diff --git a/.claude/docs/architectural_patterns.md b/.claude/docs/architectural_patterns.md
index 4a5c9c494..4bf214b2e 100644
--- a/.claude/docs/architectural_patterns.md
+++ b/.claude/docs/architectural_patterns.md
@@ -85,7 +85,7 @@ Request → Middleware → APIRouter → Endpoint function → Service layer →
 
 ### Endpoint modules: single file or package
 
-A module under `sparkth/api/v1/` takes one of two shapes. `sparkth/api/v1/api.py` mounts
+A module under `sparkth/api/v1/` takes one of two shapes. `sparkth/api/v1/__init__.py` mounts
 each one the same way — `include_router(<module>.router, prefix=...)` — so the shape is
 an internal organisation choice and changing it never moves a URL.
 
@@ -103,9 +103,9 @@ sparkth/api/v1/<name>/
     schemas.py    # request/response models owned by this module
 ```
 
-- `__init__.py` re-exports `router` and carries `__all__ = ["router"]`. This is a
-  deliberate exception to the "avoid re-exports" rule: it keeps `api.py`'s mounting
-  uniform across both shapes.
+- The endpoint package's own `__init__.py` re-exports `router` and carries
+  `__all__ = ["router"]`. This is a deliberate exception to the "avoid re-exports" rule:
+  it keeps the mounting in `sparkth/api/v1/__init__.py` uniform across both shapes.
 - It is also where `register_exception_handler(ExcClass, status_code)` calls live, so a
   domain's exception → status mapping sits beside the routes that raise it (see section
   8, and `permissions/__init__.py` / `whitelist/__init__.py`). A package with no domain
@@ -118,9 +118,9 @@ sparkth/api/v1/<name>/
   into a package makes every other domain import that package, and importing any module
   from it executes its `__init__.py` and therefore its `routes.py`, which turns a later
   import in the other direction into a circular one.
-- Route paths come from the prefix in `api.py`, never from the package name, so
-  converting a file to a package is a pure refactor: the OpenAPI document, the generated
-  frontend client, and every URL stay byte-identical.
+- Route paths come from the prefix in `sparkth/api/v1/__init__.py`, never from the package
+  name, so converting a file to a package is a pure refactor: the OpenAPI document, the
+  generated frontend client, and every URL stay byte-identical.
 
 ---
 
diff --git a/sparkth/api/v1/__init__.py b/sparkth/api/v1/__init__.py
index e69de29bb..e570a92c6 100644
--- a/sparkth/api/v1/__init__.py
+++ b/sparkth/api/v1/__init__.py
@@ -0,0 +1,28 @@
+"""Version 1 of the REST API.
+
+Assembles ``api_router`` from every endpoint module in this package. Each module
+exposes a ``router`` — whether it is a single file (``auth.py``) or a package with
+its own ``routes.py`` and ``schemas.py`` (``user/``) — and is mounted here under
+its URL prefix and OpenAPI tag. ``sparkth.main.assemble_app`` mounts the result at
+``/api/v1``, so every path in this file is relative to that.
+
+Prefixes are the public URL contract: changing one here moves an endpoint for every
+client, independently of how the module behind it is laid out on disk.
+"""
+
+from fastapi import APIRouter
+
+from sparkth.api.v1 import analytics, auth, file_parser, language, llm, permissions, user, user_plugins, whitelist
+
+api_router = APIRouter()
+api_router.include_router(auth.router, prefix="/auth", tags=["auth"])
+api_router.include_router(user.router, prefix="/user", tags=["user"])
+api_router.include_router(language.router, prefix="/languages", tags=["Languages"])
+api_router.include_router(user_plugins.router, prefix="/user-plugins", tags=["User Plugins"])
+api_router.include_router(file_parser.router, prefix="/parser", tags=["File Parser"])
+api_router.include_router(whitelist.router, prefix="/whitelist", tags=["Whitelist"])
+api_router.include_router(llm.router, prefix="/llm", tags=["LLM Configuration"])
+api_router.include_router(permissions.router, prefix="/permissions", tags=["Permissions"])
+api_router.include_router(analytics.router, prefix="/analytics", tags=["Analytics"])
+
+__all__ = ["api_router"]
diff --git a/sparkth/api/v1/api.py b/sparkth/api/v1/api.py
deleted file mode 100644
index 2f701e894..000000000
--- a/sparkth/api/v1/api.py
+++ /dev/null
@@ -1,14 +0,0 @@
-from fastapi import APIRouter
-
-from sparkth.api.v1 import analytics, auth, file_parser, language, llm, permissions, user, user_plugins, whitelist
-
-api_router = APIRouter()
-api_router.include_router(auth.router, prefix="/auth", tags=["auth"])
-api_router.include_router(user.router, prefix="/user", tags=["user"])
-api_router.include_router(language.router, prefix="/languages", tags=["Languages"])
-api_router.include_router(user_plugins.router, prefix="/user-plugins", tags=["User Plugins"])
-api_router.include_router(file_parser.router, prefix="/parser", tags=["File Parser"])
-api_router.include_router(whitelist.router, prefix="/whitelist", tags=["Whitelist"])
-api_router.include_router(llm.router, prefix="/llm", tags=["LLM Configuration"])
-api_router.include_router(permissions.router, prefix="/permissions", tags=["Permissions"])
-api_router.include_router(analytics.router, prefix="/analytics", tags=["Analytics"])
diff --git a/sparkth/main.py b/sparkth/main.py
index 01b98cf78..f8db47cf7 100644
--- a/sparkth/main.py
+++ b/sparkth/main.py
@@ -8,7 +8,7 @@
 from starlette.types import Lifespan
 
 import sparkth.lib.audit.callbacks  # noqa: F401  # registers the process-global LangChain audit callback on import
-from sparkth.api.v1.api import api_router
+from sparkth.api.v1 import api_router
 from sparkth.core.audit.middleware import AuditContextMiddleware
 from sparkth.core.config import MCP_MOUNT_PATH, get_settings
 from sparkth.core.exceptions.handlers import EXCEPTION_HANDLERS