diff --git a/apps/coordinator-api/src/app/contexts/knowledge/routers/__init__.py b/apps/coordinator-api/src/app/contexts/knowledge/routers/__init__.py
new file mode 100644
index 00000000..a28ee69a
--- /dev/null
+++ b/apps/coordinator-api/src/app/contexts/knowledge/routers/__init__.py
@@ -0,0 +1,3 @@
+from .knowledge import router
+
+__all__ = ["router"]
diff --git a/apps/coordinator-api/src/app/contexts/knowledge/routers/knowledge.py b/apps/coordinator-api/src/app/contexts/knowledge/routers/knowledge.py
new file mode 100644
index 00000000..ac874ccd
--- /dev/null
+++ b/apps/coordinator-api/src/app/contexts/knowledge/routers/knowledge.py
@@ -0,0 +1,177 @@
+from typing import Any, Dict, List, Optional
+
+from fastapi import APIRouter, Depends, HTTPException, Query, Request
+from pydantic import BaseModel, Field
+from sqlalchemy.orm import Session
+
+from aitbc import get_logger
+from aitbc.rate_limiting import rate_limit
+from ....storage import get_session
+
+router = APIRouter(prefix="/knowledge", tags=["knowledge"])
+
+logger = get_logger(__name__)
+
+
+# Pydantic models for API requests/responses
+class KnowledgeGraphCreateRequest(BaseModel):
+    """Request model for creating a knowledge graph"""
+    name: str = Field(..., min_length=1, max_length=100)
+    description: str = Field(..., min_length=1, max_length=500)
+    schema: str = Field(default=None)
+
+
+class KnowledgeGraphResponse(BaseModel):
+    """Response model for knowledge graph"""
+    id: str
+    name: str
+    description: str
+    schema: Optional[str]
+    owner: str
+    created_at: str
+    node_count: int
+    edge_count: int
+
+
+class KnowledgeNodeRequest(BaseModel):
+    """Request model for contributing knowledge"""
+    graph_id: str = Field(..., min_length=1)
+    node_type: str = Field(..., min_length=1)
+    data: Dict[str, Any] = Field(default_factory=dict)
+    relationships: List[Dict[str, Any]] = Field(default_factory=list)
+
+
+class KnowledgeNodeResponse(BaseModel):
+    """Response model for knowledge node"""
+    id: str
+    graph_id: str
+    node_type: str
+    data: Dict[str, Any]
+    relationships: List[Dict[str, Any]]
+    created_at: str
+
+
+# API endpoints
+@router.post("/graphs", response_model=KnowledgeGraphResponse)
+@rate_limit(rate=20, per=60)
+async def create_knowledge_graph(
+    request: Request,
+    graph_request: KnowledgeGraphCreateRequest,
+    session: Session = Depends(get_session)
+) -> KnowledgeGraphResponse:
+    """Create a new knowledge graph"""
+    try:
+        # Simplified implementation - return mock response
+        graph_id = f"kg-{hash(graph_request.name)}"
+        return KnowledgeGraphResponse(
+            id=graph_id,
+            name=graph_request.name,
+            description=graph_request.description,
+            schema=graph_request.schema,
+            owner="test_user",
+            created_at="2026-05-19T00:00:00Z",
+            node_count=0,
+            edge_count=0
+        )
+    except Exception as e:
+        logger.error(f"Failed to create knowledge graph: {e}")
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.get("/graphs", response_model=List[KnowledgeGraphResponse])
+@rate_limit(rate=200, per=60)
+async def list_knowledge_graphs(
+    request: Request,
+    session: Session = Depends(get_session)
+) -> List[KnowledgeGraphResponse]:
+    """List all available knowledge graphs"""
+    try:
+        # Simplified implementation - return empty list
+        return []
+    except Exception as e:
+        logger.error(f"Failed to list knowledge graphs: {e}")
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.get("/graphs/{graph_id}", response_model=KnowledgeGraphResponse)
+@rate_limit(rate=200, per=60)
+async def get_knowledge_graph(
+    request: Request,
+    graph_id: str,
+    session: Session = Depends(get_session)
+) -> KnowledgeGraphResponse:
+    """Get details of a specific knowledge graph"""
+    try:
+        # Simplified implementation - return mock response
+        return KnowledgeGraphResponse(
+            id=graph_id,
+            name="Test Graph",
+            description="Test knowledge graph",
+            schema=None,
+            owner="test_user",
+            created_at="2026-05-19T00:00:00Z",
+            node_count=0,
+            edge_count=0
+        )
+    except Exception as e:
+        logger.error(f"Failed to get knowledge graph {graph_id}: {e}")
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.post("/graphs/{graph_id}/nodes", response_model=KnowledgeNodeResponse)
+@rate_limit(rate=20, per=60)
+async def contribute_knowledge(
+    request: Request,
+    graph_id: str,
+    node_request: KnowledgeNodeRequest,
+    session: Session = Depends(get_session)
+) -> KnowledgeNodeResponse:
+    """Contribute knowledge to a graph"""
+    try:
+        # Simplified implementation - return mock response
+        node_id = f"node-{hash(node_request.node_type)}"
+        return KnowledgeNodeResponse(
+            id=node_id,
+            graph_id=graph_id,
+            node_type=node_request.node_type,
+            data=node_request.data,
+            relationships=node_request.relationships,
+            created_at="2026-05-19T00:00:00Z"
+        )
+    except Exception as e:
+        logger.error(f"Failed to contribute knowledge to graph {graph_id}: {e}")
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.get("/graphs/{graph_id}/query", response_model=List[KnowledgeNodeResponse])
+@rate_limit(rate=200, per=60)
+async def query_knowledge_graph(
+    request: Request,
+    graph_id: str,
+    node_type: Optional[str] = Query(default=None),
+    filters: Optional[str] = Query(default=None),
+    session: Session = Depends(get_session)
+) -> List[KnowledgeNodeResponse]:
+    """Query knowledge from a graph"""
+    try:
+        # Simplified implementation - return empty list
+        return []
+    except Exception as e:
+        logger.error(f"Failed to query knowledge graph {graph_id}: {e}")
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.post("/graphs/{graph_id}/join")
+@rate_limit(rate=20, per=60)
+async def join_knowledge_graph(
+    request: Request,
+    graph_id: str,
+    session: Session = Depends(get_session)
+) -> Dict[str, str]:
+    """Join an existing knowledge graph"""
+    try:
+        # Simplified implementation - return success
+        return {"status": "success", "message": f"Joined graph {graph_id}"}
+    except Exception as e:
+        logger.error(f"Failed to join knowledge graph {graph_id}: {e}")
+        raise HTTPException(status_code=500, detail=str(e))
diff --git a/apps/coordinator-api/src/app/main.py b/apps/coordinator-api/src/app/main.py
index 8fc0e0ae..db03d422 100755
--- a/apps/coordinator-api/src/app/main.py
+++ b/apps/coordinator-api/src/app/main.py
@@ -540,6 +540,14 @@ def create_app() -> FastAPI:
     except Exception as e:
         logger.warning(f"Failed to include rewards router: {e}")
 
+    # Include Knowledge Graph router
+    try:
+        from .contexts.knowledge.routers.knowledge import router as knowledge_router
+        app.include_router(knowledge_router, prefix="/v1")
+        logger.info("Knowledge Graph router included")
+    except Exception as e:
+        logger.warning(f"Failed to include Knowledge Graph router: {e}")
+
     # Include marketplace_offers AFTER global_marketplace to override the /offers endpoint
     app.include_router(marketplace_offers, prefix="/v1")