Add backend to ragas main (#2174)

Hello!

Kicking off API migration first with this PR, it primarily:

1. Moves the backend to ragas main
2. Rename imports
3. Moves tests from experimental to ragas main

This is a cascading PR i.e. you are expected to review and merge
#2173 before reviewing
this

Author: NirantK

CLAUDE.md

@@ -162,7 +162,7 @@ The experimental features are now integrated into the main ragas package:
 To use experimental features:
 ```python
 from ragas.experimental import Dataset, experiment
-from ragas.experimental.backends import get_registry
+from ragas.backends import get_registry
 ```
 
 ## Debugging Logs

ragas/pyproject.toml

@@ -57,10 +57,10 @@ ai-frameworks = ["haystack-ai"]
 
 test = []
 [project.entry-points."ragas.backends"]
-"local/csv" = "ragas.experimental.backends.local_csv:LocalCSVBackend"
-"local/jsonl" = "ragas.experimental.backends.local_jsonl:LocalJSONLBackend"
-"inmemory" = "ragas.experimental.backends.inmemory:InMemoryBackend"
-"gdrive" = "ragas.experimental.backends.gdrive_backend:GDriveBackend"
+"local/csv" = "ragas.backends.local_csv:LocalCSVBackend"
+"local/jsonl" = "ragas.backends.local_jsonl:LocalJSONLBackend"
+"inmemory" = "ragas.backends.inmemory:InMemoryBackend"
+"gdrive" = "ragas.backends.gdrive_backend:GDriveBackend"
 
 [project.scripts]
 ragas-experimental = "ragas.experimental.cli:app"

ragas/src/ragas/__init__.py

@@ -3,6 +3,9 @@
 from ragas.evaluation import evaluate
 from ragas.run_config import RunConfig
 
+# Backend imports
+from ragas import backends
+
 try:
     from ._version import version as __version__
 except ImportError:
@@ -19,6 +22,7 @@
     "cacher",
     "CacheInterface",
     "DiskCacheBackend",
+    "backends",
 ]
 
 

…rc/ragas/experimental/backends/README.md ragas/src/ragas/backends/README.mdragas/src/ragas/experimental/backends/README.md renamed to ragas/src/ragas/backends/README.md ragas/src/ragas/experimental/backends/README.md renamed to ragas/src/ragas/backends/README.md

@@ -17,7 +17,7 @@ Registry (dict-like) → Backend (implements BaseBackend) → Storage
 
 **1. Implement BaseBackend:**
 ```python
-from ragas.experimental.backends.base import BaseBackend
+from ragas.backends.base import BaseBackend
 
 class MyBackend(BaseBackend):
     def __init__(self, connection_string: str):
@@ -43,7 +43,7 @@ class MyBackend(BaseBackend):
 
 **3. Use:**
 ```python
-from ragas.experimental.backends import get_registry
+from ragas.backends import get_registry
 registry = get_registry()
 backend = registry["my_backend"](connection_string="...")
 ```
@@ -69,7 +69,7 @@ def list_experiments() -> List[str]
 
 **Dict-like interface:**
 ```python
-from ragas.experimental.backends import get_registry
+from ragas.backends import get_registry
 
 registry = get_registry()
 print(registry)  # {'local/csv': <class 'LocalCSVBackend'>, ...}
@@ -182,7 +182,7 @@ my-backend-plugin/
 **Install & use:**
 ```bash
 pip install my-backend-plugin
-python -c "from ragas.experimental.backends import get_registry; print(get_registry())"
+python -c "from ragas.backends import get_registry; print(get_registry())"
 ```
 
 ## Registry Internals
@@ -195,7 +195,7 @@ python -c "from ragas.experimental.backends import get_registry; print(get_regis
 
 **Debugging:**
 ```python
-from ragas.experimental.backends import get_registry
+from ragas.backends import get_registry
 registry = get_registry()
 
 # Check what's available