diff --git a/MODULE_SPEC.yaml b/MODULE_SPEC.yaml
new file mode 100644
index 0000000..7d85c2a
--- /dev/null
+++ b/MODULE_SPEC.yaml
@@ -0,0 +1,41 @@
+{
+  "schema_version": 1,
+  "module_id": "quant_engine",
+  "authority": {"scope": "module_metadata", "subject": "quant_engine", "owner": "quant-engine-owner", "source": "MODULE_SPEC.yaml", "revision": 1, "effective_from": "2026-08-20T00:00:00+08:00"},
+  "repository": {"name": "quant_engine", "workspace_id": "researchhub", "type": "research_engine", "maturity": "operational"},
+  "bounded_context": {
+    "domain": "quantitative-research-engine",
+    "responsibility": "Own reusable quantitative research calculations for factors, indicators, execution simulation, backtesting, portfolio decomposition, risk, and performance metrics.",
+    "prohibited_responsibilities": [
+      "Presenting research calculations, simulations, backtests, or metrics as investment advice or guaranteed performance",
+      "Submitting live orders, routing trades, managing brokerage accounts, or claiming transaction execution",
+      "Owning market-data source facts, research-result publication, or platform presentation state",
+      "Loading provider credentials, brokerage credentials, or production secrets",
+      "Changing financial model semantics through module metadata"
+    ]
+  },
+  "capabilities": [
+    {"id": "factor-and-indicator-calculation", "summary": "Calculate reusable alpha factors and technical indicators from caller-supplied data.", "status": "operational"},
+    {"id": "execution-simulation", "summary": "Simulate costs, slippage, market constraints, fills, NAV, and PnL without live order routing.", "status": "operational"},
+    {"id": "portfolio-backtesting", "summary": "Run weight-based backtests and benchmark comparisons.", "status": "operational"},
+    {"id": "risk-and-performance-analysis", "summary": "Calculate portfolio decomposition, risk contribution, and performance statistics.", "status": "operational"}
+  ],
+  "data": {"owns": [
+    {"asset_id": "quantitative-model-implementations", "kind": "model", "classification": "internal"},
+    {"asset_id": "simulation-and-metric-results", "kind": "artifact", "classification": "confidential"}
+  ]},
+  "contracts": {"provides": [], "consumes": []},
+  "dependencies": [],
+  "agent_context": {
+    "default_entrypoints": [
+      {"path": "README.md", "purpose": "Current engine scope, modules, dependencies, and non-live usage examples."},
+      {"path": "pyproject.toml", "purpose": "Supported Python version, package version, dependencies, and quality configuration."}
+    ],
+    "excluded_paths": ["graphify-out", ".venv", "build", "dist"],
+    "max_default_tokens": 8000
+  },
+  "verification": {"commands": [
+    {"id": "module-metadata", "argv": ["python3", "tests/governance/test_module_spec.py"], "cwd": ".", "network": false, "required": true},
+    {"id": "unit-tests", "argv": ["python3", "-m", "pytest"], "cwd": ".", "network": false, "required": true}
+  ]}
+}