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..bea67b8
--- /dev/null
+++ b/AGENTS.md
@@ -0,0 +1,31 @@
+Architecture and Contribution Guide for AI Agents
+
+Purpose
+This repository contains Phase0 primitives for SoundGraph Studio: content-addressed audio modules, patch graphs with Merkle roots, and provenance events. It's intentionally small and well-tested so subsequent agents can expand to delta-sync, DAW adapters, and a governance ledger.
+
+Tech stack
+- Language: Python 3.8+
+- Crypto: cryptography (ed25519 signatures)
+- Testing: pytest
+- Packaging: setuptools/pyproject.toml
+
+Repository layout
+- pyproject.toml - build metadata and dependencies
+- setup.cfg - setuptools configuration
+- README.md - user-facing documentation
+- AGENTS.md - this file
+- test.sh - run tests and build
+- idea44_soundgraph_studio_verifiable/ - Python package code
+- tests/ - pytest tests
+
+Agent rules
+1. Always run the test suite after changes: `./test.sh`.
+2. Avoid making broad refactors unless requested; prefer small, well-scoped patches.
+3. When adding dependencies, update pyproject.toml and setup.cfg accordingly.
+4. Do NOT create `READY_TO_PUBLISH` unless the repository fully implements the original idea and all tests pass (the orchestrator enforces this).
+5. If you need to run commands, use the provided tooling and keep changes minimal.
+
+Development notes
+- The package name must remain `idea44_soundgraph_studio_verifiable`.
+- Packaging must build successfully with `python3 -m build`.
+- Tests must be present and passing; any added functionality should include at least one test.
diff --git a/README.md b/README.md
index 7002e7f..5dbbf95 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,24 @@
-# idea44-soundgraph-studio-verifiable
+# SoundGraph Studio — Phase0 primitives
 
-Source logic for Idea #44
\ No newline at end of file
+This repository contains Phase0 primitives for SoundGraph Studio: a content-addressed representation of AudioModule objects, an AudioPatch structure with a Merkle-based root for provable inclusion, and simple provenance events with cryptographic signatures.
+
+What is included
+- A small Python package `idea44_soundgraph_studio_verifiable` implementing:
+  - AudioModule: content-addressed modules (SHA-256 over canonical JSON)
+  - AudioPatch: nodes referencing module CIDs and edges; Merkle root over nodes+edges
+  - ProvenanceEvent: lightweight signed events (ed25519) for tamper-evident audit trails
+- Tests (pytest) that validate CID reproducibility, Merkle inclusion proofs, and signature verification
+- Packaging (pyproject.toml + setup.cfg) and a `test.sh` that runs the test suite and verifies build
+
+How to run tests
+1. Make sure you have Python 3.8+ and `python3 -m pip` available.
+2. Run:
+
+```bash
+./test.sh
+```
+
+This will install the package in editable mode, run pytest, and run `python3 -m build` to verify packaging.
+
+Notes
+- This is intentionally focused on Phase0 local graph primitives — a solid foundation for future delta-sync, adapters, and governance ledger work.
diff --git a/idea44_soundgraph_studio_verifiable/__init__.py b/idea44_soundgraph_studio_verifiable/__init__.py
new file mode 100644
index 0000000..ce0f928
--- /dev/null
+++ b/idea44_soundgraph_studio_verifiable/__init__.py
@@ -0,0 +1,9 @@
+"""idea44_soundgraph_studio_verifiable
+
+Phase0 primitives: content-addressed AudioModule, AudioPatch with Merkle root,
+and ProvenanceEvent signing/verification.
+"""
+
+from .core import AudioModule, AudioPatch, ProvenanceEvent
+
+__all__ = ["AudioModule", "AudioPatch", "ProvenanceEvent"]
diff --git a/idea44_soundgraph_studio_verifiable/core.py b/idea44_soundgraph_studio_verifiable/core.py
new file mode 100644
index 0000000..9efbdbe
--- /dev/null
+++ b/idea44_soundgraph_studio_verifiable/core.py
@@ -0,0 +1,169 @@
+"""Core primitives: AudioModule, AudioPatch, ProvenanceEvent
+
+Small, well-scoped implementations suitable for Phase0 tests.
+"""
+from __future__ import annotations
+
+import json
+import hashlib
+import time
+import uuid
+from dataclasses import dataclass, field, asdict
+from typing import List, Dict, Tuple
+
+from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey, Ed25519PublicKey
+from cryptography.hazmat.primitives import serialization
+
+
+def canonical_json(data) -> bytes:
+    # deterministic JSON encoding
+    return json.dumps(data, separators=(",", ":"), sort_keys=True, ensure_ascii=False).encode("utf-8")
+
+
+def sha256(b: bytes) -> str:
+    return hashlib.sha256(b).hexdigest()
+
+
+@dataclass
+class AudioModule:
+    id: str
+    type: str
+    params: Dict
+    version: str = "0.1"
+    license: str = ""
+
+    def to_dict(self) -> Dict:
+        return asdict(self)
+
+    def cid(self) -> str:
+        """Content ID: SHA-256 over canonical JSON of the module."""
+        data = self.to_dict()
+        return sha256(canonical_json(data))
+
+    @staticmethod
+    def make(type: str, params: Dict, version: str = "0.1", license: str = "") -> "AudioModule":
+        return AudioModule(id=str(uuid.uuid4()), type=type, params=params, version=version, license=license)
+
+
+def merkle_tree_root(leaves: List[bytes]) -> str:
+    """Simple Merkle tree root (binary) over raw leaf bytes. Returns hex digest."""
+    if not leaves:
+        return sha256(b"")
+
+    level = [hashlib.sha256(l).digest() for l in leaves]
+
+    while len(level) > 1:
+        next_level = []
+        for i in range(0, len(level), 2):
+            left = level[i]
+            right = level[i + 1] if i + 1 < len(level) else left
+            next_level.append(hashlib.sha256(left + right).digest())
+        level = next_level
+
+    return level[0].hex()
+
+
+def merkle_proof(leaves: List[bytes], index: int) -> List[Tuple[str, str]]:
+    """Return a list of (sibling_hash(hex), direction) where direction is 'L' or 'R'."""
+    if index < 0 or index >= len(leaves):
+        raise IndexError("leaf index")
+
+    # compute tree levels as bytes
+    levels = [ [hashlib.sha256(l).digest() for l in leaves] ]
+
+    while len(levels[-1]) > 1:
+        cur = levels[-1]
+        nxt = []
+        for i in range(0, len(cur), 2):
+            left = cur[i]
+            right = cur[i+1] if i+1 < len(cur) else left
+            nxt.append(hashlib.sha256(left + right).digest())
+        levels.append(nxt)
+
+    proof = []
+    idx = index
+    for level in levels[:-1]:
+        sibling_idx = idx ^ 1
+        sibling = level[sibling_idx] if sibling_idx < len(level) else level[idx]
+        direction = 'L' if sibling_idx < idx else 'R'
+        proof.append((sibling.hex(), direction))
+        idx = idx // 2
+
+    return proof
+
+
+def verify_merkle_proof(leaf: bytes, proof: List[Tuple[str, str]], root_hex: str) -> bool:
+    cur = hashlib.sha256(leaf).digest()
+    for sibling_hex, direction in proof:
+        sibling = bytes.fromhex(sibling_hex)
+        if direction == 'L':
+            cur = hashlib.sha256(sibling + cur).digest()
+        else:
+            cur = hashlib.sha256(cur + sibling).digest()
+    return cur.hex() == root_hex
+
+
+@dataclass
+class AudioPatch:
+    nodes: List[Dict] = field(default_factory=list)  # each node: {id, module_cid, params}
+    edges: List[Tuple[str, str]] = field(default_factory=list)  # list of (from_node_id, to_node_id)
+    metadata: Dict = field(default_factory=dict)
+
+    def to_dict(self) -> Dict:
+        return {
+            "nodes": self.nodes,
+            "edges": self.edges,
+            "metadata": self.metadata,
+        }
+
+    def merkle_root(self) -> str:
+        # leaves are canonical JSON of each node (sorted by node id) and each edge
+        node_items = sorted(self.nodes, key=lambda n: n.get("id"))
+        node_leaves = [canonical_json(n) for n in node_items]
+        edge_items = sorted([{"from": f, "to": t} for f,t in self.edges], key=lambda e: (e['from'], e['to']))
+        edge_leaves = [canonical_json(e) for e in edge_items]
+        leaves = node_leaves + edge_leaves
+        return merkle_tree_root(leaves)
+
+    def inclusion_proof_for_module_cid(self, module_cid: str) -> Tuple[List[Tuple[str,str]], bytes]:
+        # find the node(s) that reference this module_cid and return proof for first occurrence
+        node_items = sorted(self.nodes, key=lambda n: n.get("id"))
+        node_leaves = [canonical_json(n) for n in node_items]
+        edge_items = sorted([{"from": f, "to": t} for f,t in self.edges], key=lambda e: (e['from'], e['to']))
+        edge_leaves = [canonical_json(e) for e in edge_items]
+        leaves = node_leaves + edge_leaves
+
+        for idx, n in enumerate(node_items):
+            if n.get("module_cid") == module_cid:
+                proof = merkle_proof(leaves, idx)
+                return proof, node_leaves[idx]
+
+        raise KeyError("module_cid not referenced in patch")
+
+
+@dataclass
+class ProvenanceEvent:
+    patch_id: str
+    actor: str
+    timestamp: float
+    op_hash: str
+    signature: bytes = b""
+
+    def to_dict(self) -> Dict:
+        return {"patch_id": self.patch_id, "actor": self.actor, "timestamp": self.timestamp, "op_hash": self.op_hash}
+
+    def sign(self, private_key: Ed25519PrivateKey) -> None:
+        self.signature = private_key.sign(canonical_json(self.to_dict()))
+
+    def verify(self, public_key: Ed25519PublicKey) -> bool:
+        try:
+            public_key.verify(self.signature, canonical_json(self.to_dict()))
+            return True
+        except Exception:
+            return False
+
+
+def generate_ed25519_keypair() -> Tuple[Ed25519PrivateKey, Ed25519PublicKey]:
+    sk = Ed25519PrivateKey.generate()
+    pk = sk.public_key()
+    return sk, pk
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..b1c45d3
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,12 @@
+[build-system]
+requires = ["setuptools>=61.0","wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "idea44_soundgraph_studio_verifiable"
+version = "0.0.1"
+description = "SoundGraph Studio primitives: Merkle-DAG patches, content-addressed modules, and provenance events (MVP Phase0)"
+readme = "README.md"
+authors = [ { name = "OpenCode" } ]
+requires-python = ">=3.8"
+dependencies = ["cryptography>=39.0.0"]
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..a5f9de3
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,13 @@
+[metadata]
+name = idea44_soundgraph_studio_verifiable
+version = 0.0.1
+description = SoundGraph Studio primitives: Merkle-DAG patches, content-addressed modules, and provenance events (MVP Phase0)
+long_description = file: README.md
+long_description_content_type = text/markdown
+author = OpenCode
+
+[options]
+packages = find:
+install_requires =
+    cryptography>=39.0.0
+python_requires = >=3.8
diff --git a/test.sh b/test.sh
new file mode 100644
index 0000000..fa74791
--- /dev/null
+++ b/test.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+echo "Installing package in editable mode..."
+python3 -m pip install -e .
+
+echo "Running tests..."
+pytest -q
+
+echo "Building package..."
+python3 -m build
+
+echo "All done"
diff --git a/tests/test_core.py b/tests/test_core.py
new file mode 100644
index 0000000..144caa7
--- /dev/null
+++ b/tests/test_core.py
@@ -0,0 +1,35 @@
+import json
+from idea44_soundgraph_studio_verifiable.core import AudioModule, AudioPatch, generate_ed25519_keypair, ProvenanceEvent
+
+
+def test_audio_module_cid_is_stable():
+    m = AudioModule.make("oscillator", {"freq": 440, "wave": "sine"}, version="0.1")
+    cid1 = m.cid()
+    # recompute from dict to ensure canonicalization is stable
+    cid2 = AudioModule(id=m.id, type=m.type, params=m.params, version=m.version, license=m.license).cid()
+    assert cid1 == cid2
+
+
+def test_patch_merkle_and_inclusion_proof():
+    m1 = AudioModule.make("oscillator", {"freq": 220})
+    m2 = AudioModule.make("filter", {"type": "lowpass", "cutoff": 1000})
+
+    node1 = {"id": "n1", "module_cid": m1.cid(), "params": {}}
+    node2 = {"id": "n2", "module_cid": m2.cid(), "params": {}}
+
+    patch = AudioPatch(nodes=[node1, node2], edges=[("n1","n2")])
+    root = patch.merkle_root()
+    assert isinstance(root, str) and len(root) == 64
+
+    proof, leaf = patch.inclusion_proof_for_module_cid(m1.cid())
+    # verify proof using the exported verification helper
+    from idea44_soundgraph_studio_verifiable.core import verify_merkle_proof
+
+    assert verify_merkle_proof(leaf, proof, root)
+
+
+def test_provenance_event_sign_and_verify():
+    sk, pk = generate_ed25519_keypair()
+    ev = ProvenanceEvent(patch_id="patch-1", actor="alice", timestamp=123456.0, op_hash="deadbeef")
+    ev.sign(sk)
+    assert ev.verify(pk)