NLWeb Auth & Multitenancy

Before writing code

Fetch live docs:

1. Fetch https://github.com/nlweb-ai/NLWeb/blob/main/docs/setup-oauth.md for OAuth configuration.
2. Fetch https://github.com/nlweb-ai/NLWeb/blob/main/docs/nlweb-memory.md for conversation persistence.
3. Inspect AskAgent/python/webserver/routes/oauth.py for the current OAuth flow.
4. Inspect AskAgent/python/core/conversation_history.py and storage_providers/ for persistence backends.
5. Check config/config_oauth.yaml and config/config_storage.yaml for current keys.

Conceptual Architecture

NLWeb's Auth Model — What It Does and Doesn't Do

NLWeb ships OAuth-based user identification — it lets a logged-in user have persistent conversation memory tied to their identity. It does not ship:

• Fine-grained authorization (per-site ACLs)
• API key auth for service-to-service callers
• Multi-tenant data isolation at the retrieval layer

If you need any of those, you build them as middleware on top.

OAuth Providers Supported

Per config_oauth.yaml:

Adding a new provider means a new client class in the OAuth routes module + a config entry. Verify the current extensibility mechanism in the live code.

OAuth Routes

(Verify exact paths in webserver/routes/oauth.py.)

Session Storage

By default, NLWeb stores sessions in-memory or via an aiohttp session backend. For multi-instance deployments, configure a shared session store (Redis, etc.). The session cookie carries the user identity; conversation persistence keys off that identity.

Conversation Persistence

config_storage.yaml selects which storage backend persists conversations:

The choice often matches your retrieval backend so conversation search and content search share infrastructure. Anonymous users typically don't get persistence — verify if/how the config exposes this toggle.

Multitenancy via sites: Allowlist

config_nlweb.yaml has a sites: list of allowed site names. Queries with site= not in the list are rejected. Patterns:

Single-tenant: just enumerate your own sites.

Multi-customer SaaS: prefix every site with a tenant ID (tenant_a__products, tenant_b__products), and add middleware that:

1. Reads the authenticated user's tenant from the session
2. Rewrites incoming site params to scope to that tenant's sites only
3. Rejects queries asking for sites outside the tenant's scope

NLWeb does not ship this middleware — you write it.

Per-Tenant Data Isolation

At the retrieval layer:

• Cheap path: site naming convention as above. Single index, queries filter by site. Cheap but tenants share an index.
• Strong isolation: separate retrieval indexes / collections / databases per tenant. Configure NLWeb with multiple endpoints (e.g., qdrant_tenant_a, qdrant_tenant_b) and route based on the authenticated user.

The strong-isolation path requires more config wrangling but is the only safe choice for regulated tenants.

User Identity in Conversation Search

methods/conversation_search.py queries the conversation storage scoped to the current user. The user ID flows from the OAuth session into the handler context. Without OAuth, this tool returns empty.

Headers for Permission Signaling

NLWeb's in-stream "headers" (the message_type JSON objects in SSE) include usage_terms and rate_limits. These can carry per-user policy — e.g., a higher-tier user gets a higher rate_limits.daily_quota. NLWeb doesn't enforce this; the client agent inspects and respects it.

Implementation Guidance

Enabling OAuth

1. Register an OAuth app with the provider (e.g., GitHub OAuth Apps).
2. Set the redirect URI to https://your-host/api/oauth/callback/github.
3. Set env vars (verify exact names in config_oauth.yaml):

   GITHUB_OAUTH_CLIENT_ID=...
   GITHUB_OAUTH_CLIENT_SECRET=...
   

4. Edit config_oauth.yaml to enable the provider:

   providers:
     github:
       enabled: true
       scopes: ["read:user"]
   

5. Restart. Visit /api/oauth/login/github to test.

Adding Multi-Tenant Middleware

A sketch (aiohttp middleware):

@web.middleware
async def tenant_scope_middleware(request, handler):
    user = await get_user_from_session(request)
    if user is None:
        return web.json_response({"error": "auth required"}, status=401)

    requested_site = request.query.get("site") or ""
    allowed_prefix = f"{user['tenant_id']}__"
    if not requested_site.startswith(allowed_prefix):
        return web.json_response({"error": "site not in tenant scope"}, status=403)

    return await handler(request)

Register on the aiohttp app before NLWeb's own handlers. Verify the exact insertion point in webserver/aiohttp_server.py.

Persisting Conversations Per User

1. Pick a storage backend in config_storage.yaml (Qdrant for dev, Azure Search / ES for prod).
2. Ensure OAuth is on (anonymous users don't get persistence by default).
3. Verify the storage class records user_id on each conversation row — it does in current code; verify after upgrade.

Letting Anonymous Users Query Without Persistence

For public sites:

• Leave OAuth optional
• Allow anonymous /ask but skip persistence
• Disable conversation_search tool for anonymous users (it would return empty anyway)

Confirm the current behavior — anonymous policy has changed across releases.

API Keys for Service Callers

NLWeb does NOT ship API key auth out of the box. Add it as middleware:

@web.middleware
async def api_key_middleware(request, handler):
    key = request.headers.get("X-API-Key")
    if request.path.startswith("/api/oauth/"):
        return await handler(request)  # OAuth flow exempt
    if not is_valid_key(key):
        return web.json_response({"error": "invalid key"}, status=401)
    return await handler(request)

Issue keys via a separate admin endpoint or out-of-band.

Hardening Sessions for Multi-Instance

• Use a shared session backend (Redis via aiohttp-session redis storage).
• Set secure cookie flags (Secure, HttpOnly, SameSite=Lax).
• Rotate the session secret on a schedule.
• Set a sane session TTL.

Common Pitfalls

• OAuth callback URL mismatch — the provider rejects the redirect. Copy the URL byte-for-byte.
• In-memory sessions lose users on restart — wire a shared backend before going multi-instance.
• Conversations not persisting — storage backend not configured OR user is anonymous OR storage backend's index doesn't exist.
• Tenant leakage — middleware order is wrong, OR the storage backend isn't filtering by user. Pen-test before launch.
• who endpoint exposes tenant names — disable who_endpoint_enabled for multitenant deployments.

Always re-fetch the OAuth and storage docs from the live repo — auth code moves between releases.