Add custom API URL and model to AI settings

- Settings → AI: optional base URL and model name fields
- Defaults to Anthropic/OpenAI public APIs when left blank
- Custom URL enables Open WebUI, LM Studio, Ollama, and any OpenAI-compatible endpoint
- Parse endpoint uses custom base URL and model if configured
- Migration 0004: ai_base_url + ai_model columns on users
- OpenAI provider label updated to "OpenAI-compatible"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/alembic/versions/0004_ai_base_url.py

@@ -0,0 +1,23 @@
+"""add ai_base_url and ai_model to users
+
+Revision ID: 0004
+Revises: 0003
+Create Date: 2026-04-22
+"""
+from alembic import op
+import sqlalchemy as sa
+
+revision = "0004"
+down_revision = "0003"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column("users", sa.Column("ai_base_url", sa.Text, nullable=True))
+    op.add_column("users", sa.Column("ai_model", sa.Text, nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("users", "ai_model")
+    op.drop_column("users", "ai_base_url")

backend/app/api/v1/settings.py

@@ -20,11 +20,15 @@ SUPPORTED_PROVIDERS = {"anthropic", "openai"}
 class AiSettingsResponse(BaseModel):
     provider: str | None
     has_api_key: bool
+    base_url: str | None
+    model: str | None
 
 
 class AiSettingsSave(BaseModel):
     provider: str
-    api_key: str
+    api_key: str = ""
+    base_url: str = ""
+    model: str = ""
 
 
 @router.get("/ai", response_model=AiSettingsResponse)
@@ -32,6 +36,8 @@ async def get_ai_settings(user: User = Depends(get_current_user)):
     return AiSettingsResponse(
         provider=user.ai_provider,
         has_api_key=bool(user.ai_api_key_enc),
+        base_url=user.ai_base_url,
+        model=user.ai_model,
     )
 
 
@@ -43,17 +49,26 @@ async def save_ai_settings(
 ):
     if body.provider not in SUPPORTED_PROVIDERS:
         raise HTTPException(status_code=400, detail=f"Unsupported provider. Choose: {', '.join(SUPPORTED_PROVIDERS)}")
-    if not body.api_key.strip():
-        raise HTTPException(status_code=400, detail="api_key must not be empty")
 
-    encrypted = encrypt_field(body.api_key.strip())
+    values: dict = {
-    await db.execute(
+        "ai_provider": body.provider,
-        update(User)
+        "ai_base_url": body.base_url.rstrip("/") or None,
-        .where(User.id == user.id)
+        "ai_model": body.model.strip() or None,
-        .values(ai_provider=body.provider, ai_api_key_enc=encrypted)
+    }
-    )
+
+    if body.api_key.strip():
+        values["ai_api_key_enc"] = encrypt_field(body.api_key.strip())
+    elif not user.ai_api_key_enc:
+        raise HTTPException(status_code=400, detail="api_key is required when no key is saved yet")
+
+    await db.execute(update(User).where(User.id == user.id).values(**values))
     await db.commit()
-    return AiSettingsResponse(provider=body.provider, has_api_key=True)
+    return AiSettingsResponse(
+        provider=body.provider,
+        has_api_key=True,
+        base_url=values["ai_base_url"],
+        model=values["ai_model"],
+    )
 
 
 @router.delete("/ai", status_code=204)
@@ -64,6 +79,6 @@ async def clear_ai_settings(
     await db.execute(
         update(User)
         .where(User.id == user.id)
-        .values(ai_provider=None, ai_api_key_enc=None)
+        .values(ai_provider=None, ai_api_key_enc=None, ai_base_url=None, ai_model=None)
     )
     await db.commit()

backend/app/api/v1/transactions.py

@@ -331,8 +331,13 @@ async def parse_attachment(
         "Return ONLY the JSON object. No markdown, no explanation, no code fences."
     )
 
+    custom_base_url = (user_row.ai_base_url or "").rstrip("/")
+    custom_model = (user_row.ai_model or "").strip()
+
     try:
         if user_row.ai_provider == "anthropic":
+            base_url = custom_base_url or "https://api.anthropic.com"
+            model = custom_model or "claude-haiku-4-5-20251001"
             if mime_type == "application/pdf":
                 content_block = {
                     "type": "document",
@@ -343,16 +348,16 @@ async def parse_attachment(
                     "type": "image",
                     "source": {"type": "base64", "media_type": mime_type, "data": b64},
                 }
-            async with httpx.AsyncClient(timeout=30) as client:
+            async with httpx.AsyncClient(timeout=60) as client:
                 resp = await client.post(
-                    "https://api.anthropic.com/v1/messages",
+                    f"{base_url}/v1/messages",
                     headers={
                         "x-api-key": api_key,
                         "anthropic-version": "2023-06-01",
                         "content-type": "application/json",
                     },
                     json={
-                        "model": "claude-haiku-4-5-20251001",
+                        "model": model,
                         "max_tokens": 512,
                         "messages": [{"role": "user", "content": [content_block, {"type": "text", "text": prompt}]}],
                     },
@@ -361,14 +366,16 @@ async def parse_attachment(
             text = resp.json()["content"][0]["text"].strip()
 
         elif user_row.ai_provider == "openai":
-            if mime_type == "application/pdf":
+            base_url = custom_base_url or "https://api.openai.com"
+            model = custom_model or "gpt-4o-mini"
+            if mime_type == "application/pdf" and not custom_base_url:
                 raise HTTPException(status_code=400, detail="PDF parsing is not supported with the OpenAI provider. Use an image format or switch to Anthropic.")
-            async with httpx.AsyncClient(timeout=30) as client:
+            async with httpx.AsyncClient(timeout=60) as client:
                 resp = await client.post(
-                    "https://api.openai.com/v1/chat/completions",
+                    f"{base_url}/v1/chat/completions",
                     headers={"Authorization": f"Bearer {api_key}", "content-type": "application/json"},
                     json={
-                        "model": "gpt-4o-mini",
+                        "model": model,
                         "max_tokens": 512,
                         "messages": [{
                             "role": "user",

backend/app/db/models/user.py

@@ -31,6 +31,8 @@ class User(Base):
 
     ai_provider: Mapped[str | None] = mapped_column(Text, nullable=True)
     ai_api_key_enc: Mapped[bytes | None] = mapped_column(LargeBinary, nullable=True)
+    ai_base_url: Mapped[str | None] = mapped_column(Text, nullable=True)
+    ai_model: Mapped[str | None] = mapped_column(Text, nullable=True)
 
     accounts: Mapped[list["Account"]] = relationship(back_populates="user", lazy="noload")  # type: ignore[name-defined]
     sessions: Mapped[list["Session"]] = relationship(back_populates="user", lazy="noload")  # type: ignore[name-defined]

frontend/src/api/settings.ts

@@ -3,6 +3,15 @@ import { api } from "./client";
 export interface AiSettings {
   provider: string | null;
   has_api_key: boolean;
+  base_url: string | null;
+  model: string | null;
+}
+
+export interface AiSettingsSave {
+  provider: string;
+  api_key?: string;
+  base_url?: string;
+  model?: string;
 }
 
 export interface ParsedReceipt {
@@ -19,8 +28,8 @@ export async function getAiSettings(): Promise<AiSettings> {
   return data;
 }
 
-export async function saveAiSettings(provider: string, api_key: string): Promise<AiSettings> {
+export async function saveAiSettings(body: AiSettingsSave): Promise<AiSettings> {
-  const { data } = await api.put("/settings/ai", { provider, api_key });
+  const { data } = await api.put("/settings/ai", body);
   return data;
 }
 

frontend/src/pages/settings/SettingsPage.tsx

@@ -658,6 +658,8 @@ function AiSection() {
   const qc = useQueryClient();
   const [provider, setProvider] = useState("anthropic");
   const [apiKey, setApiKey]     = useState("");
+  const [baseUrl, setBaseUrl]   = useState("");
+  const [model, setModel]       = useState("");
   const [showKey, setShowKey]   = useState(false);
   const [success, setSuccess]   = useState("");
 
@@ -666,16 +668,23 @@ function AiSection() {
     queryFn: async () => {
       const d = await getAiSettings();
       if (d.provider) setProvider(d.provider);
+      if (d.base_url) setBaseUrl(d.base_url);
+      if (d.model) setModel(d.model);
       return d;
     },
   });
 
   const saveMutation = useMutation({
-    mutationFn: () => saveAiSettings(provider, apiKey),
+    mutationFn: () => saveAiSettings({
+      provider,
+      api_key: apiKey,
+      base_url: baseUrl,
+      model,
+    }),
     onSuccess: () => {
       qc.invalidateQueries({ queryKey: ["ai-settings"] });
       setApiKey("");
-      setSuccess("API key saved");
+      setSuccess("Settings saved");
       setTimeout(() => setSuccess(""), 3000);
     },
   });
@@ -684,11 +693,15 @@ function AiSection() {
     mutationFn: clearAiSettings,
     onSuccess: () => {
       qc.invalidateQueries({ queryKey: ["ai-settings"] });
-      setSuccess("API key removed");
+      setBaseUrl(""); setModel("");
+      setSuccess("AI settings removed");
       setTimeout(() => setSuccess(""), 3000);
     },
   });
 
+  const defaultModel = provider === "anthropic" ? "claude-haiku-4-5-20251001" : "gpt-4o-mini";
+  const defaultUrl   = provider === "anthropic" ? "https://api.anthropic.com" : "https://api.openai.com";
+
   return (
     <div className={cardCls}>
       <div className="flex items-center gap-2">
@@ -723,8 +736,11 @@ function AiSection() {
           className={inputCls}
         >
           <option value="anthropic">Anthropic (Claude)</option>
-          <option value="openai">OpenAI (GPT-4o mini)</option>
+          <option value="openai">OpenAI-compatible</option>
         </select>
+        <p className="text-xs text-muted-foreground mt-1">
+          OpenAI-compatible works with Open WebUI, LM Studio, Ollama, and any OpenAI-spec endpoint.
+        </p>
       </div>
 
       <div>
@@ -737,7 +753,7 @@ function AiSection() {
             value={apiKey}
             onChange={e => setApiKey(e.target.value)}
             className={cn(inputCls, "pr-10")}
-            placeholder={current?.has_api_key ? "••••••••••••••••" : provider === "anthropic" ? "sk-ant-..." : "sk-..."}
+            placeholder={current?.has_api_key ? "••••••••••••••••" : provider === "anthropic" ? "sk-ant-..." : "sk-... (use any value if not required)"}
           />
           <button
             type="button"
@@ -747,10 +763,33 @@ function AiSection() {
             {showKey ? <EyeOff className="w-4 h-4" /> : <Eye className="w-4 h-4" />}
           </button>
         </div>
+      </div>
+
+      <div>
+        <label className="text-sm font-medium block mb-1.5">Custom API URL <span className="text-muted-foreground font-normal">(optional)</span></label>
+        <input
+          type="text"
+          value={baseUrl}
+          onChange={e => setBaseUrl(e.target.value)}
+          className={inputCls}
+          placeholder={defaultUrl}
+        />
         <p className="text-xs text-muted-foreground mt-1">
-          {provider === "anthropic"
+          Leave blank to use the default. For Open WebUI: <code className="bg-secondary px-1 rounded">http://your-server:3000</code>
-            ? "Get your key at console.anthropic.com → API Keys"
+        </p>
-            : "Get your key at platform.openai.com → API Keys"}
+      </div>
+
+      <div>
+        <label className="text-sm font-medium block mb-1.5">Model <span className="text-muted-foreground font-normal">(optional)</span></label>
+        <input
+          type="text"
+          value={model}
+          onChange={e => setModel(e.target.value)}
+          className={inputCls}
+          placeholder={defaultModel}
+        />
+        <p className="text-xs text-muted-foreground mt-1">
+          Leave blank to use the default. For Open WebUI, enter the model name exactly as shown in its interface.
         </p>
       </div>
 
@@ -761,7 +800,7 @@ function AiSection() {
           className="flex items-center gap-2 bg-primary text-primary-foreground px-4 py-2 rounded-lg text-sm font-medium hover:bg-primary/90 disabled:opacity-50 transition-colors"
         >
           {saveMutation.isPending && <Loader2 className="w-4 h-4 animate-spin" />}
-          {current?.has_api_key && !apiKey ? "Update provider" : "Save API key"}
+          Save settings
         </button>
 
         {current?.has_api_key && (