get_class_hierarchy

Walks extends and implements edges in both directions. With a symbolId, returns the ancestor and descendant chains for that class or interface. Without one, returns every hierarchy tree in the project rooted at its base classes.

When to use

Any time an interface change could ripple to many implementers, or you need to understand an OOP inheritance chain before overriding a method. This is a specialized (cheaper) counterpart to find_importers for structural inheritance only.

Parameters

Name	Type	Required	Description
symbolId	string	no	Root the query at this class/interface. Omit for project-wide trees.
direction	"ancestors" | "descendants" | "both"	no	Which way to walk. Default "both"

Examples

Rooted query -- who implements this interface?

{
  "symbolId": "packages/cli/src/ports/i-storage-port.ts::IStoragePort::interface",
  "direction": "descendants"
}

Full project inheritance forest:

{}

Response (rooted)

{
  "symbolId": "packages/cli/src/ports/i-storage-port.ts::IStoragePort::interface",
  "ancestors": [],
  "descendants": [
    {
      "symbolId": "packages/cli/src/adapters/storage/sqlite.ts::SqliteStorageAdapter::class",
      "name": "SqliteStorageAdapter",
      "kind": "class",
      "file": "packages/cli/src/adapters/storage/sqlite.ts",
      "edgeKind": "implements",
      "depth": 1
    }
  ],
  "_meta": { "totalItems": 1, "returnedItems": 1, "truncated": false }
}

Response (full project)

{
  "hierarchies": [
    {
      "symbolId": "packages/cli/src/ports/i-storage-port.ts::IStoragePort::interface",
      "name": "IStoragePort",
      "kind": "interface",
      "file": "packages/cli/src/ports/i-storage-port.ts",
      "children": [
        {
          "symbolId": "packages/cli/src/adapters/storage/sqlite.ts::SqliteStorageAdapter::class",
          "name": "SqliteStorageAdapter",
          "kind": "class",
          "file": "packages/cli/src/adapters/storage/sqlite.ts",
          "edgeKind": "implements",
          "children": []
        }
      ]
    }
  ],
  "totalClasses": 14,
  "totalEdges": 13,
  "_meta": { "totalItems": 5, "returnedItems": 5, "truncated": false }
}

When to use

• Changing an interface -- list every implementer before you edit the contract.
• Understanding an abstract class -- walk descendants to see concrete subclasses.
• Architecture review -- full-project mode visualises every inheritance tree; pair with get_architectural_overlay for layer context.

Notes

Edge kinds

Only extends and implements edges are followed. For imports/calls/uses reverse walks, use find_importers.

• Roots in full-project mode are nodes that are the target of an extends/implements edge but never the source -- i.e., true base classes or interfaces. If cycles exist, all involved nodes become candidate roots.
• Requires ctxo index.