feat: integrate skill discovery and activation into agent execution

lib/crewai/src/crewai/agent/core.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import asyncio
 from collections.abc import Callable, Coroutine, Sequence
+from pathlib import Path
 import shutil
 import subprocess
 import time
@@ -26,6 +27,7 @@ from typing_extensions import Self
 
 from crewai.agent.utils import (
     ahandle_knowledge_retrieval,
+    append_skill_context,
     apply_training_data,
     build_task_prompt_with_schema,
     format_task_with_context,
@@ -74,6 +76,8 @@ from crewai.mcp.transports.stdio import StdioTransport
 from crewai.memory.contextual.contextual_memory import ContextualMemory
 from crewai.rag.embeddings.types import EmbedderConfig
 from crewai.security.fingerprint import Fingerprint
+from crewai.skills.loader import activate_skill, discover_skills
+from crewai.skills.models import Skill as SkillModel
 from crewai.tools.agent_tools.agent_tools import AgentTools
 from crewai.utilities.agent_utils import (
     get_tool_names,
@@ -310,6 +314,36 @@ class Agent(BaseAgent):
         except (TypeError, ValueError) as e:
             raise ValueError(f"Invalid Knowledge Configuration: {e!s}") from e
 
+    def set_skills(self) -> None:
+        """Resolve skill paths into loaded Skill objects.
+
+        Path entries trigger discovery and activation. Skill entries pass through.
+        Crew-level skill paths are merged in.
+        """
+        crew_skills: list[Path] | None = (
+            self.crew.skills
+            if self.crew and isinstance(self.crew.skills, list)
+            else None
+        )
+
+        if not self.skills and not crew_skills:
+            return
+
+        resolved: list[Path | SkillModel] = []
+        items: list[Path | SkillModel] = list(self.skills) if self.skills else []
+
+        if crew_skills:
+            items.extend(crew_skills)
+
+        for item in items:
+            if isinstance(item, Path):
+                discovered = discover_skills(item, source=self)
+                resolved.extend(activate_skill(s, source=self) for s in discovered)
+            elif isinstance(item, SkillModel):
+                resolved.append(item)
+
+        self.skills = resolved if resolved else None
+
     def _is_any_available_memory(self) -> bool:
         """Check if any memory is available."""
         if not self.crew:
@@ -432,6 +466,8 @@ class Agent(BaseAgent):
             self.crew.query_knowledge if self.crew else lambda *a, **k: None,
         )
 
+        task_prompt = append_skill_context(self, task_prompt)
+
         prepare_tools(self, tools, task)
         task_prompt = apply_training_data(self, task_prompt)
 
@@ -666,6 +702,8 @@ class Agent(BaseAgent):
             self, task, task_prompt, knowledge_config
         )
 
+        task_prompt = append_skill_context(self, task_prompt)
+
         prepare_tools(self, tools, task)
         task_prompt = apply_training_data(self, task_prompt)
 

lib/crewai/src/crewai/agent/utils.py

@@ -203,6 +203,30 @@ def _combine_knowledge_context(agent: Agent) -> str:
     return agent_ctx + separator + crew_ctx
 
 
+def append_skill_context(agent: Agent, task_prompt: str) -> str:
+    """Append activated skill context sections to the task prompt.
+
+    Args:
+        agent: The agent with optional skills.
+        task_prompt: The current task prompt.
+
+    Returns:
+        The task prompt with skill context appended.
+    """
+    if not agent.skills:
+        return task_prompt
+
+    from crewai.skills.loader import format_skill_context
+    from crewai.skills.models import Skill
+
+    skill_sections = [
+        format_skill_context(s) for s in agent.skills if isinstance(s, Skill)
+    ]
+    if skill_sections:
+        task_prompt += "\n\n" + "\n\n".join(skill_sections)
+    return task_prompt
+
+
 def apply_training_data(agent: Agent, task_prompt: str) -> str:
     """Apply training data to the task prompt.
 

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

@@ -4,6 +4,7 @@ from abc import ABC, abstractmethod
 from collections.abc import Callable
 from copy import copy as shallow_copy
 from hashlib import md5
+from pathlib import Path
 from typing import Any, Literal
 import uuid
 
@@ -28,6 +29,7 @@ from crewai.knowledge.source.base_knowledge_source import BaseKnowledgeSource
 from crewai.mcp.config import MCPServerConfig
 from crewai.rag.embeddings.types import EmbedderConfig
 from crewai.security.security_config import SecurityConfig
+from crewai.skills.models import Skill
 from crewai.tools.base_tool import BaseTool, Tool
 from crewai.utilities.config import process_config
 from crewai.utilities.i18n import I18N, get_i18n
@@ -199,6 +201,10 @@ class BaseAgent(BaseModel, ABC, metaclass=AgentMeta):
         default=None,
         description="List of MCP server references. Supports 'https://server.com/path' for external servers and 'crewai-amp:mcp-name' for AMP marketplace. Use '#tool_name' suffix for specific tools.",
     )
+    skills: list[Path | Skill] | None = Field(
+        default=None,
+        description="Agent Skills. Accepts Paths for discovery or pre-loaded Skill objects.",
+    )
 
     @model_validator(mode="before")
     @classmethod
@@ -469,3 +475,6 @@ class BaseAgent(BaseModel, ABC, metaclass=AgentMeta):
 
     def set_knowledge(self, crew_embedder: EmbedderConfig | None = None) -> None:
         pass
+
+    def set_skills(self) -> None:
+        pass

lib/crewai/src/crewai/crew.py

@@ -6,6 +6,7 @@ from concurrent.futures import Future
 from copy import copy as shallow_copy
 from hashlib import md5
 import json
+from pathlib import Path
 import re
 from typing import (
     TYPE_CHECKING,
@@ -311,6 +312,10 @@ class Crew(FlowTrackable, BaseModel):
         default=None,
         description="Knowledge for the crew.",
     )
+    skills: list[Path] | None = Field(
+        default=None,
+        description="Skill search paths applied to all agents in the crew.",
+    )
     security_config: SecurityConfig = Field(
         default_factory=SecurityConfig,
         description="Security configuration for the crew, including fingerprinting.",

lib/crewai/src/crewai/crews/utils.py

@@ -70,6 +70,7 @@ def setup_agents(
     for agent in agents:
         agent.crew = crew
         agent.set_knowledge(crew_embedder=embedder)
+        agent.set_skills()
         if not agent.function_calling_llm:  # type: ignore[attr-defined]
             agent.function_calling_llm = function_calling_llm  # type: ignore[attr-defined]
         if not agent.step_callback:  # type: ignore[attr-defined]

lib/crewai/src/crewai/skills/loader.py

@@ -0,0 +1,170 @@
+"""Filesystem discovery and progressive loading for Agent Skills.
+
+Provides functions to discover skills in directories, activate them
+for agent use, and format skill context for prompt injection.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Any
+
+from crewai.events.event_bus import crewai_event_bus
+from crewai.events.types.skill_events import (
+    SkillActivatedEvent,
+    SkillDiscoveryCompletedEvent,
+    SkillDiscoveryStartedEvent,
+    SkillLoadFailedEvent,
+    SkillLoadedEvent,
+)
+from crewai.skills.models import DisclosureLevel, Skill
+from crewai.skills.parser import (
+    SKILL_FILENAME,
+    load_skill_instructions,
+    load_skill_metadata,
+    load_skill_resources,
+)
+
+
+def discover_skills(
+    search_path: Path,
+    source: Any | None = None,
+) -> list[Skill]:
+    """Scan a directory for skill directories containing SKILL.md.
+
+    Loads each discovered skill at METADATA disclosure level.
+
+    Args:
+        search_path: Directory to scan for skill subdirectories.
+        source: Optional event source (agent or crew) for event emission.
+
+    Returns:
+        List of Skill instances at METADATA level.
+    """
+    skills: list[Skill] = []
+
+    if not search_path.is_dir():
+        return skills
+
+    if source is not None:
+        crewai_event_bus.emit(
+            source,
+            event=SkillDiscoveryStartedEvent(
+                search_path=str(search_path),
+            ),
+        )
+
+    for child in sorted(search_path.iterdir()):
+        if not child.is_dir():
+            continue
+        skill_md = child / SKILL_FILENAME
+        if not skill_md.is_file():
+            continue
+        try:
+            skill = load_skill_metadata(child)
+            skills.append(skill)
+            if source is not None:
+                crewai_event_bus.emit(
+                    source,
+                    event=SkillLoadedEvent(
+                        skill_name=skill.name,
+                        skill_path=str(skill.path),
+                        disclosure_level=skill.disclosure_level.value,
+                    ),
+                )
+        except Exception as e:
+            if source is not None:
+                crewai_event_bus.emit(
+                    source,
+                    event=SkillLoadFailedEvent(
+                        skill_name=child.name,
+                        skill_path=str(child),
+                        error=str(e),
+                    ),
+                )
+
+    if source is not None:
+        crewai_event_bus.emit(
+            source,
+            event=SkillDiscoveryCompletedEvent(
+                search_path=str(search_path),
+                skills_found=len(skills),
+                skill_names=[s.name for s in skills],
+            ),
+        )
+
+    return skills
+
+
+def activate_skill(
+    skill: Skill,
+    source: Any | None = None,
+) -> Skill:
+    """Promote a skill to INSTRUCTIONS disclosure level.
+
+    Idempotent: returns the skill unchanged if already at or above INSTRUCTIONS.
+
+    Args:
+        skill: Skill to activate.
+        source: Optional event source for event emission.
+
+    Returns:
+        Skill at INSTRUCTIONS level or higher.
+    """
+    if skill.disclosure_level >= DisclosureLevel.INSTRUCTIONS:
+        return skill
+
+    activated = load_skill_instructions(skill)
+
+    if source is not None:
+        crewai_event_bus.emit(
+            source,
+            event=SkillActivatedEvent(
+                skill_name=activated.name,
+                skill_path=str(activated.path),
+                disclosure_level=activated.disclosure_level.value,
+            ),
+        )
+
+    return activated
+
+
+def load_resources(skill: Skill) -> Skill:
+    """Promote a skill to RESOURCES disclosure level.
+
+    Args:
+        skill: Skill to promote.
+
+    Returns:
+        Skill at RESOURCES level.
+    """
+    return load_skill_resources(skill)
+
+
+def format_skill_context(skill: Skill) -> str:
+    """Format skill information for agent prompt injection.
+
+    At METADATA level: returns name and description only.
+    At INSTRUCTIONS level or above: returns full SKILL.md body.
+
+    Args:
+        skill: The skill to format.
+
+    Returns:
+        Formatted skill context string.
+    """
+    if skill.disclosure_level >= DisclosureLevel.INSTRUCTIONS and skill.instructions:
+        parts = [
+            f"## Skill: {skill.name}",
+            skill.description,
+            "",
+            skill.instructions,
+        ]
+        if skill.disclosure_level >= DisclosureLevel.RESOURCES and skill.resource_files:
+            parts.append("")
+            parts.append("### Available Resources")
+            for dir_name, files in sorted(skill.resource_files.items()):
+                if files:
+                    parts.append(f"- **{dir_name}/**: {', '.join(files)}")
+        return "\n".join(parts)
+    return f"## Skill: {skill.name}\n{skill.description}"