handle supporting both custom prompts (#6108)

* handle supporting both custom prompts

* handle translations

* handle deprecation warnings better

lib/crewai/src/crewai/agents/agent_builder/base_agent.py

@@ -46,6 +46,7 @@ from crewai.state.checkpoint_config import CheckpointConfig, _coerce_checkpoint
 from crewai.tools.base_tool import BaseTool, Tool
 from crewai.types.callback import SerializableCallable
 from crewai.utilities.config import process_config
+from crewai.utilities.i18n import I18N, get_i18n
 from crewai.utilities.logger import Logger
 from crewai.utilities.rpm_controller import RPMController
 from crewai.utilities.string_utils import interpolate_only
@@ -186,6 +187,7 @@ class BaseAgent(BaseModel, ABC, metaclass=AgentMeta):
         tools (list[Any] | None): Tools at the agent's disposal.
         max_iter (int): Maximum iterations for an agent to execute a task.
         agent_executor: An instance of the CrewAgentExecutor class.
+        i18n (I18N): Internationalization settings.
         llm (Any): Language model that will run the agent.
         crew (Any): Crew to which the agent belongs.
 
@@ -265,6 +267,14 @@ class BaseAgent(BaseModel, ABC, metaclass=AgentMeta):
             _serialize_executor_ref, return_type=dict | None, when_used="json"
         ),
     ] = Field(default=None, description="An instance of the CrewAgentExecutor class.")
+    i18n: I18N = Field(
+        default_factory=get_i18n,
+        description="Internationalization settings.",
+        deprecated=(
+            "Agent.i18n is deprecated and will be removed in a future release. "
+            "Use crewai.utilities.i18n.get_i18n() or Crew(prompt_file=...) instead."
+        ),
+    )
 
     llm: Annotated[
         str | BaseLLM | None,

lib/crewai/tests/agents/test_agent.py

@@ -4,6 +4,7 @@ import os
 import threading
 from unittest import mock
 from unittest.mock import MagicMock, patch
+import warnings
 
 from crewai.agents.crew_agent_executor import AgentFinish, CrewAgentExecutor
 from crewai.constants import DEFAULT_LLM_MODEL
@@ -77,6 +78,51 @@ def test_agent_creation():
     assert agent.backstory == "test backstory"
 
 
+def test_agent_exposes_i18n_for_backward_compatibility():
+    from crewai.utilities.i18n import I18N_DEFAULT
+
+    agent = Agent(role="test role", goal="test goal", backstory="test backstory")
+
+    with pytest.warns(DeprecationWarning, match="Agent.i18n is deprecated"):
+        i18n = agent.i18n
+
+    assert i18n is I18N_DEFAULT
+    assert isinstance(i18n.slice("role_playing"), str)
+
+
+def test_agent_accepts_custom_i18n():
+    from crewai.utilities.i18n import I18N
+
+    prompt_file = os.path.join(
+        os.path.dirname(__file__), "..", "utilities", "prompts.json"
+    )
+    i18n = I18N(prompt_file=prompt_file)
+    agent = Agent(
+        role="test role",
+        goal="test goal",
+        backstory="test backstory",
+        i18n=i18n,
+    )
+
+    with pytest.warns(DeprecationWarning, match="Agent.i18n is deprecated"):
+        agent_i18n = agent.i18n
+
+    assert agent_i18n is i18n
+    assert agent_i18n.slice("role_playing") == "Lorem ipsum dolor sit amet"
+
+
+def test_agent_copy_does_not_emit_i18n_deprecation_warning():
+    agent = Agent(role="test role", goal="test goal", backstory="test backstory")
+
+    with warnings.catch_warnings(record=True) as caught_warnings:
+        warnings.simplefilter("always", DeprecationWarning)
+        agent.copy()
+
+    assert not any(
+        "Agent.i18n is deprecated" in str(w.message) for w in caught_warnings
+    )
+
+
 def test_agent_with_only_system_template():
     """Test that an agent with only system_template works without errors."""
     agent = Agent(