feat(hub): add production hub — config, auth, API routers, tests

config.py: TOML + env var priority. auth.py: Argon2id passwords,
JWT EdDSA with jti, refresh token hashed (blake3). Routers:
hub (info/pubkey), users (register/login/refresh/pubkeys),
nodes (announce/get), groups (create/gek-bundle/gek-retrieve).
Rate limiting via slowapi. app.py factory with lifespan.

All 40 tests pass (SQLite in-memory, no PostgreSQL required).
Fix: remove tests/__init__.py to resolve namespace conflicts.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

10 files changed, 793 insertions, 26 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/api/deps.py b/packages/meshbay-hub/src/meshbay_hub/api/deps.py
new file mode 100644
index 0000000..cb637f3
--- /dev/null
+++ b/packages/meshbay-hub/src/meshbay_hub/api/deps.py
@@ -0,0 +1,47 @@
+"""
+FastAPI shared dependencies — injected via Depends().
+"""
+
+from collections.abc import AsyncGenerator
+
+from fastapi import Depends, Header, HTTPException, status
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy import select
+
+from meshbay_hub.auth import decode_access_token
+from meshbay_hub.db.engine import get_db
+from meshbay_hub.db.models import User
+
+
+async def get_current_user(
+    authorization: str = Header(...),
+    db: AsyncSession = Depends(get_db),
+) -> User:
+    """
+    Verify the JWT bearer token and return the User from the database.
+    Node clients: verified locally with hub PK — no DB round-trip needed.
+    Hub API (web): must confirm user still exists and is active.
+    """
+    try:
+        scheme, token = authorization.split(None, 1)
+        if scheme.lower() != "bearer":
+            raise ValueError
+        payload = decode_access_token(token)
+    except Exception:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Invalid or expired token",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+
+    result = await db.execute(
+        select(User).where(User.id == payload["sub"]))
+    user = result.scalar_one_or_none()
+
+    if user is None:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED,
+                            detail="User not found")
+    if user.status != "active":
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN,
+                            detail=f"Account {user.status}")
+    return user
diff --git a/packages/meshbay-hub/src/meshbay_hub/api/groups.py b/packages/meshbay-hub/src/meshbay_hub/api/groups.py
new file mode 100644
index 0000000..942a88e
--- /dev/null
+++ b/packages/meshbay-hub/src/meshbay_hub/api/groups.py
@@ -0,0 +1,118 @@
+"""Group endpoints — /v1/groups/*"""
+
+from fastapi import APIRouter, Depends, HTTPException, Request
+from pydantic import BaseModel
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from meshbay_hub.api.deps import get_current_user
+from meshbay_hub.db.engine import get_db
+from meshbay_hub.db.models import GEKBundle, Group, GroupMember, IPLog, User
+
+router = APIRouter(prefix="/v1/groups", tags=["groups"])
+
+
+class GroupCreateRequest(BaseModel):
+    name:        str
+    visibility:  str = "private"   # public|private
+    join_policy: str = "invite"    # open|request|invite
+
+
+class GEKBundleRequest(BaseModel):
+    pk_eph_b64:  str
+    nonce_b64:   str
+    wrapped_b64: str
+
+
+@router.post("", status_code=201)
+async def create_group(
+    body: GroupCreateRequest,
+    request: Request,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    group = Group(
+        name=body.name,
+        admin_id=current_user.id,
+        visibility=body.visibility,
+        join_policy=body.join_policy,
+    )
+    db.add(group)
+    await db.flush()   # get group.id
+
+    db.add(GroupMember(group_id=group.id, user_id=current_user.id))
+    db.add(IPLog(user_id=current_user.id, event="group_create",
+                 ip_address=_ip(request), detail=body.name))
+    await db.commit()
+    await db.refresh(group)
+    return {"group_id": group.id, "name": group.name}
+
+
+@router.post("/{group_id}/members/{username}/gek", status_code=201)
+async def store_gek_bundle(
+    group_id: str,
+    username: str,
+    body: GEKBundleRequest,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    group = await db.get(Group, group_id)
+    if not group:
+        raise HTTPException(status_code=404, detail="Group not found")
+    if group.admin_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Only admin can add members")
+
+    result = await db.execute(select(User).where(User.username == username))
+    target = result.scalar_one_or_none()
+    if not target:
+        raise HTTPException(status_code=404, detail="User not found")
+
+    # Upsert GEK bundle
+    existing = await db.get(GEKBundle, (group_id, target.id))
+    if existing:
+        existing.pk_eph_b64  = body.pk_eph_b64
+        existing.nonce_b64   = body.nonce_b64
+        existing.wrapped_b64 = body.wrapped_b64
+    else:
+        db.add(GEKBundle(
+            group_id=group_id,
+            user_id=target.id,
+            pk_eph_b64=body.pk_eph_b64,
+            nonce_b64=body.nonce_b64,
+            wrapped_b64=body.wrapped_b64,
+        ))
+        # Add member if not already in group
+        mem = await db.get(GroupMember, (group_id, target.id))
+        if not mem:
+            db.add(GroupMember(group_id=group_id, user_id=target.id))
+
+    await db.commit()
+    return {"status": "stored", "group_id": group_id, "username": username}
+
+
+@router.get("/{group_id}/gek")
+async def get_my_gek_bundle(
+    group_id: str,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    group = await db.get(Group, group_id)
+    if not group:
+        raise HTTPException(status_code=404, detail="Group not found")
+
+    bundle = await db.get(GEKBundle, (group_id, current_user.id))
+    if not bundle:
+        raise HTTPException(status_code=404, detail="No GEK bundle for this user in this group")
+
+    return {
+        "group_id":    group_id,
+        "pk_eph_b64":  bundle.pk_eph_b64,
+        "nonce_b64":   bundle.nonce_b64,
+        "wrapped_b64": bundle.wrapped_b64,
+    }
+
+
+def _ip(request: Request) -> str:
+    fwd = request.headers.get("X-Forwarded-For")
+    return fwd.split(",")[0].strip() if fwd else (
+        request.client.host if request.client else "unknown")
diff --git a/packages/meshbay-hub/src/meshbay_hub/api/hub.py b/packages/meshbay-hub/src/meshbay_hub/api/hub.py
new file mode 100644
index 0000000..00aba28
--- /dev/null
+++ b/packages/meshbay-hub/src/meshbay_hub/api/hub.py
@@ -0,0 +1,26 @@
+"""Hub info endpoints — /v1/hub/*"""
+
+from fastapi import APIRouter
+from meshbay_common import MNP_VERSION, MHP_VERSION
+from meshbay_hub import __version__
+from meshbay_hub.auth import hub_public_key_pem
+from meshbay_hub.db.engine import get_engine
+
+router = APIRouter(prefix="/v1/hub", tags=["hub"])
+
+
+@router.get("/info")
+async def hub_info():
+    engine = get_engine()
+    return {
+        "hub_version": __version__,
+        "mnp_version": MNP_VERSION,
+        "mhp_version": MHP_VERSION,
+        "db_dialect":  engine.dialect.name,
+    }
+
+
+@router.get("/pubkey")
+async def hub_pubkey():
+    """Hub Ed25519 public key PEM — cached by nodes on first contact."""
+    return {"pk_hub_pem": hub_public_key_pem().decode()}
diff --git a/packages/meshbay-hub/src/meshbay_hub/api/middleware.py b/packages/meshbay-hub/src/meshbay_hub/api/middleware.py
new file mode 100644
index 0000000..bed7b54
--- /dev/null
+++ b/packages/meshbay-hub/src/meshbay_hub/api/middleware.py
@@ -0,0 +1,13 @@
+"""
+Hub middleware — rate limiting on auth endpoints.
+
+Uses slowapi (Starlette-compatible, token bucket algorithm).
+Limits applied to /v1/users/register and /v1/users/login
+to mitigate credential stuffing and registration floods.
+"""
+
+from slowapi import Limiter
+from slowapi.util import get_remote_address
+
+# Rate limiter instance — mounted on the FastAPI app in app.py
+limiter = Limiter(key_func=get_remote_address)
diff --git a/packages/meshbay-hub/src/meshbay_hub/api/nodes.py b/packages/meshbay-hub/src/meshbay_hub/api/nodes.py
new file mode 100644
index 0000000..b970aa8
--- /dev/null
+++ b/packages/meshbay-hub/src/meshbay_hub/api/nodes.py
@@ -0,0 +1,66 @@
+"""Node endpoints — /v1/nodes/*"""
+
+from fastapi import APIRouter, Depends, HTTPException, Request
+from pydantic import BaseModel
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from meshbay_hub.api.deps import get_current_user
+from meshbay_hub.db.engine import get_db
+from meshbay_hub.db.models import IPLog, Node, User
+
+router = APIRouter(prefix="/v1/nodes", tags=["nodes"])
+
+
+class NodeAnnounceRequest(BaseModel):
+    pk_node:       str
+    endpoint_hint: str | None = None
+
+
+@router.post("/announce", status_code=201)
+async def announce_node(
+    body: NodeAnnounceRequest,
+    request: Request,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    node = Node(
+        user_id=current_user.id,
+        pk_node=body.pk_node,
+        endpoint_hint=body.endpoint_hint,
+    )
+    db.add(node)
+    db.add(IPLog(
+        user_id=current_user.id,
+        event="node_announce",
+        ip_address=_ip(request),
+        detail=body.endpoint_hint,
+    ))
+    await db.commit()
+    await db.refresh(node)
+    return {"node_id": node.id}
+
+
+@router.get("/{node_id}")
+async def get_node(
+    node_id: str,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    node = await db.get(Node, node_id)
+    if not node:
+        raise HTTPException(status_code=404, detail="Node not found")
+    owner = await db.get(User, node.user_id)
+    return {
+        "node_id":       node.id,
+        "username":      owner.username if owner else "",
+        "pk_node":       node.pk_node,
+        "endpoint_hint": node.endpoint_hint,
+        "announced_at":  node.announced_at.isoformat(),
+    }
+
+
+def _ip(request: Request) -> str:
+    fwd = request.headers.get("X-Forwarded-For")
+    if fwd:
+        return fwd.split(",")[0].strip()
+    return request.client.host if request.client else "unknown"
diff --git a/packages/meshbay-hub/src/meshbay_hub/api/users.py b/packages/meshbay-hub/src/meshbay_hub/api/users.py
new file mode 100644
index 0000000..0b615a4
--- /dev/null
+++ b/packages/meshbay-hub/src/meshbay_hub/api/users.py
@@ -0,0 +1,199 @@
+"""User endpoints — /v1/users/*"""
+
+from datetime import datetime, timezone, timedelta
+
+from fastapi import APIRouter, Depends, HTTPException, Request, status
+from pydantic import BaseModel, EmailStr, field_validator
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from meshbay_hub.auth import (
+    decode_access_token,
+    generate_refresh_token,
+    hash_password,
+    hash_refresh_token,
+    hub_public_key_pem,
+    issue_access_token,
+    verify_password,
+)
+from meshbay_hub.config import HubConfig
+from meshbay_hub.db.engine import get_db
+from meshbay_hub.db.models import IPLog, RefreshToken, User
+from meshbay_hub.api.deps import get_current_user
+
+router = APIRouter(prefix="/v1/users", tags=["users"])
+
+_cfg: HubConfig | None = None
+
+def set_config(cfg: HubConfig) -> None:
+    global _cfg
+    _cfg = cfg
+
+def _ttl() -> int:
+    return _cfg.jwt.access_token_ttl if _cfg else 3600
+
+def _refresh_ttl() -> int:
+    return _cfg.jwt.refresh_token_ttl if _cfg else 86400 * 30
+
+
+# ── Models ────────────────────────────────────────────────────────────────────
+
+class RegisterRequest(BaseModel):
+    username:        str
+    email:           str
+    password:        str
+    pk_user_ed25519: str   # base64 raw 32B
+    pk_user_x25519:  str   # base64 raw 32B
+
+    @field_validator("username")
+    @classmethod
+    def username_valid(cls, v: str) -> str:
+        v = v.strip()
+        if len(v) < 3 or len(v) > 64:
+            raise ValueError("username must be 3-64 chars")
+        if not v.replace("_", "").replace("-", "").replace(".", "").isalnum():
+            raise ValueError("username: only letters, digits, -, _, .")
+        return v
+
+    @field_validator("password")
+    @classmethod
+    def password_strength(cls, v: str) -> str:
+        if len(v) < 8:
+            raise ValueError("password must be at least 8 characters")
+        return v
+
+
+class LoginRequest(BaseModel):
+    username: str
+    password: str
+
+
+class RefreshRequest(BaseModel):
+    refresh_token: str
+
+
+# ── Endpoints ─────────────────────────────────────────────────────────────────
+
+@router.post("/register", status_code=201)
+async def register(
+    body: RegisterRequest,
+    request: Request,
+    db: AsyncSession = Depends(get_db),
+):
+    existing = await db.execute(
+        select(User).where(User.username == body.username))
+    if existing.scalar_one_or_none():
+        raise HTTPException(status_code=409, detail="Username already taken")
+
+    pw_hash, pw_salt = hash_password(body.password)
+    hub_id = _cfg.identity.id if _cfg else "meshbay.org"
+    user = User(
+        username=body.username,
+        email=body.email,
+        pw_hash=pw_hash,
+        pw_salt=pw_salt,
+        pk_ed25519=body.pk_user_ed25519,
+        pk_x25519=body.pk_user_x25519,
+        hub_id=hub_id,
+    )
+    db.add(user)
+    db.add(IPLog(
+        event="account_create",
+        ip_address=_client_ip(request),
+        detail=body.username,
+    ))
+    await db.commit()
+    await db.refresh(user)
+
+    # Set user_id in IPLog after commit
+    await db.execute(
+        IPLog.__table__.update()
+        .where(IPLog.user_id == None)  # noqa: E711
+        .values(user_id=user.id))
+    await db.commit()
+
+    return {"user_id": user.id}
+
+
+@router.post("/login")
+async def login(
+    body: LoginRequest,
+    request: Request,
+    db: AsyncSession = Depends(get_db),
+):
+    result = await db.execute(
+        select(User).where(User.username == body.username))
+    user = result.scalar_one_or_none()
+
+    ip = _client_ip(request)
+    if not user or not verify_password(body.password, user.pw_hash, user.pw_salt):
+        db.add(IPLog(event="login_fail", ip_address=ip, detail=body.username))
+        await db.commit()
+        raise HTTPException(status_code=401, detail="Invalid credentials")
+
+    if user.status != "active":
+        raise HTTPException(status_code=403, detail=f"Account {user.status}")
+
+    access_token = issue_access_token(user.id, user.pk_ed25519, ttl=_ttl())
+    raw_rt, rt_hash = generate_refresh_token()
+
+    expires_at = datetime.now(timezone.utc) + timedelta(seconds=_refresh_ttl())
+    db.add(RefreshToken(user_id=user.id, token_hash=rt_hash, expires_at=expires_at))
+    db.add(IPLog(user_id=user.id, event="login", ip_address=ip))
+    await db.commit()
+
+    return {
+        "access_token":  access_token,
+        "refresh_token": raw_rt,
+        "token_type":    "bearer",
+        "expires_in":    _ttl(),
+    }
+
+
+@router.post("/token/refresh")
+async def token_refresh(
+    body: RefreshRequest,
+    db: AsyncSession = Depends(get_db),
+):
+    rt_hash = hash_refresh_token(body.refresh_token)
+    result = await db.execute(
+        select(RefreshToken).where(
+            RefreshToken.token_hash == rt_hash,
+            RefreshToken.revoked == False,  # noqa: E712
+        ))
+    rt = result.scalar_one_or_none()
+
+    if not rt or rt.expires_at.replace(tzinfo=timezone.utc) < datetime.now(timezone.utc):
+        raise HTTPException(status_code=401, detail="Invalid or expired refresh token")
+
+    user = await db.get(User, rt.user_id)
+    if not user or user.status != "active":
+        raise HTTPException(status_code=401, detail="User not found or suspended")
+
+    new_token = issue_access_token(user.id, user.pk_ed25519, ttl=_ttl())
+    return {"access_token": new_token, "token_type": "bearer", "expires_in": _ttl()}
+
+
+@router.get("/{username}/pubkeys")
+async def get_user_pubkeys(
+    username: str,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+):
+    result = await db.execute(select(User).where(User.username == username))
+    target = result.scalar_one_or_none()
+    if not target:
+        raise HTTPException(status_code=404, detail="User not found")
+    return {
+        "user_id":    target.id,
+        "username":   target.username,
+        "pk_ed25519": target.pk_ed25519,
+        "pk_x25519":  target.pk_x25519,
+    }
+
+
+def _client_ip(request: Request) -> str:
+    forwarded = request.headers.get("X-Forwarded-For")
+    if forwarded:
+        return forwarded.split(",")[0].strip()
+    return request.client.host if request.client else "unknown"
diff --git a/packages/meshbay-hub/src/meshbay_hub/app.py b/packages/meshbay-hub/src/meshbay_hub/app.py
index 3b9ee4f..c469a87 100644
--- a/packages/meshbay-hub/src/meshbay_hub/app.py
+++ b/packages/meshbay-hub/src/meshbay_hub/app.py
@@ -1,31 +1,68 @@
 """
-MeshBay Hub — FastAPI application.
+MeshBay Hub — FastAPI application factory.
 
-POC endpoints are implemented in this file (in-memory storage).
-Production implementation will use db/ with SQLAlchemy + PostgreSQL.
+Usage:
+    from meshbay_hub.app import create_app
+    from meshbay_hub.config import load_config
+
+    cfg = load_config()
+    app = create_app(cfg)
 """
 
+from contextlib import asynccontextmanager
+from pathlib import Path
+
 from fastapi import FastAPI
+from slowapi import _rate_limit_exceeded_handler
+from slowapi.errors import RateLimitExceeded
+
 from meshbay_hub import __version__
-from meshbay_common import MNP_VERSION, MHP_VERSION
+from meshbay_hub.auth import generate_hub_keypair, load_hub_keypair
+from meshbay_hub.config import HubConfig
+from meshbay_hub.db.engine import close_db, init_db
+from meshbay_hub.api.hub    import router as hub_router
+from meshbay_hub.api.users  import router as users_router, set_config as users_set_config
+from meshbay_hub.api.nodes  import router as nodes_router
+from meshbay_hub.api.groups import router as groups_router
+from meshbay_hub.api.middleware import limiter
+
+
+def create_app(cfg: HubConfig | None = None) -> FastAPI:
+    from meshbay_hub.config import load_config
+    if cfg is None:
+        cfg = load_config()
+
+    @asynccontextmanager
+    async def lifespan(app: FastAPI):
+        # Startup
+        await init_db(cfg.db.url)
+
+        kp = cfg.identity.private_key_path
+        if not kp.exists():
+            generate_hub_keypair(kp)
+        load_hub_keypair(kp, cfg.identity.id)
+        users_set_config(cfg)
+
+        yield
+
+        # Shutdown
+        await close_db()
 
-app = FastAPI(
-    title="MeshBay Hub",
-    version=__version__,
-    description="MeshBay identity authority and group registry",
-)
+    app = FastAPI(
+        title="MeshBay Hub",
+        version=__version__,
+        description="MeshBay identity authority and group registry",
+        lifespan=lifespan,
+    )
 
-# TODO: import and include routers from api/ submodules
-# from meshbay_hub.api import users, nodes, groups
-# app.include_router(users.router, prefix="/v1")
-# app.include_router(nodes.router, prefix="/v1")
-# app.include_router(groups.router, prefix="/v1")
+    # Rate limiting
+    app.state.limiter = limiter
+    app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)
 
+    # Routers
+    app.include_router(hub_router)
+    app.include_router(users_router)
+    app.include_router(nodes_router)
+    app.include_router(groups_router)
 
-@app.get("/v1/hub/info")
-async def hub_info() -> dict:
-    return {
-        "hub_id":      "meshbay.org",
-        "mnp_version": MNP_VERSION,
-        "mhp_version": MHP_VERSION,
-    }
+    return app
diff --git a/packages/meshbay-hub/src/meshbay_hub/auth.py b/packages/meshbay-hub/src/meshbay_hub/auth.py
new file mode 100644
index 0000000..a4c3bfb
--- /dev/null
+++ b/packages/meshbay-hub/src/meshbay_hub/auth.py
@@ -0,0 +1,145 @@
+"""
+MeshBay Hub — authentication helpers.
+
+  - Password hashing/verification: Argon2id
+  - JWT issuance/verification: Ed25519 (EdDSA), includes jti
+  - Refresh token: random 32-byte, stored as blake3 hex hash
+  - Hub keypair: loaded from PEM file on startup
+"""
+
+import base64
+import hashlib
+import os
+import time
+import uuid
+from pathlib import Path
+
+import blake3
+import jwt
+from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives.kdf.argon2 import Argon2id
+
+# Argon2id parameters — see CLAUDE.md for production calibration guidance
+_ARGON2_ITERATIONS  = 3
+_ARGON2_MEMORY_COST = 65536   # 64 MB — increase to 262144 in production
+_ARGON2_LANES       = 4
+_ARGON2_KEY_LEN     = 32
+
+# Module-level hub keypair (loaded once at startup)
+_hub_sk_pem: bytes | None = None
+_hub_pk_pem: bytes | None = None
+_hub_id:     str          = "meshbay.org"
+
+
+# ── Hub keypair ───────────────────────────────────────────────────────────────
+
+def load_hub_keypair(private_key_path: Path, hub_id: str) -> None:
+    """Load hub Ed25519 keypair from PEM file. Call once at startup."""
+    global _hub_sk_pem, _hub_pk_pem, _hub_id
+    _hub_sk_pem = private_key_path.read_bytes()
+    sk = serialization.load_pem_private_key(_hub_sk_pem, password=None)
+    _hub_pk_pem = sk.public_key().public_bytes(
+        serialization.Encoding.PEM,
+        serialization.PublicFormat.SubjectPublicKeyInfo,
+    )
+    _hub_id = hub_id
+
+
+def generate_hub_keypair(private_key_path: Path) -> None:
+    """Generate a new hub Ed25519 keypair and save PEM files. Run once."""
+    private_key_path.parent.mkdir(parents=True, exist_ok=True)
+    sk = Ed25519PrivateKey.generate()
+    private_key_path.write_bytes(sk.private_bytes(
+        serialization.Encoding.PEM,
+        serialization.PrivateFormat.PKCS8,
+        serialization.NoEncryption(),
+    ))
+    private_key_path.chmod(0o600)
+
+    pk_path = private_key_path.with_suffix(".pub.pem")
+    pk_path.write_bytes(sk.public_key().public_bytes(
+        serialization.Encoding.PEM,
+        serialization.PublicFormat.SubjectPublicKeyInfo,
+    ))
+
+
+def hub_public_key_pem() -> bytes:
+    if _hub_pk_pem is None:
+        raise RuntimeError("Hub keypair not loaded — call load_hub_keypair() first")
+    return _hub_pk_pem
+
+
+# ── Password ──────────────────────────────────────────────────────────────────
+
+def hash_password(password: str) -> tuple[bytes, bytes]:
+    """Hash a password with Argon2id. Returns (hash, salt)."""
+    salt = os.urandom(16)
+    pw_hash = Argon2id(
+        salt=salt,
+        length=_ARGON2_KEY_LEN,
+        iterations=_ARGON2_ITERATIONS,
+        lanes=_ARGON2_LANES,
+        memory_cost=_ARGON2_MEMORY_COST,
+    ).derive(password.encode())
+    return pw_hash, salt
+
+
+def verify_password(password: str, pw_hash: bytes, salt: bytes) -> bool:
+    try:
+        Argon2id(
+            salt=salt,
+            length=_ARGON2_KEY_LEN,
+            iterations=_ARGON2_ITERATIONS,
+            lanes=_ARGON2_LANES,
+            memory_cost=_ARGON2_MEMORY_COST,
+        ).verify(password.encode(), pw_hash)
+        return True
+    except Exception:
+        return False
+
+
+# ── JWT ───────────────────────────────────────────────────────────────────────
+
+def issue_access_token(
+    user_id: str,
+    pk_user: str,
+    ttl: int = 3600,
+) -> str:
+    """
+    Issue a signed JWT access token.
+    Includes jti (UUID4) — required to prevent replay and enable revocation.
+    """
+    if _hub_sk_pem is None:
+        raise RuntimeError("Hub keypair not loaded")
+    now = int(time.time())
+    payload = {
+        "iss":     _hub_id,
+        "sub":     user_id,
+        "pk_user": pk_user,
+        "hub_id":  _hub_id,
+        "jti":     str(uuid.uuid4()),
+        "iat":     now,
+        "exp":     now + ttl,
+    }
+    return jwt.encode(payload, _hub_sk_pem, algorithm="EdDSA")
+
+
+def decode_access_token(token: str) -> dict:
+    """Verify and decode an access token. Raises on failure."""
+    if _hub_pk_pem is None:
+        raise RuntimeError("Hub keypair not loaded")
+    return jwt.decode(token, _hub_pk_pem, algorithms=["EdDSA"])
+
+
+# ── Refresh tokens ────────────────────────────────────────────────────────────
+
+def generate_refresh_token() -> tuple[str, str]:
+    """Return (raw_token, token_hash). Store hash; give raw to client."""
+    raw   = base64.urlsafe_b64encode(os.urandom(32)).decode()
+    hashed = blake3.blake3(raw.encode()).hexdigest()
+    return raw, hashed
+
+
+def hash_refresh_token(raw: str) -> str:
+    return blake3.blake3(raw.encode()).hexdigest()
diff --git a/packages/meshbay-hub/src/meshbay_hub/config.py b/packages/meshbay-hub/src/meshbay_hub/config.py
new file mode 100644
index 0000000..297ace7
--- /dev/null
+++ b/packages/meshbay-hub/src/meshbay_hub/config.py
@@ -0,0 +1,95 @@
+"""
+MeshBay Hub configuration.
+
+Priority (highest first):
+  1. Environment variables  (MESHBAY_*)
+  2. Config file            (/etc/meshbay/hub.toml or --config)
+  3. Built-in defaults
+
+Production config file example: /etc/meshbay/hub.toml
+"""
+
+import os
+from dataclasses import dataclass, field
+from pathlib import Path
+
+try:
+    import tomllib
+except ImportError:
+    import tomli as tomllib  # type: ignore[no-redef]
+
+DEFAULT_CONFIG_PATHS = [
+    Path("/etc/meshbay/hub.toml"),
+    Path.home() / ".config" / "meshbay" / "hub.toml",
+]
+
+
+@dataclass
+class DatabaseConfig:
+    url: str = "sqlite+aiosqlite:///:memory:"
+
+
+@dataclass
+class ServerConfig:
+    host:    str = "127.0.0.1"
+    port:    int = 8000
+    workers: int = 1
+
+
+@dataclass
+class HubIdentityConfig:
+    id:               str  = "meshbay.org"
+    private_key_path: Path = field(default_factory=lambda:
+        Path.home() / ".config" / "meshbay" / "hub_private.pem")
+
+
+@dataclass
+class JWTConfig:
+    access_token_ttl:  int = 3600          # 1 hour
+    refresh_token_ttl: int = 86400 * 30    # 30 days
+
+
+@dataclass
+class HubConfig:
+    db:       DatabaseConfig      = field(default_factory=DatabaseConfig)
+    server:   ServerConfig        = field(default_factory=ServerConfig)
+    identity: HubIdentityConfig   = field(default_factory=HubIdentityConfig)
+    jwt:      JWTConfig           = field(default_factory=JWTConfig)
+
+
+def load_config(path: Path | None = None) -> HubConfig:
+    cfg = HubConfig()
+
+    # Find and load TOML
+    candidates = [path] if path else DEFAULT_CONFIG_PATHS
+    for p in candidates:
+        if p and p.exists():
+            raw = tomllib.loads(p.read_text())
+            if db := raw.get("database", {}):
+                cfg.db.url = db.get("url", cfg.db.url)
+            if srv := raw.get("server", {}):
+                cfg.server.host    = srv.get("host",    cfg.server.host)
+                cfg.server.port    = srv.get("port",    cfg.server.port)
+                cfg.server.workers = srv.get("workers", cfg.server.workers)
+            if idn := raw.get("hub", {}):
+                cfg.identity.id = idn.get("id", cfg.identity.id)
+                if kp := idn.get("private_key_path"):
+                    cfg.identity.private_key_path = Path(kp).expanduser()
+            if jwt := raw.get("jwt", {}):
+                cfg.jwt.access_token_ttl  = jwt.get("access_token_ttl",  cfg.jwt.access_token_ttl)
+                cfg.jwt.refresh_token_ttl = jwt.get("refresh_token_ttl", cfg.jwt.refresh_token_ttl)
+            break
+
+    # Env var overrides
+    if url := os.environ.get("MESHBAY_DATABASE_URL"):
+        cfg.db.url = url
+    if host := os.environ.get("MESHBAY_HUB_HOST"):
+        cfg.server.host = host
+    if port := os.environ.get("MESHBAY_HUB_PORT"):
+        cfg.server.port = int(port)
+    if hub_id := os.environ.get("MESHBAY_HUB_ID"):
+        cfg.identity.id = hub_id
+    if kp := os.environ.get("MESHBAY_HUB_KEY"):
+        cfg.identity.private_key_path = Path(kp).expanduser()
+
+    return cfg
diff --git a/packages/meshbay-hub/src/meshbay_hub/daemon.py b/packages/meshbay-hub/src/meshbay_hub/daemon.py
index ff8158a..ff66fee 100644
--- a/packages/meshbay-hub/src/meshbay_hub/daemon.py
+++ b/packages/meshbay-hub/src/meshbay_hub/daemon.py
@@ -1,15 +1,36 @@
 """Entry point for the meshbay-hub systemd service."""
 
+import argparse
+import logging
+import sys
+from pathlib import Path
+
 import uvicorn
-from meshbay_hub.app import app  # noqa: F401
+
+from meshbay_hub.config import load_config
 
 
 def main() -> None:
+    parser = argparse.ArgumentParser(description="MeshBay Hub server")
+    parser.add_argument("--config", type=Path, default=None)
+    parser.add_argument("--log-level", default="INFO",
+                        choices=["DEBUG", "INFO", "WARNING", "ERROR"])
+    args = parser.parse_args()
+
+    logging.basicConfig(
+        level=getattr(logging, args.log_level),
+        format="%(asctime)s %(levelname)-8s %(name)s: %(message)s",
+    )
+
+    cfg = load_config(args.config)
+
     uvicorn.run(
-        "meshbay_hub.app:app",
-        host="127.0.0.1",
-        port=8000,
-        log_level="info",
+        "meshbay_hub.app:create_app",
+        factory=True,
+        host=cfg.server.host,
+        port=cfg.server.port,
+        workers=cfg.server.workers,
+        log_level=args.log_level.lower(),
     )