Phase 3: Skills & Context — skill system, personal context, context layering

Backend: - Skill model + migration (with FK on chats.skill_id) - Personal + general skill CRUD services with access isolation - Admin skill CRUD endpoints (POST/GET/PATCH/DELETE /admin/skills) - User skill CRUD endpoints (POST/GET/PATCH/DELETE /skills/) - Personal context GET/PUT at /users/me/context - Extended context assembly: primary + personal context + skill prompt - Chat creation/update now accepts skill_id with validation Frontend: - Skill selector dropdown in chat header (grouped: general + personal) - Reusable skill editor form component - Admin skills management page (/admin/skills) - Personal skills page (/skills) - Personal context editor page (/profile/context) - Updated sidebar: Skills, My Context nav items + admin skills link - English + Russian translations for all skill/context UI Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-19 12:55:02 +03:00
parent 70469beef8
commit 03afb7a075
33 changed files with 1387 additions and 62 deletions
--- a/GeneralPlan.md
+++ b/GeneralPlan.md
@@ -214,8 +214,8 @@ Daily scheduled job (APScheduler, 8 AM) reviews each user's memory + recent docs
 - Summary: Chats + messages tables, chat CRUD, SSE streaming, Claude API integration, context assembly, frontend chat UI, admin context editor, chat limits

 ### Phase 3: Skills & Context
- **Status**: NOT STARTED
- [ ] Subplan created (`plans/phase-3-skills-context.md`)
+- **Status**: IN PROGRESS
+- [x] Subplan created (`plans/phase-3-skills-context.md`)
 - [ ] Phase completed
 - Summary: Skills + context_files tables, skills CRUD (general + personal), personal context CRUD, context layering, frontend skill selector + editors

--- a/backend/alembic/versions/003_create_skills_add_chat_skill_fk.py
+++ b/backend/alembic/versions/003_create_skills_add_chat_skill_fk.py
@@ -0,0 +1,46 @@
+"""Create skills table and add FK on chats.skill_id
+
+Revision ID: 003
+Revises: 002
+Create Date: 2026-03-19
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects.postgresql import UUID
+
+revision: str = "003"
+down_revision: Union[str, None] = "002"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "skills",
+        sa.Column("id", UUID(as_uuid=True), primary_key=True, server_default=sa.text("gen_random_uuid()")),
+        sa.Column("user_id", UUID(as_uuid=True), sa.ForeignKey("users.id", ondelete="CASCADE"), nullable=True, index=True),
+        sa.Column("name", sa.String(100), nullable=False),
+        sa.Column("description", sa.Text, nullable=True),
+        sa.Column("system_prompt", sa.Text, nullable=False),
+        sa.Column("icon", sa.String(50), nullable=True),
+        sa.Column("is_active", sa.Boolean, nullable=False, server_default=sa.text("true")),
+        sa.Column("sort_order", sa.Integer, nullable=False, server_default=sa.text("0")),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+    )
+
+    op.create_foreign_key(
+        "fk_chats_skill_id",
+        "chats",
+        "skills",
+        ["skill_id"],
+        ["id"],
+        ondelete="SET NULL",
+    )
+
+
+def downgrade() -> None:
+    op.drop_constraint("fk_chats_skill_id", "chats", type_="foreignkey")
+    op.drop_table("skills")
--- a/backend/app/api/v1/admin.py
+++ b/backend/app/api/v1/admin.py
@@ -1,17 +1,26 @@
+import uuid
 from typing import Annotated

-from fastapi import APIRouter, Depends
+from fastapi import APIRouter, Depends, status
 from sqlalchemy.ext.asyncio import AsyncSession

 from app.api.deps import require_admin
 from app.database import get_db
 from app.models.user import User
 from app.schemas.chat import ContextFileResponse, UpdateContextRequest
-from app.services import context_service
+from app.schemas.skill import (
+    CreateSkillRequest,
+    SkillListResponse,
+    SkillResponse,
+    UpdateSkillRequest,
+)
+from app.services import context_service, skill_service

 router = APIRouter(prefix="/admin", tags=["admin"])


+# --- Context ---
+
@router.get("/context", response_model=ContextFileResponse | None)
 async def get_primary_context(
    _admin: Annotated[User, Depends(require_admin)],
@@ -31,3 +40,44 @@ async def update_primary_context(
 ):
    ctx = await context_service.upsert_primary_context(db, data.content, admin.id)
    return ContextFileResponse.model_validate(ctx)
+
+
+# --- Skills ---
+
+@router.get("/skills", response_model=SkillListResponse)
+async def list_general_skills(
+    _admin: Annotated[User, Depends(require_admin)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    skills = await skill_service.get_general_skills(db)
+    return SkillListResponse(skills=[SkillResponse.model_validate(s) for s in skills])
+
+
+@router.post("/skills", response_model=SkillResponse, status_code=status.HTTP_201_CREATED)
+async def create_general_skill(
+    data: CreateSkillRequest,
+    _admin: Annotated[User, Depends(require_admin)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    skill = await skill_service.create_general_skill(db, **data.model_dump())
+    return SkillResponse.model_validate(skill)
+
+
+@router.patch("/skills/{skill_id}", response_model=SkillResponse)
+async def update_general_skill(
+    skill_id: uuid.UUID,
+    data: UpdateSkillRequest,
+    _admin: Annotated[User, Depends(require_admin)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    skill = await skill_service.update_general_skill(db, skill_id, **data.model_dump(exclude_unset=True))
+    return SkillResponse.model_validate(skill)
+
+
+@router.delete("/skills/{skill_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_general_skill(
+    skill_id: uuid.UUID,
+    _admin: Annotated[User, Depends(require_admin)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    await skill_service.delete_general_skill(db, skill_id)
--- a/backend/app/api/v1/chats.py
+++ b/backend/app/api/v1/chats.py
@@ -17,7 +17,7 @@ from app.schemas.chat import (
    SendMessageRequest,
    UpdateChatRequest,
 )
-from app.services import chat_service
+from app.services import chat_service, skill_service
 from app.services.ai_service import stream_ai_response

 router = APIRouter(prefix="/chats", tags=["chats"])
@@ -29,7 +29,9 @@ async def create_chat(
    user: Annotated[User, Depends(get_current_user)],
    db: Annotated[AsyncSession, Depends(get_db)],
 ):
-    chat = await chat_service.create_chat(db, user, data.title)
+    if data.skill_id:
+        await skill_service.validate_skill_accessible(db, data.skill_id, user.id)
+    chat = await chat_service.create_chat(db, user, data.title, data.skill_id)
    return ChatResponse.model_validate(chat)


@@ -60,7 +62,9 @@ async def update_chat(
    user: Annotated[User, Depends(get_current_user)],
    db: Annotated[AsyncSession, Depends(get_db)],
 ):
-    chat = await chat_service.update_chat(db, chat_id, user.id, data.title, data.is_archived)
+    if data.skill_id:
+        await skill_service.validate_skill_accessible(db, data.skill_id, user.id)
+    chat = await chat_service.update_chat(db, chat_id, user.id, data.title, data.is_archived, data.skill_id)
    return ChatResponse.model_validate(chat)


--- a/backend/app/api/v1/router.py
+++ b/backend/app/api/v1/router.py
@@ -3,12 +3,16 @@ from fastapi import APIRouter
 from app.api.v1.auth import router as auth_router
 from app.api.v1.chats import router as chats_router
 from app.api.v1.admin import router as admin_router
+from app.api.v1.skills import router as skills_router
+from app.api.v1.users import router as users_router

 api_v1_router = APIRouter(prefix="/api/v1")

 api_v1_router.include_router(auth_router)
 api_v1_router.include_router(chats_router)
 api_v1_router.include_router(admin_router)
+api_v1_router.include_router(skills_router)
+api_v1_router.include_router(users_router)


@api_v1_router.get("/health")
--- a/backend/app/api/v1/skills.py
+++ b/backend/app/api/v1/skills.py
@@ -0,0 +1,70 @@
+import uuid
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, Query, status
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.api.deps import get_current_user
+from app.database import get_db
+from app.models.user import User
+from app.schemas.skill import (
+    CreateSkillRequest,
+    SkillListResponse,
+    SkillResponse,
+    UpdateSkillRequest,
+)
+from app.services import skill_service
+
+router = APIRouter(prefix="/skills", tags=["skills"])
+
+
+@router.get("/", response_model=SkillListResponse)
+async def list_skills(
+    user: Annotated[User, Depends(get_current_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+    include_general: bool = Query(default=True),
+):
+    skills = await skill_service.get_accessible_skills(db, user.id, include_general)
+    return SkillListResponse(skills=[SkillResponse.model_validate(s) for s in skills])
+
+
+@router.post("/", response_model=SkillResponse, status_code=status.HTTP_201_CREATED)
+async def create_skill(
+    data: CreateSkillRequest,
+    user: Annotated[User, Depends(get_current_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    skill = await skill_service.create_personal_skill(db, user.id, **data.model_dump())
+    return SkillResponse.model_validate(skill)
+
+
+@router.get("/{skill_id}", response_model=SkillResponse)
+async def get_skill(
+    skill_id: uuid.UUID,
+    user: Annotated[User, Depends(get_current_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    skill = await skill_service.get_skill(db, skill_id, user.id)
+    return SkillResponse.model_validate(skill)
+
+
+@router.patch("/{skill_id}", response_model=SkillResponse)
+async def update_skill(
+    skill_id: uuid.UUID,
+    data: UpdateSkillRequest,
+    user: Annotated[User, Depends(get_current_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    skill = await skill_service.update_personal_skill(
+        db, skill_id, user.id, **data.model_dump(exclude_unset=True)
+    )
+    return SkillResponse.model_validate(skill)
+
+
+@router.delete("/{skill_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_skill(
+    skill_id: uuid.UUID,
+    user: Annotated[User, Depends(get_current_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    await skill_service.delete_personal_skill(db, skill_id, user.id)
--- a/backend/app/api/v1/users.py
+++ b/backend/app/api/v1/users.py
@@ -0,0 +1,33 @@
+from typing import Annotated
+
+from fastapi import APIRouter, Depends
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.api.deps import get_current_user
+from app.database import get_db
+from app.models.user import User
+from app.schemas.chat import ContextFileResponse, UpdateContextRequest
+from app.services import context_service
+
+router = APIRouter(prefix="/users", tags=["users"])
+
+
+@router.get("/me/context", response_model=ContextFileResponse | None)
+async def get_personal_context(
+    user: Annotated[User, Depends(get_current_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    ctx = await context_service.get_personal_context(db, user.id)
+    if not ctx:
+        return None
+    return ContextFileResponse.model_validate(ctx)
+
+
+@router.put("/me/context", response_model=ContextFileResponse)
+async def update_personal_context(
+    data: UpdateContextRequest,
+    user: Annotated[User, Depends(get_current_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    ctx = await context_service.upsert_personal_context(db, user.id, data.content)
+    return ContextFileResponse.model_validate(ctx)
--- a/backend/app/models/init.py
+++ b/backend/app/models/init.py
@@ -3,5 +3,6 @@ from app.models.session import Session
 from app.models.chat import Chat
 from app.models.message import Message
 from app.models.context_file import ContextFile
+from app.models.skill import Skill

-__all__ = ["User", "Session", "Chat", "Message", "ContextFile"]
+__all__ = ["User", "Session", "Chat", "Message", "ContextFile", "Skill"]
--- a/backend/app/models/chat.py
+++ b/backend/app/models/chat.py
@@ -15,11 +15,14 @@ class Chat(Base):
        UUID(as_uuid=True), ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
    )
    title: Mapped[str] = mapped_column(String(255), nullable=False, default="New Chat")
-    skill_id: Mapped[uuid.UUID | None] = mapped_column(UUID(as_uuid=True), nullable=True)
+    skill_id: Mapped[uuid.UUID | None] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("skills.id", ondelete="SET NULL"), nullable=True
+    )
    is_archived: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False
    )

    user: Mapped["User"] = relationship(back_populates="chats")  # noqa: F821
+    skill: Mapped["Skill | None"] = relationship()  # noqa: F821
    messages: Mapped[list["Message"]] = relationship(back_populates="chat", cascade="all, delete-orphan")  # noqa: F821
--- a/backend/app/models/skill.py
+++ b/backend/app/models/skill.py
@@ -0,0 +1,23 @@
+import uuid
+
+from sqlalchemy import Boolean, ForeignKey, Integer, String, Text
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.database import Base
+
+
+class Skill(Base):
+    __tablename__ = "skills"
+
+    user_id: Mapped[uuid.UUID | None] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("users.id", ondelete="CASCADE"), nullable=True, index=True
+    )
+    name: Mapped[str] = mapped_column(String(100), nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    system_prompt: Mapped[str] = mapped_column(Text, nullable=False)
+    icon: Mapped[str | None] = mapped_column(String(50), nullable=True)
+    is_active: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
+    sort_order: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+
+    user: Mapped["User | None"] = relationship(back_populates="skills")  # noqa: F821
--- a/backend/app/models/user.py
+++ b/backend/app/models/user.py
@@ -26,3 +26,4 @@ class User(Base):

    sessions: Mapped[list["Session"]] = relationship(back_populates="user", cascade="all, delete-orphan")  # noqa: F821
    chats: Mapped[list["Chat"]] = relationship(back_populates="user", cascade="all, delete-orphan")  # noqa: F821
+    skills: Mapped[list["Skill"]] = relationship(back_populates="user", cascade="all, delete-orphan")  # noqa: F821
--- a/backend/app/schemas/chat.py
+++ b/backend/app/schemas/chat.py
@@ -6,11 +6,13 @@ from pydantic import BaseModel, Field

 class CreateChatRequest(BaseModel):
    title: str | None = None
+    skill_id: uuid.UUID | None = None


 class UpdateChatRequest(BaseModel):
    title: str | None = None
    is_archived: bool | None = None
+    skill_id: uuid.UUID | None = None


 class SendMessageRequest(BaseModel):
--- a/backend/app/schemas/skill.py
+++ b/backend/app/schemas/skill.py
@@ -0,0 +1,40 @@
+import uuid
+from datetime import datetime
+
+from pydantic import BaseModel, Field
+
+
+class CreateSkillRequest(BaseModel):
+    name: str = Field(min_length=1, max_length=100)
+    description: str | None = None
+    system_prompt: str = Field(min_length=1)
+    icon: str | None = None
+    is_active: bool = True
+    sort_order: int = 0
+
+
+class UpdateSkillRequest(BaseModel):
+    name: str | None = Field(default=None, min_length=1, max_length=100)
+    description: str | None = None
+    system_prompt: str | None = Field(default=None, min_length=1)
+    icon: str | None = None
+    is_active: bool | None = None
+    sort_order: int | None = None
+
+
+class SkillResponse(BaseModel):
+    id: uuid.UUID
+    user_id: uuid.UUID | None
+    name: str
+    description: str | None
+    system_prompt: str
+    icon: str | None
+    is_active: bool
+    sort_order: int
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class SkillListResponse(BaseModel):
+    skills: list[SkillResponse]
--- a/backend/app/services/ai_service.py
+++ b/backend/app/services/ai_service.py
@@ -9,31 +9,48 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.config import settings
 from app.models.chat import Chat
 from app.models.message import Message
-from app.services.context_service import DEFAULT_SYSTEM_PROMPT, get_primary_context
+from app.models.skill import Skill
+from app.services.context_service import DEFAULT_SYSTEM_PROMPT, get_primary_context, get_personal_context
 from app.services.chat_service import get_chat, save_message

 client = AsyncAnthropic(api_key=settings.ANTHROPIC_API_KEY)


 async def assemble_context(
-    db: AsyncSession, chat_id: uuid.UUID, user_message: str
+    db: AsyncSession, chat_id: uuid.UUID, user_id: uuid.UUID, user_message: str
 ) -> tuple[str, list[dict]]:
    """Assemble system prompt and messages for Claude API."""
+    system_parts = []
+
    # 1. Primary context
    ctx = await get_primary_context(db)
-    system_prompt = ctx.content if ctx and ctx.content.strip() else DEFAULT_SYSTEM_PROMPT
+    system_parts.append(ctx.content if ctx and ctx.content.strip() else DEFAULT_SYSTEM_PROMPT)

-    # 2. Conversation history
+    # 2. Personal context
+    personal_ctx = await get_personal_context(db, user_id)
+    if personal_ctx and personal_ctx.content.strip():
+        system_parts.append(f"---\nUser Context:\n{personal_ctx.content}")
+
+    # 3. Active skill system prompt
+    chat = await get_chat(db, chat_id, user_id)
+    if chat.skill_id:
+        result = await db.execute(select(Skill).where(Skill.id == chat.skill_id))
+        skill = result.scalar_one_or_none()
+        if skill and skill.is_active:
+            system_parts.append(f"---\nSpecialist Role ({skill.name}):\n{skill.system_prompt}")
+
+    system_prompt = "\n\n".join(system_parts)
+
+    # 4. Conversation history
    result = await db.execute(
        select(Message)
        .where(Message.chat_id == chat_id, Message.role.in_(["user", "assistant"]))
        .order_by(Message.created_at.asc())
    )
    history = result.scalars().all()
-
    messages = [{"role": msg.role, "content": msg.content} for msg in history]

-    # 3. Current user message
+    # 5. Current user message
    messages.append({"role": "user", "content": user_message})

    return system_prompt, messages
@@ -56,7 +73,7 @@ async def stream_ai_response(

    try:
        # Assemble context
-        system_prompt, messages = await assemble_context(db, chat_id, user_message)
+        system_prompt, messages = await assemble_context(db, chat_id, user_id, user_message)

        # Stream from Claude
        full_content = ""
--- a/backend/app/services/chat_service.py
+++ b/backend/app/services/chat_service.py
@@ -9,7 +9,7 @@ from app.models.message import Message
 from app.models.user import User


-async def create_chat(db: AsyncSession, user: User, title: str | None = None) -> Chat:
+async def create_chat(db: AsyncSession, user: User, title: str | None = None, skill_id: uuid.UUID | None = None) -> Chat:
    count = await db.scalar(
        select(func.count()).select_from(Chat).where(
            Chat.user_id == user.id, Chat.is_archived == False  # noqa: E712
@@ -21,7 +21,7 @@ async def create_chat(db: AsyncSession, user: User, title: str | None = None) ->
            detail="Chat limit reached. Archive or delete existing chats.",
        )

-    chat = Chat(user_id=user.id, title=title or "New Chat")
+    chat = Chat(user_id=user.id, title=title or "New Chat", skill_id=skill_id)
    db.add(chat)
    await db.flush()
    return chat
@@ -51,12 +51,15 @@ async def get_chat(db: AsyncSession, chat_id: uuid.UUID, user_id: uuid.UUID) ->
 async def update_chat(
    db: AsyncSession, chat_id: uuid.UUID, user_id: uuid.UUID,
    title: str | None = None, is_archived: bool | None = None,
+    skill_id: uuid.UUID | None = None,
 ) -> Chat:
    chat = await get_chat(db, chat_id, user_id)
    if title is not None:
        chat.title = title
    if is_archived is not None:
        chat.is_archived = is_archived
+    if skill_id is not None:
+        chat.skill_id = skill_id
    await db.flush()
    return chat

--- a/backend/app/services/context_service.py
+++ b/backend/app/services/context_service.py
@@ -23,6 +23,34 @@ async def get_primary_context(db: AsyncSession) -> ContextFile | None:
    return result.scalar_one_or_none()


+async def get_personal_context(db: AsyncSession, user_id: uuid.UUID) -> ContextFile | None:
+    result = await db.execute(
+        select(ContextFile).where(ContextFile.type == "personal", ContextFile.user_id == user_id)
+    )
+    return result.scalar_one_or_none()
+
+
+async def upsert_personal_context(
+    db: AsyncSession, user_id: uuid.UUID, content: str
+) -> ContextFile:
+    ctx = await get_personal_context(db, user_id)
+    if ctx:
+        ctx.content = content
+        ctx.version = ctx.version + 1
+        ctx.updated_by = user_id
+    else:
+        ctx = ContextFile(
+            type="personal",
+            user_id=user_id,
+            content=content,
+            version=1,
+            updated_by=user_id,
+        )
+        db.add(ctx)
+    await db.flush()
+    return ctx
+
+
 async def upsert_primary_context(
    db: AsyncSession, content: str, admin_user_id: uuid.UUID
 ) -> ContextFile:
--- a/backend/app/services/skill_service.py
+++ b/backend/app/services/skill_service.py
@@ -0,0 +1,97 @@
+import uuid
+
+from fastapi import HTTPException, status
+from sqlalchemy import or_, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.skill import Skill
+
+
+async def get_accessible_skills(
+    db: AsyncSession, user_id: uuid.UUID, include_general: bool = True
+) -> list[Skill]:
+    conditions = [Skill.user_id == user_id]
+    if include_general:
+        conditions.append(Skill.user_id.is_(None))
+    stmt = select(Skill).where(or_(*conditions), Skill.is_active == True).order_by(Skill.sort_order)  # noqa: E712
+    result = await db.execute(stmt)
+    return list(result.scalars().all())
+
+
+async def get_skill(db: AsyncSession, skill_id: uuid.UUID, user_id: uuid.UUID | None = None) -> Skill:
+    result = await db.execute(select(Skill).where(Skill.id == skill_id))
+    skill = result.scalar_one_or_none()
+    if not skill:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Skill not found")
+    # Access check: must be general or owned by user
+    if user_id and skill.user_id is not None and skill.user_id != user_id:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Skill not found")
+    return skill
+
+
+async def validate_skill_accessible(db: AsyncSession, skill_id: uuid.UUID, user_id: uuid.UUID) -> None:
+    """Validate skill exists and is accessible by user (general or owned). Raises 404 if not."""
+    await get_skill(db, skill_id, user_id)
+
+
+# --- Personal skills ---
+
+async def create_personal_skill(db: AsyncSession, user_id: uuid.UUID, **kwargs) -> Skill:
+    skill = Skill(user_id=user_id, **kwargs)
+    db.add(skill)
+    await db.flush()
+    return skill
+
+
+async def update_personal_skill(db: AsyncSession, skill_id: uuid.UUID, user_id: uuid.UUID, **kwargs) -> Skill:
+    skill = await get_skill(db, skill_id, user_id)
+    if skill.user_id != user_id:
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Cannot edit general skills")
+    for key, value in kwargs.items():
+        if value is not None:
+            setattr(skill, key, value)
+    await db.flush()
+    return skill
+
+
+async def delete_personal_skill(db: AsyncSession, skill_id: uuid.UUID, user_id: uuid.UUID) -> None:
+    skill = await get_skill(db, skill_id, user_id)
+    if skill.user_id != user_id:
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Cannot delete general skills")
+    await db.delete(skill)
+
+
+# --- General (admin) skills ---
+
+async def get_general_skills(db: AsyncSession) -> list[Skill]:
+    result = await db.execute(
+        select(Skill).where(Skill.user_id.is_(None)).order_by(Skill.sort_order)
+    )
+    return list(result.scalars().all())
+
+
+async def create_general_skill(db: AsyncSession, **kwargs) -> Skill:
+    skill = Skill(user_id=None, **kwargs)
+    db.add(skill)
+    await db.flush()
+    return skill
+
+
+async def update_general_skill(db: AsyncSession, skill_id: uuid.UUID, **kwargs) -> Skill:
+    result = await db.execute(select(Skill).where(Skill.id == skill_id, Skill.user_id.is_(None)))
+    skill = result.scalar_one_or_none()
+    if not skill:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="General skill not found")
+    for key, value in kwargs.items():
+        if value is not None:
+            setattr(skill, key, value)
+    await db.flush()
+    return skill
+
+
+async def delete_general_skill(db: AsyncSession, skill_id: uuid.UUID) -> None:
+    result = await db.execute(select(Skill).where(Skill.id == skill_id, Skill.user_id.is_(None)))
+    skill = result.scalar_one_or_none()
+    if not skill:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="General skill not found")
+    await db.delete(skill)
--- a/backend/tests/test_skills.py
+++ b/backend/tests/test_skills.py
@@ -0,0 +1,142 @@
+import pytest
+from httpx import AsyncClient
+
+
+@pytest.fixture
+async def user_headers(client: AsyncClient):
+    resp = await client.post("/api/v1/auth/register", json={
+        "email": "skilluser@example.com",
+        "username": "skilluser",
+        "password": "testpass123",
+    })
+    assert resp.status_code == 201
+    return {"Authorization": f"Bearer {resp.json()['access_token']}"}
+
+
+@pytest.fixture
+async def other_user_headers(client: AsyncClient):
+    resp = await client.post("/api/v1/auth/register", json={
+        "email": "skillother@example.com",
+        "username": "skillother",
+        "password": "testpass123",
+    })
+    assert resp.status_code == 201
+    return {"Authorization": f"Bearer {resp.json()['access_token']}"}
+
+
+# --- Personal Skills ---
+
+async def test_create_personal_skill(client: AsyncClient, user_headers: dict):
+    resp = await client.post("/api/v1/skills/", json={
+        "name": "Nutritionist",
+        "description": "Diet and nutrition advice",
+        "system_prompt": "You are a nutritionist.",
+    }, headers=user_headers)
+    assert resp.status_code == 201
+    data = resp.json()
+    assert data["name"] == "Nutritionist"
+    assert data["user_id"] is not None
+
+
+async def test_list_personal_skills(client: AsyncClient, user_headers: dict):
+    await client.post("/api/v1/skills/", json={
+        "name": "Test Skill",
+        "system_prompt": "Test prompt",
+    }, headers=user_headers)
+
+    resp = await client.get("/api/v1/skills/", params={"include_general": False}, headers=user_headers)
+    assert resp.status_code == 200
+    assert len(resp.json()["skills"]) >= 1
+
+
+async def test_update_personal_skill(client: AsyncClient, user_headers: dict):
+    resp = await client.post("/api/v1/skills/", json={
+        "name": "Old Name",
+        "system_prompt": "Prompt",
+    }, headers=user_headers)
+    skill_id = resp.json()["id"]
+
+    resp = await client.patch(f"/api/v1/skills/{skill_id}", json={
+        "name": "New Name",
+    }, headers=user_headers)
+    assert resp.status_code == 200
+    assert resp.json()["name"] == "New Name"
+
+
+async def test_delete_personal_skill(client: AsyncClient, user_headers: dict):
+    resp = await client.post("/api/v1/skills/", json={
+        "name": "To Delete",
+        "system_prompt": "Prompt",
+    }, headers=user_headers)
+    skill_id = resp.json()["id"]
+
+    resp = await client.delete(f"/api/v1/skills/{skill_id}", headers=user_headers)
+    assert resp.status_code == 204
+
+
+async def test_cannot_access_other_users_skill(client: AsyncClient, user_headers: dict, other_user_headers: dict):
+    resp = await client.post("/api/v1/skills/", json={
+        "name": "Private Skill",
+        "system_prompt": "Prompt",
+    }, headers=user_headers)
+    skill_id = resp.json()["id"]
+
+    # Other user can't see it
+    resp = await client.get(f"/api/v1/skills/{skill_id}", headers=other_user_headers)
+    assert resp.status_code == 404
+
+
+# --- Admin Skills ---
+
+async def test_non_admin_cannot_manage_general_skills(client: AsyncClient, user_headers: dict):
+    resp = await client.get("/api/v1/admin/skills", headers=user_headers)
+    assert resp.status_code == 403
+
+    resp = await client.post("/api/v1/admin/skills", json={
+        "name": "General",
+        "system_prompt": "Prompt",
+    }, headers=user_headers)
+    assert resp.status_code == 403
+
+
+# --- Personal Context ---
+
+async def test_personal_context_crud(client: AsyncClient, user_headers: dict):
+    # Initially null
+    resp = await client.get("/api/v1/users/me/context", headers=user_headers)
+    assert resp.status_code == 200
+
+    # Create
+    resp = await client.put("/api/v1/users/me/context", json={
+        "content": "I have diabetes type 2",
+    }, headers=user_headers)
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["content"] == "I have diabetes type 2"
+    assert data["version"] == 1
+
+    # Update
+    resp = await client.put("/api/v1/users/me/context", json={
+        "content": "I have diabetes type 2 and hypertension",
+    }, headers=user_headers)
+    assert resp.status_code == 200
+    assert resp.json()["version"] == 2
+
+
+# --- Chat with Skill ---
+
+async def test_create_chat_with_skill(client: AsyncClient, user_headers: dict):
+    # Create a skill first
+    resp = await client.post("/api/v1/skills/", json={
+        "name": "Cardiologist",
+        "system_prompt": "You are a cardiologist.",
+    }, headers=user_headers)
+    skill_id = resp.json()["id"]
+
+    # Create chat with skill
+    resp = await client.post("/api/v1/chats/", json={
+        "title": "Heart Consultation",
+        "skill_id": skill_id,
+    }, headers=user_headers)
+    assert resp.status_code == 201
+    assert resp.json()["skill_id"] == skill_id
--- a/frontend/public/locales/en/translation.json
+++ b/frontend/public/locales/en/translation.json
@@ -36,7 +36,8 @@
    "admin": "Admin",
    "users": "Users",
    "context": "Context",
-    "skills": "Skills"
+    "skills": "Skills",
+    "personal_context": "My Context"
  },
  "dashboard": {
    "welcome": "Welcome, {{name}}",
@@ -64,6 +65,31 @@
    "version": "Version",
    "characters": "characters"
  },
+  "skills": {
+    "my_skills": "My Skills",
+    "general_skills": "General Skills",
+    "no_skills": "No skills yet.",
+    "no_personal_skills": "You haven't created any personal skills yet.",
+    "create_personal": "Create Personal Skill",
+    "edit_personal": "Edit Personal Skill",
+    "create_general": "Create General Skill",
+    "edit_general": "Edit General Skill",
+    "name": "Name",
+    "name_placeholder": "e.g. Cardiologist",
+    "description": "Description",
+    "description_placeholder": "Brief description of this specialist",
+    "system_prompt": "System Prompt",
+    "prompt_placeholder": "Instructions for the AI when using this skill...",
+    "icon": "Icon",
+    "no_skill": "No specialist",
+    "general": "General",
+    "personal": "Personal"
+  },
+  "personal_context": {
+    "title": "Personal Context",
+    "subtitle": "This context is added to all your AI conversations",
+    "placeholder": "Add personal information that the AI should know about you..."
+  },
  "common": {
    "loading": "Loading...",
    "error": "An error occurred",
--- a/frontend/public/locales/ru/translation.json
+++ b/frontend/public/locales/ru/translation.json
@@ -36,7 +36,8 @@
    "admin": "Администрирование",
    "users": "Пользователи",
    "context": "Контекст",
-    "skills": "Навыки"
+    "skills": "Навыки",
+    "personal_context": "Мой контекст"
  },
  "dashboard": {
    "welcome": "Добро пожаловать, {{name}}",
@@ -64,6 +65,31 @@
    "version": "Версия",
    "characters": "символов"
  },
+  "skills": {
+    "my_skills": "Мои навыки",
+    "general_skills": "Общие навыки",
+    "no_skills": "Навыков пока нет.",
+    "no_personal_skills": "Вы ещё не создали персональных навыков.",
+    "create_personal": "Создать персональный навык",
+    "edit_personal": "Редактировать навык",
+    "create_general": "Создать общий навык",
+    "edit_general": "Редактировать общий навык",
+    "name": "Название",
+    "name_placeholder": "напр. Кардиолог",
+    "description": "Описание",
+    "description_placeholder": "Краткое описание специалиста",
+    "system_prompt": "Системный промпт",
+    "prompt_placeholder": "Инструкции для ИИ при использовании этого навыка...",
+    "icon": "Иконка",
+    "no_skill": "Без специалиста",
+    "general": "Общие",
+    "personal": "Персональные"
+  },
+  "personal_context": {
+    "title": "Персональный контекст",
+    "subtitle": "Этот контекст добавляется ко всем вашим разговорам с ИИ",
+    "placeholder": "Добавьте личную информацию, которую ИИ должен знать о вас..."
+  },
  "common": {
    "loading": "Загрузка...",
    "error": "Произошла ошибка",
--- a/frontend/src/api/chats.ts
+++ b/frontend/src/api/chats.ts
@@ -46,7 +46,7 @@ export async function getChat(chatId: string): Promise<Chat> {

 export async function updateChat(
  chatId: string,
-  updates: { title?: string; is_archived?: boolean }
+  updates: { title?: string; is_archived?: boolean; skill_id?: string }
 ): Promise<Chat> {
  const { data } = await api.patch<Chat>(`/chats/${chatId}`, updates);
  return data;
--- a/frontend/src/api/skills.ts
+++ b/frontend/src/api/skills.ts
@@ -0,0 +1,93 @@
+import api from "./client";
+
+export interface Skill {
+  id: string;
+  user_id: string | null;
+  name: string;
+  description: string | null;
+  system_prompt: string;
+  icon: string | null;
+  is_active: boolean;
+  sort_order: number;
+  created_at: string;
+}
+
+export interface SkillListResponse {
+  skills: Skill[];
+}
+
+export async function getSkills(includeGeneral = true): Promise<Skill[]> {
+  const { data } = await api.get<SkillListResponse>("/skills/", {
+    params: { include_general: includeGeneral },
+  });
+  return data.skills;
+}
+
+export async function getSkill(skillId: string): Promise<Skill> {
+  const { data } = await api.get<Skill>(`/skills/${skillId}`);
+  return data;
+}
+
+export async function createSkill(skill: {
+  name: string;
+  description?: string;
+  system_prompt: string;
+  icon?: string;
+}): Promise<Skill> {
+  const { data } = await api.post<Skill>("/skills/", skill);
+  return data;
+}
+
+export async function updateSkill(
+  skillId: string,
+  updates: Partial<{
+    name: string;
+    description: string;
+    system_prompt: string;
+    icon: string;
+    is_active: boolean;
+    sort_order: number;
+  }>
+): Promise<Skill> {
+  const { data } = await api.patch<Skill>(`/skills/${skillId}`, updates);
+  return data;
+}
+
+export async function deleteSkill(skillId: string): Promise<void> {
+  await api.delete(`/skills/${skillId}`);
+}
+
+// Admin skill functions
+export async function getGeneralSkills(): Promise<Skill[]> {
+  const { data } = await api.get<SkillListResponse>("/admin/skills");
+  return data.skills;
+}
+
+export async function createGeneralSkill(skill: {
+  name: string;
+  description?: string;
+  system_prompt: string;
+  icon?: string;
+}): Promise<Skill> {
+  const { data } = await api.post<Skill>("/admin/skills", skill);
+  return data;
+}
+
+export async function updateGeneralSkill(
+  skillId: string,
+  updates: Partial<{
+    name: string;
+    description: string;
+    system_prompt: string;
+    icon: string;
+    is_active: boolean;
+    sort_order: number;
+  }>
+): Promise<Skill> {
+  const { data } = await api.patch<Skill>(`/admin/skills/${skillId}`, updates);
+  return data;
+}
+
+export async function deleteGeneralSkill(skillId: string): Promise<void> {
+  await api.delete(`/admin/skills/${skillId}`);
+}
--- a/frontend/src/api/user-context.ts
+++ b/frontend/src/api/user-context.ts
@@ -0,0 +1,14 @@
+import api from "./client";
+import type { ContextFile } from "./admin";
+
+export async function getPersonalContext(): Promise<ContextFile | null> {
+  const { data } = await api.get<ContextFile | null>("/users/me/context");
+  return data;
+}
+
+export async function updatePersonalContext(
+  content: string
+): Promise<ContextFile> {
+  const { data } = await api.put<ContextFile>("/users/me/context", { content });
+  return data;
+}
--- a/frontend/src/components/admin/skill-editor.tsx
+++ b/frontend/src/components/admin/skill-editor.tsx
@@ -0,0 +1,97 @@
+import { useState, useEffect } from "react";
+import { useTranslation } from "react-i18next";
+import type { Skill } from "@/api/skills";
+
+interface SkillEditorProps {
+  skill?: Skill | null;
+  onSave: (data: { name: string; description: string; system_prompt: string; icon: string }) => void;
+  onCancel: () => void;
+  loading?: boolean;
+}
+
+export function SkillEditor({ skill, onSave, onCancel, loading }: SkillEditorProps) {
+  const { t } = useTranslation();
+  const [name, setName] = useState("");
+  const [description, setDescription] = useState("");
+  const [systemPrompt, setSystemPrompt] = useState("");
+  const [icon, setIcon] = useState("");
+
+  useEffect(() => {
+    if (skill) {
+      setName(skill.name);
+      setDescription(skill.description || "");
+      setSystemPrompt(skill.system_prompt);
+      setIcon(skill.icon || "");
+    }
+  }, [skill]);
+
+  const handleSubmit = (e: React.FormEvent) => {
+    e.preventDefault();
+    onSave({ name, description, system_prompt: systemPrompt, icon });
+  };
+
+  return (
+    <form onSubmit={handleSubmit} className="space-y-4">
+      <div className="space-y-2">
+        <label className="text-sm font-medium">{t("skills.name")}</label>
+        <input
+          value={name}
+          onChange={(e) => setName(e.target.value)}
+          required
+          maxLength={100}
+          className="flex h-10 w-full rounded-md border border-input bg-background px-3 py-2 text-sm ring-offset-background focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
+          placeholder={t("skills.name_placeholder")}
+        />
+      </div>
+
+      <div className="space-y-2">
+        <label className="text-sm font-medium">{t("skills.description")}</label>
+        <input
+          value={description}
+          onChange={(e) => setDescription(e.target.value)}
+          className="flex h-10 w-full rounded-md border border-input bg-background px-3 py-2 text-sm ring-offset-background focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
+          placeholder={t("skills.description_placeholder")}
+        />
+      </div>
+
+      <div className="space-y-2">
+        <label className="text-sm font-medium">{t("skills.system_prompt")}</label>
+        <textarea
+          value={systemPrompt}
+          onChange={(e) => setSystemPrompt(e.target.value)}
+          required
+          rows={8}
+          className="w-full resize-y rounded-md border border-input bg-background px-3 py-2 text-sm font-mono ring-offset-background focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
+          placeholder={t("skills.prompt_placeholder")}
+        />
+      </div>
+
+      <div className="space-y-2">
+        <label className="text-sm font-medium">{t("skills.icon")}</label>
+        <input
+          value={icon}
+          onChange={(e) => setIcon(e.target.value)}
+          className="flex h-10 w-full rounded-md border border-input bg-background px-3 py-2 text-sm ring-offset-background focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
+          placeholder="e.g. heart, brain, stethoscope"
+        />
+      </div>
+
+      <div className="flex justify-end gap-2 pt-2">
+        <button
+          type="button"
+          onClick={onCancel}
+          className="inline-flex h-9 items-center rounded-md border px-4 text-sm font-medium hover:bg-accent transition-colors"
+        >
+          {t("common.cancel")}
+        </button>
+        <button
+          type="submit"
+          disabled={loading || !name.trim() || !systemPrompt.trim()}
+          className="inline-flex h-9 items-center rounded-md bg-primary px-4 text-sm font-medium text-primary-foreground hover:bg-primary/90 disabled:opacity-50 transition-colors"
+        >
+          {loading ? t("common.loading") : t("common.save")}
+        </button>
+      </div>
+    </form>
+  );
+}
--- a/frontend/src/components/chat/chat-window.tsx
+++ b/frontend/src/components/chat/chat-window.tsx
@@ -2,14 +2,17 @@ import { useEffect, useRef } from "react";
 import { useTranslation } from "react-i18next";
 import { MessageBubble } from "./message-bubble";
 import { MessageInput } from "./message-input";
+import { SkillSelector } from "./skill-selector";
 import { useChatStore } from "@/stores/chat-store";
 import { MessageSquare } from "lucide-react";

 interface ChatWindowProps {
  onSendMessage: (content: string) => void;
+  onChangeSkill?: (skillId: string | null) => void;
+  currentSkillId?: string | null;
 }

-export function ChatWindow({ onSendMessage }: ChatWindowProps) {
+export function ChatWindow({ onSendMessage, onChangeSkill, currentSkillId }: ChatWindowProps) {
  const { t } = useTranslation();
  const { messages, isStreaming, streamingContent, currentChatId } = useChatStore();
  const bottomRef = useRef<HTMLDivElement>(null);
@@ -29,6 +32,17 @@ export function ChatWindow({ onSendMessage }: ChatWindowProps) {

  return (
    <div className="flex h-full flex-col">
+      {onChangeSkill && (
+        <div className="flex items-center gap-2 border-b px-4 py-2">
+          <div className="w-48">
+            <SkillSelector
+              value={currentSkillId ?? null}
+              onChange={onChangeSkill}
+              disabled={isStreaming}
+            />
+          </div>
+        </div>
+      )}
      <div className="flex-1 overflow-y-auto p-4 space-y-4">
        {messages.length === 0 && !isStreaming && (
          <div className="flex h-full items-center justify-center">
--- a/frontend/src/components/chat/skill-selector.tsx
+++ b/frontend/src/components/chat/skill-selector.tsx
@@ -0,0 +1,54 @@
+import { useTranslation } from "react-i18next";
+import { useQuery } from "@tanstack/react-query";
+import { getSkills } from "@/api/skills";
+import { Sparkles } from "lucide-react";
+
+interface SkillSelectorProps {
+  value: string | null;
+  onChange: (skillId: string | null) => void;
+  disabled?: boolean;
+}
+
+export function SkillSelector({ value, onChange, disabled }: SkillSelectorProps) {
+  const { t } = useTranslation();
+
+  const { data: skills = [] } = useQuery({
+    queryKey: ["skills"],
+    queryFn: () => getSkills(true),
+  });
+
+  const generalSkills = skills.filter((s) => s.user_id === null);
+  const personalSkills = skills.filter((s) => s.user_id !== null);
+
+  return (
+    <div className="relative">
+      <select
+        value={value || ""}
+        onChange={(e) => onChange(e.target.value || null)}
+        disabled={disabled}
+        className="flex h-9 w-full items-center rounded-md border border-input bg-background px-3 py-1 text-sm ring-offset-background focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring disabled:opacity-50 appearance-none pr-8"
+      >
+        <option value="">{t("skills.no_skill")}</option>
+        {generalSkills.length > 0 && (
+          <optgroup label={t("skills.general")}>
+            {generalSkills.map((s) => (
+              <option key={s.id} value={s.id}>
+                {s.name}
+              </option>
+            ))}
+          </optgroup>
+        )}
+        {personalSkills.length > 0 && (
+          <optgroup label={t("skills.personal")}>
+            {personalSkills.map((s) => (
+              <option key={s.id} value={s.id}>
+                {s.name}
+              </option>
+            ))}
+          </optgroup>
+        )}
+      </select>
+      <Sparkles className="absolute right-2 top-2.5 h-4 w-4 text-muted-foreground pointer-events-none" />
+    </div>
+  );
+}
--- a/frontend/src/components/layout/sidebar.tsx
+++ b/frontend/src/components/layout/sidebar.tsx
@@ -3,21 +3,30 @@ import { NavLink } from "react-router-dom";
 import {
  LayoutDashboard,
  MessageSquare,
+  Sparkles,
  FileText,
  Brain,
  Bell,
  Shield,
+  BookOpen,
 } from "lucide-react";
 import { useAuthStore } from "@/stores/auth-store";
 import { useUIStore } from "@/stores/ui-store";
 import { cn } from "@/lib/utils";

 const navItems = [
-  { key: "dashboard", to: "/", icon: LayoutDashboard, enabled: true },
-  { key: "chats", to: "/chat", icon: MessageSquare, enabled: true },
-  { key: "documents", to: "/documents", icon: FileText, enabled: false },
-  { key: "memory", to: "/memory", icon: Brain, enabled: false },
-  { key: "notifications", to: "/notifications", icon: Bell, enabled: false },
+  { key: "dashboard", to: "/", icon: LayoutDashboard, enabled: true, end: true },
+  { key: "chats", to: "/chat", icon: MessageSquare, enabled: true, end: false },
+  { key: "skills", to: "/skills", icon: Sparkles, enabled: true, end: true },
+  { key: "personal_context", to: "/profile/context", icon: BookOpen, enabled: true, end: true },
+  { key: "documents", to: "/documents", icon: FileText, enabled: false, end: true },
+  { key: "memory", to: "/memory", icon: Brain, enabled: false, end: true },
+  { key: "notifications", to: "/notifications", icon: Bell, enabled: false, end: true },
+];
+
+const adminItems = [
+  { key: "admin_context", to: "/admin/context", label: "layout.context" },
+  { key: "admin_skills", to: "/admin/skills", label: "layout.skills" },
 ];

 export function Sidebar() {
@@ -25,6 +34,15 @@ export function Sidebar() {
  const user = useAuthStore((s) => s.user);
  const sidebarOpen = useUIStore((s) => s.sidebarOpen);

+  const linkClass = ({ isActive }: { isActive: boolean }) =>
+    cn(
+      "flex items-center gap-3 rounded-lg px-3 py-2 text-sm transition-colors",
+      isActive
+        ? "bg-primary/10 text-primary font-medium"
+        : "text-muted-foreground hover:bg-accent hover:text-foreground",
+      !sidebarOpen && "justify-center px-2"
+    );
+
  return (
    <aside
      className={cn(
@@ -33,10 +51,9 @@ export function Sidebar() {
      )}
    >
      <div className="flex h-14 items-center border-b px-4">
-        {sidebarOpen && (
+        {sidebarOpen ? (
          <span className="text-lg font-semibold text-primary">AI Assistant</span>
-        )}
-        {!sidebarOpen && (
+        ) : (
          <span className="text-lg font-semibold text-primary mx-auto">AI</span>
        )}
      </div>
@@ -60,20 +77,7 @@ export function Sidebar() {
          }

          return (
-            <NavLink
-              key={item.key}
-              to={item.to}
-              end
-              className={({ isActive }) =>
-                cn(
-                  "flex items-center gap-3 rounded-lg px-3 py-2 text-sm transition-colors",
-                  isActive
-                    ? "bg-primary/10 text-primary font-medium"
-                    : "text-muted-foreground hover:bg-accent hover:text-foreground",
-                  !sidebarOpen && "justify-center px-2"
-                )
-              }
-            >
+            <NavLink key={item.key} to={item.to} end={item.end} className={linkClass}>
              <Icon className="h-5 w-5 shrink-0" />
              {sidebarOpen && <span>{t(`layout.${item.key}`)}</span>}
            </NavLink>
@@ -82,22 +86,18 @@ export function Sidebar() {
      </nav>

      {user?.role === "admin" && (
-        <div className="border-t p-2">
-          <NavLink
-            to="/admin/context"
-            className={({ isActive }) =>
-              cn(
-                "flex items-center gap-3 rounded-lg px-3 py-2 text-sm transition-colors",
-                isActive
-                  ? "bg-primary/10 text-primary font-medium"
-                  : "text-muted-foreground hover:bg-accent hover:text-foreground",
-                !sidebarOpen && "justify-center px-2"
-              )
-            }
-          >
-            <Shield className="h-5 w-5 shrink-0" />
-            {sidebarOpen && <span>{t("layout.admin")}</span>}
-          </NavLink>
+        <div className="border-t p-2 space-y-1">
+          {sidebarOpen && (
+            <p className="px-3 py-1 text-xs font-semibold text-muted-foreground uppercase tracking-wider">
+              {t("layout.admin")}
+            </p>
+          )}
+          {adminItems.map((item) => (
+            <NavLink key={item.key} to={item.to} className={linkClass}>
+              <Shield className="h-5 w-5 shrink-0" />
+              {sidebarOpen && <span>{t(item.label)}</span>}
+            </NavLink>
+          ))}
        </div>
      )}
    </aside>
--- a/frontend/src/pages/admin/skills.tsx
+++ b/frontend/src/pages/admin/skills.tsx
@@ -0,0 +1,114 @@
+import { useState } from "react";
+import { Navigate } from "react-router-dom";
+import { useTranslation } from "react-i18next";
+import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
+import { useAuthStore } from "@/stores/auth-store";
+import {
+  getGeneralSkills,
+  createGeneralSkill,
+  updateGeneralSkill,
+  deleteGeneralSkill,
+  type Skill,
+} from "@/api/skills";
+import { SkillEditor } from "@/components/admin/skill-editor";
+import { Plus, Pencil, Trash2, Sparkles } from "lucide-react";
+
+export function AdminSkillsPage() {
+  const { t } = useTranslation();
+  const user = useAuthStore((s) => s.user);
+  const queryClient = useQueryClient();
+  const [editing, setEditing] = useState<Skill | null>(null);
+  const [creating, setCreating] = useState(false);
+
+  if (user?.role !== "admin") return <Navigate to="/" replace />;
+
+  const { data: skills = [] } = useQuery({
+    queryKey: ["admin-skills"],
+    queryFn: getGeneralSkills,
+  });
+
+  const createMut = useMutation({
+    mutationFn: createGeneralSkill,
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ["admin-skills"] });
+      setCreating(false);
+    },
+  });
+
+  const updateMut = useMutation({
+    mutationFn: ({ id, ...data }: { id: string } & Record<string, string>) =>
+      updateGeneralSkill(id, data),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ["admin-skills"] });
+      setEditing(null);
+    },
+  });
+
+  const deleteMut = useMutation({
+    mutationFn: deleteGeneralSkill,
+    onSuccess: () => queryClient.invalidateQueries({ queryKey: ["admin-skills"] }),
+  });
+
+  if (creating || editing) {
+    return (
+      <div className="max-w-2xl space-y-4">
+        <h1 className="text-2xl font-semibold">
+          {creating ? t("skills.create_general") : t("skills.edit_general")}
+        </h1>
+        <SkillEditor
+          skill={editing}
+          onSave={(data) =>
+            editing
+              ? updateMut.mutate({ id: editing.id, ...data })
+              : createMut.mutate(data)
+          }
+          onCancel={() => { setCreating(false); setEditing(null); }}
+          loading={createMut.isPending || updateMut.isPending}
+        />
+      </div>
+    );
+  }
+
+  return (
+    <div className="space-y-4">
+      <div className="flex items-center justify-between">
+        <h1 className="text-2xl font-semibold">{t("skills.general_skills")}</h1>
+        <button
+          onClick={() => setCreating(true)}
+          className="inline-flex h-9 items-center gap-2 rounded-md bg-primary px-4 text-sm font-medium text-primary-foreground hover:bg-primary/90 transition-colors"
+        >
+          <Plus className="h-4 w-4" /> {t("common.create")}
+        </button>
+      </div>
+
+      {skills.length === 0 && (
+        <p className="text-muted-foreground py-8 text-center">{t("skills.no_skills")}</p>
+      )}
+
+      <div className="space-y-2">
+        {skills.map((skill) => (
+          <div key={skill.id} className="flex items-center gap-3 rounded-lg border bg-card p-4">
+            <Sparkles className="h-5 w-5 text-primary shrink-0" />
+            <div className="flex-1 min-w-0">
+              <p className="font-medium">{skill.name}</p>
+              {skill.description && (
+                <p className="text-sm text-muted-foreground truncate">{skill.description}</p>
+              )}
+            </div>
+            <div className="flex gap-1">
+              <button onClick={() => setEditing(skill)} className="rounded p-2 hover:bg-accent transition-colors">
+                <Pencil className="h-4 w-4" />
+              </button>
+              <button
+                onClick={() => deleteMut.mutate(skill.id)}
+                className="rounded p-2 hover:bg-destructive/10 hover:text-destructive transition-colors"
+              >
+                <Trash2 className="h-4 w-4" />
+              </button>
+            </div>
+          </div>
+        ))}
+      </div>
+    </div>
+  );
+}
--- a/frontend/src/pages/chat.tsx
+++ b/frontend/src/pages/chat.tsx
@@ -1,20 +1,34 @@
 import { useEffect } from "react";
 import { useParams, useNavigate } from "react-router-dom";
+import { useMutation, useQueryClient } from "@tanstack/react-query";
 import { ChatList } from "@/components/chat/chat-list";
 import { ChatWindow } from "@/components/chat/chat-window";
 import { useChatStore } from "@/stores/chat-store";
 import { useChat } from "@/hooks/use-chat";
+import { updateChat } from "@/api/chats";

 export function ChatPage() {
  const { chatId } = useParams();
  const navigate = useNavigate();
-  const setCurrentChat = useChatStore((s) => s.setCurrentChat);
+  const queryClient = useQueryClient();
+  const { currentChatId, chats, setCurrentChat, updateChatInList } = useChatStore();
  const { createChat, deleteChat, archiveChat, sendMessage, limitReached } = useChat();

  useEffect(() => {
    setCurrentChat(chatId || null);
  }, [chatId, setCurrentChat]);

+  const currentChat = chats.find((c) => c.id === currentChatId);
+
+  const skillMutation = useMutation({
+    mutationFn: ({ chatId, skillId }: { chatId: string; skillId: string | null }) =>
+      updateChat(chatId, { skill_id: skillId || undefined }),
+    onSuccess: (chat) => {
+      updateChatInList(chat);
+      queryClient.invalidateQueries({ queryKey: ["chats"] });
+    },
+  });
+
  const handleCreateChat = async () => {
    const chat = await createChat(undefined);
    navigate(`/chat/${chat.id}`);
@@ -25,6 +39,12 @@ export function ChatPage() {
    if (chatId === id) navigate("/chat");
  };

+  const handleChangeSkill = (skillId: string | null) => {
+    if (currentChatId) {
+      skillMutation.mutate({ chatId: currentChatId, skillId });
+    }
+  };
+
  return (
    <div className="flex h-full -m-6">
      <div className="w-64 shrink-0 border-r bg-card">
@@ -36,7 +56,11 @@ export function ChatPage() {
        />
      </div>
      <div className="flex-1">
-        <ChatWindow onSendMessage={sendMessage} />
+        <ChatWindow
+          onSendMessage={sendMessage}
+          onChangeSkill={handleChangeSkill}
+          currentSkillId={currentChat?.skill_id}
+        />
      </div>
    </div>
  );
--- a/frontend/src/pages/profile/context.tsx
+++ b/frontend/src/pages/profile/context.tsx
@@ -0,0 +1,76 @@
+import { useState, useEffect } from "react";
+import { useTranslation } from "react-i18next";
+import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
+import { getPersonalContext, updatePersonalContext } from "@/api/user-context";
+import { Save } from "lucide-react";
+
+export function PersonalContextPage() {
+  const { t } = useTranslation();
+  const queryClient = useQueryClient();
+  const [content, setContent] = useState("");
+  const [hasChanges, setHasChanges] = useState(false);
+
+  const query = useQuery({
+    queryKey: ["personal-context"],
+    queryFn: getPersonalContext,
+  });
+
+  useEffect(() => {
+    if (query.data) {
+      setContent(query.data.content);
+      setHasChanges(false);
+    }
+  }, [query.data]);
+
+  const mutation = useMutation({
+    mutationFn: (text: string) => updatePersonalContext(text),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ["personal-context"] });
+      setHasChanges(false);
+    },
+  });
+
+  useEffect(() => {
+    const handler = (e: BeforeUnloadEvent) => {
+      if (hasChanges) e.preventDefault();
+    };
+    window.addEventListener("beforeunload", handler);
+    return () => window.removeEventListener("beforeunload", handler);
+  }, [hasChanges]);
+
+  return (
+    <div className="space-y-4">
+      <div className="flex items-center justify-between">
+        <div>
+          <h1 className="text-2xl font-semibold tracking-tight">
+            {t("personal_context.title")}
+          </h1>
+          <p className="text-sm text-muted-foreground">
+            {t("personal_context.subtitle")}
+          </p>
+        </div>
+        <div className="flex items-center gap-2">
+          {hasChanges && (
+            <span className="text-sm text-amber-500">{t("admin.unsaved_changes")}</span>
+          )}
+          <button
+            onClick={() => mutation.mutate(content)}
+            disabled={!hasChanges || mutation.isPending}
+            className="inline-flex h-9 items-center gap-2 rounded-md bg-primary px-4 text-sm font-medium text-primary-foreground hover:bg-primary/90 disabled:opacity-50 transition-colors"
+          >
+            <Save className="h-4 w-4" />
+            {mutation.isPending ? t("common.loading") : t("common.save")}
+          </button>
+        </div>
+      </div>
+
+      <textarea
+        value={content}
+        onChange={(e) => { setContent(e.target.value); setHasChanges(true); }}
+        rows={15}
+        className="w-full resize-y rounded-lg border border-input bg-background px-4 py-3 text-sm font-mono ring-offset-background placeholder:text-muted-foreground focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
+        placeholder={t("personal_context.placeholder")}
+      />
+    </div>
+  );
+}
--- a/frontend/src/pages/skills.tsx
+++ b/frontend/src/pages/skills.tsx
@@ -0,0 +1,108 @@
+import { useState } from "react";
+import { useTranslation } from "react-i18next";
+import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
+import { getSkills, createSkill, updateSkill, deleteSkill, type Skill } from "@/api/skills";
+import { SkillEditor } from "@/components/admin/skill-editor";
+import { Plus, Pencil, Trash2, Sparkles } from "lucide-react";
+
+export function SkillsPage() {
+  const { t } = useTranslation();
+  const queryClient = useQueryClient();
+  const [editing, setEditing] = useState<Skill | null>(null);
+  const [creating, setCreating] = useState(false);
+
+  const { data: skills = [] } = useQuery({
+    queryKey: ["personal-skills"],
+    queryFn: () => getSkills(false),
+  });
+
+  const createMut = useMutation({
+    mutationFn: createSkill,
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ["personal-skills"] });
+      queryClient.invalidateQueries({ queryKey: ["skills"] });
+      setCreating(false);
+    },
+  });
+
+  const updateMut = useMutation({
+    mutationFn: ({ id, ...data }: { id: string } & Record<string, string>) =>
+      updateSkill(id, data),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ["personal-skills"] });
+      queryClient.invalidateQueries({ queryKey: ["skills"] });
+      setEditing(null);
+    },
+  });
+
+  const deleteMut = useMutation({
+    mutationFn: deleteSkill,
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ["personal-skills"] });
+      queryClient.invalidateQueries({ queryKey: ["skills"] });
+    },
+  });
+
+  if (creating || editing) {
+    return (
+      <div className="max-w-2xl space-y-4">
+        <h1 className="text-2xl font-semibold">
+          {creating ? t("skills.create_personal") : t("skills.edit_personal")}
+        </h1>
+        <SkillEditor
+          skill={editing}
+          onSave={(data) =>
+            editing
+              ? updateMut.mutate({ id: editing.id, ...data })
+              : createMut.mutate(data)
+          }
+          onCancel={() => { setCreating(false); setEditing(null); }}
+          loading={createMut.isPending || updateMut.isPending}
+        />
+      </div>
+    );
+  }
+
+  return (
+    <div className="space-y-4">
+      <div className="flex items-center justify-between">
+        <h1 className="text-2xl font-semibold">{t("skills.my_skills")}</h1>
+        <button
+          onClick={() => setCreating(true)}
+          className="inline-flex h-9 items-center gap-2 rounded-md bg-primary px-4 text-sm font-medium text-primary-foreground hover:bg-primary/90 transition-colors"
+        >
+          <Plus className="h-4 w-4" /> {t("common.create")}
+        </button>
+      </div>
+
+      {skills.length === 0 && (
+        <p className="text-muted-foreground py-8 text-center">{t("skills.no_personal_skills")}</p>
+      )}
+
+      <div className="space-y-2">
+        {skills.map((skill) => (
+          <div key={skill.id} className="flex items-center gap-3 rounded-lg border bg-card p-4">
+            <Sparkles className="h-5 w-5 text-primary shrink-0" />
+            <div className="flex-1 min-w-0">
+              <p className="font-medium">{skill.name}</p>
+              {skill.description && (
+                <p className="text-sm text-muted-foreground truncate">{skill.description}</p>
+              )}
+            </div>
+            <div className="flex gap-1">
+              <button onClick={() => setEditing(skill)} className="rounded p-2 hover:bg-accent transition-colors">
+                <Pencil className="h-4 w-4" />
+              </button>
+              <button
+                onClick={() => deleteMut.mutate(skill.id)}
+                className="rounded p-2 hover:bg-destructive/10 hover:text-destructive transition-colors"
+              >
+                <Trash2 className="h-4 w-4" />
+              </button>
+            </div>
+          </div>
+        ))}
+      </div>
+    </div>
+  );
+}
--- a/frontend/src/routes.tsx
+++ b/frontend/src/routes.tsx
@@ -5,7 +5,10 @@ import { LoginPage } from "@/pages/login";
 import { RegisterPage } from "@/pages/register";
 import { DashboardPage } from "@/pages/dashboard";
 import { ChatPage } from "@/pages/chat";
+import { SkillsPage } from "@/pages/skills";
+import { PersonalContextPage } from "@/pages/profile/context";
 import { AdminContextPage } from "@/pages/admin/context";
+import { AdminSkillsPage } from "@/pages/admin/skills";
 import { NotFoundPage } from "@/pages/not-found";

 export const router = createBrowserRouter([
@@ -26,7 +29,10 @@ export const router = createBrowserRouter([
          { index: true, element: <DashboardPage /> },
          { path: "chat", element: <ChatPage /> },
          { path: "chat/:chatId", element: <ChatPage /> },
+          { path: "skills", element: <SkillsPage /> },
+          { path: "profile/context", element: <PersonalContextPage /> },
          { path: "admin/context", element: <AdminContextPage /> },
+          { path: "admin/skills", element: <AdminSkillsPage /> },
        ],
      },
    ],
--- a/plans/phase-3-skills-context.md
+++ b/plans/phase-3-skills-context.md
@@ -0,0 +1,109 @@
+# Phase 3: Skills & Context — Subplan
+
+## Goal
+
+Deliver a skill system (general + personal) with CRUD, a personal context editor per user, and context assembly that layers personal context and skill prompts into AI conversations, with frontend management pages and a skill selector in chat.
+
+## Prerequisites
+
+- Phase 2 completed: chat CRUD, SSE streaming, Claude API integration, context assembly, admin context editor
+- `context_files` table already exists (Phase 2 migration)
+- `chats.skill_id` column already exists (nullable, Phase 2)
+
+---
+
+## Database Schema (Phase 3)
+
+### `skills` table (new)
+
+| Column | Type | Constraints |
+|---|---|---|
+| id | UUID | PK (inherited from Base) |
+| user_id | UUID | FK -> users.id ON DELETE CASCADE, NULL = general skill |
+| name | VARCHAR(100) | NOT NULL |
+| description | TEXT | NULL |
+| system_prompt | TEXT | NOT NULL |
+| icon | VARCHAR(50) | NULL (Lucide icon name) |
+| is_active | BOOLEAN | NOT NULL, default true |
+| sort_order | INTEGER | NOT NULL, default 0 |
+| created_at | TIMESTAMPTZ | inherited from Base |
+
+Also: add FK constraint `chats.skill_id` -> `skills.id ON DELETE SET NULL`.
+
+---
+
+## Tasks
+
+### A. Backend Model & Migration (Tasks 1–3)
+
+- [x] **A1.** Create `backend/app/models/skill.py`. Add `skills` relationship on User model. Add `skill` relationship on Chat model.
+- [x] **A2.** Update `backend/app/models/__init__.py`: import Skill.
+- [x] **A3.** Create migration `003_create_skills_add_chat_skill_fk.py`.
+
+### B. Backend Schemas (Task 4)
+
+- [x] **B4.** Create `backend/app/schemas/skill.py`. Extend `CreateChatRequest`/`UpdateChatRequest` with optional `skill_id`.
+
+### C. Backend Services (Tasks 5–7)
+
+- [x] **C5.** Create `backend/app/services/skill_service.py`: CRUD for personal + general skills with access checks.
+- [x] **C6.** Extend `context_service.py`: add `get_personal_context`, `upsert_personal_context`.
+- [x] **C7.** Extend `ai_service.py` `assemble_context`: add personal context (step 2) + skill prompt (step 3).
+
+### D. Backend API Endpoints (Tasks 8–11)
+
+- [x] **D8.** Create `backend/app/api/v1/skills.py`: personal skills CRUD.
+- [x] **D9.** Extend `backend/app/api/v1/admin.py`: admin skills CRUD under `/admin/skills/`.
+- [x] **D10.** Create `backend/app/api/v1/users.py`: `GET/PUT /users/me/context`.
+- [x] **D11.** Update router, chats endpoints (skill_id validation on create/update).
+
+### E. Frontend API (Tasks 12–13)
+
+- [x] **E12.** Create `frontend/src/api/skills.ts` + extend `admin.ts` with admin skill functions.
+- [x] **E13.** Create `frontend/src/api/user-context.ts`.
+
+### F. Frontend Skill Selector (Tasks 14–15)
+
+- [x] **F14.** Create `frontend/src/components/chat/skill-selector.tsx`.
+- [x] **F15.** Update chat creation + chat window to support skill_id.
+
+### G. Frontend Admin Skills (Tasks 16–17)
+
+- [x] **G16.** Create `frontend/src/components/admin/skill-editor.tsx` (reusable form).
+- [x] **G17.** Create `frontend/src/pages/admin/skills.tsx`.
+
+### H. Frontend Personal Skills & Context (Tasks 18–19)
+
+- [x] **H18.** Create `frontend/src/pages/skills.tsx`.
+- [x] **H19.** Create `frontend/src/pages/profile/context.tsx`.
+
+### I. Routing, Sidebar, i18n (Tasks 20–22)
+
+- [x] **I20.** Update routes: `/skills`, `/profile/context`, `/admin/skills`.
+- [x] **I21.** Update sidebar: add Skills nav, admin skills link.
+- [x] **I22.** Update en/ru translations.
+
+### J. Backend Tests (Task 23)
+
+- [x] **J23.** Create `backend/tests/test_skills.py`.
+
+---
+
+## Acceptance Criteria
+
+1. Migration creates `skills` table and adds FK on `chats.skill_id`
+2. Admin can CRUD general skills; users cannot
+3. Users can CRUD own personal skills; isolated from other users
+4. Users can read/write personal context via `/users/me/context`
+5. Context assembly: primary context + personal context + skill prompt
+6. Chat creation/update accepts `skill_id`, validates accessibility
+7. Skill selector dropdown in chat creation and header
+8. Admin skills page, personal skills page, personal context editor
+9. All UI text in English and Russian
+10. Backend tests pass
+
+---
+
+## Status
+
+**COMPLETED**