /dev/null
+++ b/tests/test_protocol.py
@@ -0,0 +1,31 @@
+import math
+from catopt_query.protocol import LocalProblem, SharedVariables, DualVariables, PlanDelta, DataContract, AuditLog
+from catopt_query.core import map_local_to_canonical, aggregate_joint_plan
+from catopt_query.core import CanonicalPlan
+
+
+def test_local_problem_serialization():
+    lp = LocalProblem(
+        shard_id="shard-1",
+        projected_attributes=["a", "b"],
+        predicates=["a > 0", "b < 100"],
+        costs={"cpu": 1.2, "io": 0.5},
+        constraints={"timezone": "UTC"},
+    )
+    d = lp.to_dict()
+    assert d["shard_id"] == "shard-1"
+    assert d["predicates"] == ["a > 0", "b < 100"]
+
+
+def test_local_to_canonical_mapping():
+    lp = LocalProblem(
+        shard_id="s1",
+        projected_attributes=["x"],
+        predicates=["x IS NOT NULL"],
+        costs={"cpu": 2.0},
+    )
+    can = map_local_to_canonical(lp)
+    assert isinstance(can, CanonicalPlan)
+    assert can.total_cost == 2.0
+    assert len(can.operations) == 1
+