diff --git a/completions/mcpctl.bash b/completions/mcpctl.bash
index a889844..ed1b7e1 100644
--- a/completions/mcpctl.bash
+++ b/completions/mcpctl.bash
@@ -185,7 +185,7 @@ _mcpctl() {
             COMPREPLY=($(compgen -W "--data --force -h --help" -- "$cur"))
             ;;
           llm)
-            COMPREPLY=($(compgen -W "--type --model --url --tier --description --api-key-ref --extra --force -h --help" -- "$cur"))
+            COMPREPLY=($(compgen -W "--type --model --url --tier --description --api-key-ref --extra --force --skip-auth-check -h --help" -- "$cur"))
             ;;
           agent)
             COMPREPLY=($(compgen -W "--llm --project --description --system-prompt --system-prompt-file --proxy-model --default-temperature --default-top-p --default-top-k --default-max-tokens --default-seed --default-stop --default-extra --default-params-file --force -h --help" -- "$cur"))
diff --git a/completions/mcpctl.fish b/completions/mcpctl.fish
index ce00dbc..e02363f 100644
--- a/completions/mcpctl.fish
+++ b/completions/mcpctl.fish
@@ -331,6 +331,7 @@ complete -c mcpctl -n "__mcpctl_subcmd_active create llm" -l description -d 'Des
 complete -c mcpctl -n "__mcpctl_subcmd_active create llm" -l api-key-ref -d 'API key reference in SECRET/KEY form (e.g. anthropic-key/token)' -x
 complete -c mcpctl -n "__mcpctl_subcmd_active create llm" -l extra -d 'Extra config key=value (repeat)' -x
 complete -c mcpctl -n "__mcpctl_subcmd_active create llm" -l force -d 'Update if already exists'
+complete -c mcpctl -n "__mcpctl_subcmd_active create llm" -l skip-auth-check -d 'Skip the upstream auth probe (for offline registration before infra exists)'
 
 # create agent options
 complete -c mcpctl -n "__mcpctl_subcmd_active create agent" -l llm -d 'Pinned Llm (see `mcpctl get llms`)' -x
diff --git a/src/cli/src/commands/create.ts b/src/cli/src/commands/create.ts
index 2a92112..5e5122a 100644
--- a/src/cli/src/commands/create.ts
+++ b/src/cli/src/commands/create.ts
@@ -264,6 +264,7 @@ export function createCreateCommand(deps: CreateCommandDeps): Command {
     .option('--api-key-ref <ref>', 'API key reference in SECRET/KEY form (e.g. anthropic-key/token)')
     .option('--extra <entry>', 'Extra config key=value (repeat)', collect, [])
     .option('--force', 'Update if already exists')
+    .option('--skip-auth-check', 'Skip the upstream auth probe (for offline registration before infra exists)')
     .action(async (name: string, opts) => {
       const body: Record<string, unknown> = {
         name,
@@ -290,6 +291,11 @@ export function createCreateCommand(deps: CreateCommandDeps): Command {
         }
         body.extraConfig = extra;
       }
+      // _skipAuthCheck is a side-channel field consumed (and stripped) by the
+      // mcpd route — it never makes it into the Llm row. mcpd defaults to
+      // running an auth probe at create/update time so wrong tokens fail fast
+      // with a 422 instead of silently 502'ing on first chat.
+      if (opts.skipAuthCheck === true) body._skipAuthCheck = true;
 
       try {
         const row = await client.post<{ id: string; name: string }>('/api/v1/llms', body);
diff --git a/src/cli/src/index.ts b/src/cli/src/index.ts
index a01ac82..6a0485f 100644
--- a/src/cli/src/index.ts
+++ b/src/cli/src/index.ts
@@ -40,14 +40,31 @@ export function createProgram(): Command {
   program.addCommand(createLoginCommand());
   program.addCommand(createLogoutCommand());
 
-  // Resolve target URL: --direct goes to mcpd, default goes to mcplocal
+  // Resolve target URL: --direct goes to mcpd, default goes to mcplocal.
+  //
+  // Commander's `program.opts()` returns the default values until
+  // `program.parse(argv)` runs — but commands (and ApiClient) need the
+  // resolved baseUrl at construction time. The chicken-and-egg meant
+  // `--direct` was previously a no-op for ApiClient: every command went to
+  // mcplocal regardless. Some commands accidentally still worked because
+  // mcplocal forwards plain `/api/v1/*` to mcpd, but flows that need direct
+  // SSE streaming (e.g. `mcpctl chat`) went to mcplocal:3200, which doesn't
+  // route them.
+  //
+  // Fix: peek at process.argv directly for the two global flags we need
+  // before Commander's full parse runs.
   const config = loadConfig();
   const creds = loadCredentials();
-  const opts = program.opts();
+  const argv = process.argv;
+  const directFlag = argv.includes('--direct');
+  const daemonUrlIdx = argv.indexOf('--daemon-url');
+  const daemonUrlVal = daemonUrlIdx > -1 && daemonUrlIdx + 1 < argv.length
+    ? argv[daemonUrlIdx + 1]
+    : undefined;
   let baseUrl: string;
-  if (opts.daemonUrl) {
-    baseUrl = opts.daemonUrl as string;
-  } else if (opts.direct) {
+  if (daemonUrlVal !== undefined) {
+    baseUrl = daemonUrlVal;
+  } else if (directFlag) {
     baseUrl = config.mcpdUrl;
   } else {
     baseUrl = config.mcplocalUrl;
diff --git a/src/mcpd/src/main.ts b/src/mcpd/src/main.ts
index 499cf8b..4e9845c 100644
--- a/src/mcpd/src/main.ts
+++ b/src/mcpd/src/main.ts
@@ -415,8 +415,17 @@ async function main(): Promise<void> {
     backends: secretBackendService,
     rotator: secretBackendRotator,
   });
-  const llmService = new LlmService(llmRepo, secretService);
   const llmAdapters = new LlmAdapterRegistry();
+  // LlmService takes the adapter registry so create()/update() can run an
+  // auth probe at registration time. Keeps registration honest: misconfigured
+  // tokens or wrong URLs surface as a 422 at create, not as a "fetch failed"
+  // 502 at first chat. Logger forwards inconclusive probes (network down,
+  // proxy doesn't expose /v1/models) to mcpd's structured log so operators
+  // can still see them without blocking registration.
+  const llmService = new LlmService(llmRepo, secretService, {
+    adapters: llmAdapters,
+    log: { warn: (msg) => app.log.warn(msg) },
+  });
   // AgentService + ChatService get fully wired below once projectService and
   // mcpProxyService are constructed (ChatService needs them via the
   // ChatToolDispatcher bridge).
diff --git a/src/mcpd/src/routes/llms.ts b/src/mcpd/src/routes/llms.ts
index 3e0bf79..7d34571 100644
--- a/src/mcpd/src/routes/llms.ts
+++ b/src/mcpd/src/routes/llms.ts
@@ -1,5 +1,6 @@
 import type { FastifyInstance } from 'fastify';
 import type { LlmService } from '../services/llm.service.js';
+import { LlmAuthVerificationError } from '../services/llm.service.js';
 import { NotFoundError, ConflictError } from '../services/mcp-server.service.js';
 
 export function registerLlmRoutes(
@@ -31,7 +32,13 @@ export function registerLlmRoutes(
 
   app.post('/api/v1/llms', async (request, reply) => {
     try {
-      const row = await service.create(request.body);
+      // Body field `_skipAuthCheck`: opt-out for offline registration (e.g.
+      // wiring config before the upstream is reachable). Stripped from the
+      // body before validation.
+      const body = (request.body ?? {}) as Record<string, unknown>;
+      const skipAuthCheck = body['_skipAuthCheck'] === true;
+      delete body['_skipAuthCheck'];
+      const row = await service.create(body, { skipAuthCheck });
       reply.code(201);
       return row;
     } catch (err) {
@@ -39,18 +46,29 @@ export function registerLlmRoutes(
         reply.code(409);
         return { error: err.message };
       }
+      if (err instanceof LlmAuthVerificationError) {
+        reply.code(422);
+        return { error: err.message, status: err.status };
+      }
       throw err;
     }
   });
 
   app.put<{ Params: { id: string } }>('/api/v1/llms/:id', async (request, reply) => {
     try {
-      return await service.update(request.params.id, request.body);
+      const body = (request.body ?? {}) as Record<string, unknown>;
+      const skipAuthCheck = body['_skipAuthCheck'] === true;
+      delete body['_skipAuthCheck'];
+      return await service.update(request.params.id, body, { skipAuthCheck });
     } catch (err) {
       if (err instanceof NotFoundError) {
         reply.code(404);
         return { error: err.message };
       }
+      if (err instanceof LlmAuthVerificationError) {
+        reply.code(422);
+        return { error: err.message, status: err.status };
+      }
       throw err;
     }
   });
diff --git a/src/mcpd/src/services/llm.service.ts b/src/mcpd/src/services/llm.service.ts
index 3a92410..6dd3932 100644
--- a/src/mcpd/src/services/llm.service.ts
+++ b/src/mcpd/src/services/llm.service.ts
@@ -13,6 +13,8 @@
 import type { Llm } from '@prisma/client';
 import type { ILlmRepository } from '../repositories/llm.repository.js';
 import type { SecretService } from './secret.service.js';
+import type { LlmAdapterRegistry } from './llm/dispatcher.js';
+import type { InferContext } from './llm/types.js';
 import {
   CreateLlmSchema,
   UpdateLlmSchema,
@@ -21,6 +23,22 @@ import {
 } from '../validation/llm.schema.js';
 import { NotFoundError, ConflictError } from './mcp-server.service.js';
 
+/** Dependencies for auth verification at create/update time. */
+export interface LlmServiceDeps {
+  /** Adapter registry to run the auth probe. Optional in tests / bootstrap. */
+  adapters?: LlmAdapterRegistry;
+  /** Logger for unreachable/unexpected probe outcomes. */
+  log?: { warn: (msg: string) => void };
+}
+
+/** Thrown when the auth probe fails decisively (401/403 from upstream). */
+export class LlmAuthVerificationError extends Error {
+  constructor(public readonly status: number, public readonly body: string, message: string) {
+    super(message);
+    this.name = 'LlmAuthVerificationError';
+  }
+}
+
 /** Shape returned by API layer — merges DB row with a human-readable apiKeyRef. */
 export interface LlmView {
   id: string;
@@ -41,6 +59,7 @@ export class LlmService {
   constructor(
     private readonly repo: ILlmRepository,
     private readonly secrets: SecretService,
+    private readonly verifyDeps: LlmServiceDeps = {},
   ) {}
 
   async list(): Promise<LlmView[]> {
@@ -60,12 +79,29 @@ export class LlmService {
     return this.toView(row);
   }
 
-  async create(input: unknown): Promise<LlmView> {
+  async create(input: unknown, opts: { skipAuthCheck?: boolean } = {}): Promise<LlmView> {
     const data = CreateLlmSchema.parse(input);
     const existing = await this.repo.findByName(data.name);
     if (existing !== null) throw new ConflictError(`Llm already exists: ${data.name}`);
 
     const apiKeyFields = await this.resolveApiKeyRefToIds(data.apiKeyRef);
+
+    // Auth probe: catch wrong tokens / wrong URLs at registration time, not
+    // at first chat. Skipped when there's no key (probe would be meaningless)
+    // or the caller explicitly opted out (e.g. wiring config before infra
+    // exists). The probe is also skipped when no adapters registry was
+    // injected — keeps tests + bootstrap simple.
+    if (!opts.skipAuthCheck && apiKeyFields.id !== null && this.verifyDeps.adapters !== undefined) {
+      await this.runAuthProbe({
+        name: data.name,
+        type: data.type,
+        model: data.model,
+        url: data.url ?? '',
+        apiKeyRef: data.apiKeyRef ?? null,
+        extraConfig: data.extraConfig,
+      });
+    }
+
     const row = await this.repo.create({
       name: data.name,
       type: data.type,
@@ -80,9 +116,9 @@ export class LlmService {
     return this.toView(row);
   }
 
-  async update(id: string, input: unknown): Promise<LlmView> {
+  async update(id: string, input: unknown, opts: { skipAuthCheck?: boolean } = {}): Promise<LlmView> {
     const data = UpdateLlmSchema.parse(input);
-    await this.getById(id);
+    const before = await this.getById(id);
 
     const updateFields: Parameters<ILlmRepository['update']>[1] = {};
     if (data.model !== undefined) updateFields.model = data.model;
@@ -103,10 +139,93 @@ export class LlmService {
       }
     }
 
+    // Auth probe runs whenever any field that affects auth (apiKeyRef OR url)
+    // is changing, OR whenever the caller asks via skipAuthCheck=false. The
+    // probe uses the post-update view (new key + new url + same type/model).
+    const authAffectingChange = data.apiKeyRef !== undefined || data.url !== undefined;
+    const willHaveKey = data.apiKeyRef === null
+      ? false
+      : data.apiKeyRef !== undefined || before.apiKeyRef !== null;
+    if (authAffectingChange && !opts.skipAuthCheck && willHaveKey && this.verifyDeps.adapters !== undefined) {
+      await this.runAuthProbe({
+        name: before.name,
+        type: before.type,
+        model: data.model ?? before.model,
+        url: data.url ?? before.url,
+        apiKeyRef: data.apiKeyRef === undefined ? before.apiKeyRef : data.apiKeyRef,
+        extraConfig: data.extraConfig ?? before.extraConfig,
+      });
+    }
+
     const row = await this.repo.update(id, updateFields);
     return this.toView(row);
   }
 
+  /**
+   * Run a cheap auth probe against the upstream provider. Throws
+   * `LlmAuthVerificationError` on a definitive auth failure (401/403).
+   * Logs and swallows transient network/unexpected errors — those are not
+   * fatal at registration time.
+   */
+  private async runAuthProbe(snap: {
+    name: string;
+    type: string;
+    model: string;
+    url: string;
+    apiKeyRef: ApiKeyRef | null;
+    extraConfig: Record<string, unknown>;
+  }): Promise<void> {
+    if (snap.apiKeyRef === null) return;
+    if (this.verifyDeps.adapters === undefined) return;
+    let apiKey: string;
+    try {
+      const secret = await this.secrets.getByName(snap.apiKeyRef.name);
+      const data = await this.secrets.resolveData(secret);
+      const v = data[snap.apiKeyRef.key];
+      if (v === undefined || v === '') {
+        throw new LlmAuthVerificationError(0, '', `Llm '${snap.name}' apiKeyRef points at empty secret data`);
+      }
+      apiKey = v;
+    } catch (err) {
+      if (err instanceof LlmAuthVerificationError) throw err;
+      // Secret resolution failure — bail with a clean error rather than
+      // letting it bubble as a generic 500.
+      throw new LlmAuthVerificationError(0, '', `Llm '${snap.name}' apiKeyRef could not be resolved: ${(err as Error).message}`);
+    }
+    let adapter;
+    try {
+      adapter = this.verifyDeps.adapters.get(snap.type);
+    } catch (err) {
+      // Provider type unsupported by the registry — that's a config error,
+      // surface it now.
+      throw new LlmAuthVerificationError(0, '', `Llm '${snap.name}' type '${snap.type}' has no adapter: ${(err as Error).message}`);
+    }
+    const ctx: InferContext = {
+      body: { model: snap.model, messages: [] },
+      modelOverride: snap.model,
+      apiKey,
+      url: snap.url,
+      extraConfig: snap.extraConfig,
+    };
+    const result = await adapter.verifyAuth(ctx);
+    if (result.ok) return;
+    if (result.reason === 'auth') {
+      throw new LlmAuthVerificationError(
+        result.status,
+        result.body,
+        `Llm '${snap.name}' auth check failed: ${snap.url || '(default URL)'} returned HTTP ${String(result.status)}. ` +
+        `Body: ${result.body.slice(0, 400)}`,
+      );
+    }
+    // unreachable / unexpected — warn but allow registration. The user might
+    // be wiring config before the upstream is reachable, or hitting a
+    // proxy that doesn't expose /v1/models.
+    const reason = result.reason === 'unreachable' ? `unreachable (${result.error})` : `HTTP ${String(result.status)} (${result.body.slice(0, 200)})`;
+    this.verifyDeps.log?.warn(
+      `Llm '${snap.name}': auth probe inconclusive — ${reason}. Registration succeeded; first inference call will surface any real issue.`,
+    );
+  }
+
   async delete(id: string): Promise<void> {
     await this.getById(id);
     await this.repo.delete(id);
diff --git a/src/mcpd/src/services/llm/adapters/anthropic.ts b/src/mcpd/src/services/llm/adapters/anthropic.ts
index 18c2fef..4f2f185 100644
--- a/src/mcpd/src/services/llm/adapters/anthropic.ts
+++ b/src/mcpd/src/services/llm/adapters/anthropic.ts
@@ -23,6 +23,7 @@ import type {
   StreamingChunk,
   AdapterDeps,
   OpenAiMessage,
+  VerifyAuthResult,
 } from '../types.js';
 
 const DEFAULT_ANTHROPIC_URL = 'https://api.anthropic.com';
@@ -146,6 +147,40 @@ export class AnthropicAdapter implements LlmAdapter {
     yield { data: '[DONE]', done: true };
   }
 
+  /**
+   * Anthropic doesn't expose a list-models or auth-only endpoint, so probe
+   * with the cheapest possible /v1/messages call (1 max_token, "ping"
+   * prompt). The point is to exercise the auth header, not to generate.
+   * Auth failures here are 401 with `{"type":"authentication_error"}` —
+   * caught and surfaced. Network failures bubble up as `unreachable`.
+   */
+  async verifyAuth(ctx: InferContext): Promise<VerifyAuthResult> {
+    const url = (ctx.url !== '' ? ctx.url : DEFAULT_ANTHROPIC_URL).replace(/\/+$/, '');
+    let res: Response;
+    try {
+      res = await this.fetchImpl(`${url}/v1/messages`, {
+        method: 'POST',
+        headers: this.headers(ctx),
+        body: JSON.stringify({
+          model: ctx.body.model !== '' ? ctx.body.model : ctx.modelOverride,
+          max_tokens: 1,
+          messages: [{ role: 'user', content: 'ping' }],
+        }),
+      });
+    } catch (err) {
+      return { ok: false, reason: 'unreachable', error: (err as Error).message };
+    }
+    if (res.ok) return { ok: true };
+    const body = await res.text().catch(() => '');
+    if (res.status === 401 || res.status === 403) {
+      return { ok: false, reason: 'auth', status: res.status, body };
+    }
+    // 400s on a bad model name are still proof the auth worked. Report
+    // those as `unexpected` (warn) rather than `auth` (fail) so the user
+    // can register the Llm with a typo'd model and fix it later.
+    return { ok: false, reason: 'unexpected', status: res.status, body };
+  }
+
   private headers(ctx: InferContext): Record<string, string> {
     return {
       'Content-Type': 'application/json',
diff --git a/src/mcpd/src/services/llm/adapters/openai-passthrough.ts b/src/mcpd/src/services/llm/adapters/openai-passthrough.ts
index 8d9c2dd..ddad8e2 100644
--- a/src/mcpd/src/services/llm/adapters/openai-passthrough.ts
+++ b/src/mcpd/src/services/llm/adapters/openai-passthrough.ts
@@ -11,7 +11,7 @@
  *   - deepseek → https://api.deepseek.com
  *   - vllm/ollama → must be configured; these have no canonical public URL.
  */
-import type { LlmAdapter, InferContext, NonStreamingResult, StreamingChunk, AdapterDeps } from '../types.js';
+import type { LlmAdapter, InferContext, NonStreamingResult, StreamingChunk, AdapterDeps, VerifyAuthResult } from '../types.js';
 
 const DEFAULT_URLS: Record<string, string> = {
   openai: 'https://api.openai.com',
@@ -88,6 +88,40 @@ export class OpenAiPassthroughAdapter implements LlmAdapter {
     yield { data: '[DONE]', done: true };
   }
 
+  /**
+   * Probe `GET <url>/v1/models` with the configured auth header. OpenAI,
+   * vLLM, LiteLLM, DeepSeek, Ollama (in openai-compat mode) all expose this
+   * endpoint and it's gated by the same auth as chat/completions. Cheap (no
+   * generation), idempotent, and the response shape is a stable
+   * `{ data: [...] }` array.
+   */
+  async verifyAuth(ctx: InferContext): Promise<VerifyAuthResult> {
+    let url: string;
+    try {
+      url = this.endpointUrl(ctx.url);
+    } catch (err) {
+      return { ok: false, reason: 'unexpected', status: 0, body: (err as Error).message };
+    }
+    let res: Response;
+    try {
+      res = await this.fetchImpl(`${url}/v1/models`, {
+        method: 'GET',
+        headers: this.headers(ctx),
+      });
+    } catch (err) {
+      return { ok: false, reason: 'unreachable', error: (err as Error).message };
+    }
+    if (res.ok) return { ok: true };
+    const body = await res.text().catch(() => '');
+    if (res.status === 401 || res.status === 403) {
+      return { ok: false, reason: 'auth', status: res.status, body };
+    }
+    // Some providers don't expose /v1/models (e.g. a stripped LiteLLM proxy).
+    // 404 + non-OAI providers shouldn't hard-block registration — caller
+    // treats `unexpected` as a warning, not a failure.
+    return { ok: false, reason: 'unexpected', status: res.status, body };
+  }
+
   private endpointUrl(url: string): string {
     if (url !== '') return url.replace(/\/+$/, '');
     const def = DEFAULT_URLS[this.kind];
diff --git a/src/mcpd/src/services/llm/types.ts b/src/mcpd/src/services/llm/types.ts
index 2e78be7..fd75694 100644
--- a/src/mcpd/src/services/llm/types.ts
+++ b/src/mcpd/src/services/llm/types.ts
@@ -63,8 +63,30 @@ export interface LlmAdapter {
    * provider-native stream formats into OpenAI `chat.completion.chunk`s.
    */
   stream(ctx: InferContext): AsyncGenerator<StreamingChunk>;
+  /**
+   * Cheap auth probe used at Llm create/update time. Should pick the cheapest
+   * upstream call that exercises the auth header — typically a list-models
+   * endpoint or a 1-token messages call.
+   *
+   * Returns one of:
+   *   - { ok: true }                                  — auth succeeded
+   *   - { ok: false, reason: 'auth', status, body }  — upstream said no (401/403)
+   *   - { ok: false, reason: 'unreachable', error }  — network/DNS/timeout
+   *   - { ok: false, reason: 'unexpected', status, body } — couldn't tell
+   *
+   * Callers (LlmService.create/update) throw on `auth`, warn-only on
+   * `unreachable`, and warn-only on `unexpected`. The point is to fail fast on
+   * provably wrong credentials at registration time.
+   */
+  verifyAuth(ctx: InferContext): Promise<VerifyAuthResult>;
 }
 
+export type VerifyAuthResult =
+  | { ok: true }
+  | { ok: false; reason: 'auth'; status: number; body: string }
+  | { ok: false; reason: 'unreachable'; error: string }
+  | { ok: false; reason: 'unexpected'; status: number; body: string };
+
 export interface AdapterDeps {
   fetch?: typeof globalThis.fetch;
 }
diff --git a/src/mcpd/tests/llm-adapters.test.ts b/src/mcpd/tests/llm-adapters.test.ts
index e80991b..045ac88 100644
--- a/src/mcpd/tests/llm-adapters.test.ts
+++ b/src/mcpd/tests/llm-adapters.test.ts
@@ -208,3 +208,102 @@ describe('LlmAdapterRegistry', () => {
     expect(() => reg.get('bogus')).toThrow(UnsupportedProviderError);
   });
 });
+
+describe('verifyAuth — registration-time probe', () => {
+  it('OpenAI passthrough: 200 from /v1/models → ok', async () => {
+    const fetchImpl = mockFetch([
+      { match: /\/v1\/models$/, status: 200, body: { data: [{ id: 'gpt-4o-mini' }] } },
+    ]);
+    const adapter = new OpenAiPassthroughAdapter('openai', { fetch: fetchImpl as unknown as typeof fetch });
+    const result = await adapter.verifyAuth(makeCtx({ url: 'http://lite:4000', apiKey: 'sk-good' }));
+    expect(result).toEqual({ ok: true });
+    expect(fetchImpl).toHaveBeenCalledWith('http://lite:4000/v1/models', expect.objectContaining({ method: 'GET' }));
+    const callInit = fetchImpl.mock.calls[0][1] as RequestInit;
+    expect((callInit.headers as Record<string, string>)['Authorization']).toBe('Bearer sk-good');
+  });
+
+  it('OpenAI passthrough: 401 → reason=auth (caller throws)', async () => {
+    const fetchImpl = mockFetch([
+      { match: /\/v1\/models$/, status: 401, text: '{"error":"invalid_api_key"}' },
+    ]);
+    const adapter = new OpenAiPassthroughAdapter('openai', { fetch: fetchImpl as unknown as typeof fetch });
+    const result = await adapter.verifyAuth(makeCtx({ url: 'http://lite:4000', apiKey: 'sk-bad' }));
+    expect(result.ok).toBe(false);
+    if (!result.ok) {
+      expect(result.reason).toBe('auth');
+      if (result.reason === 'auth') {
+        expect(result.status).toBe(401);
+        expect(result.body).toContain('invalid_api_key');
+      }
+    }
+  });
+
+  it('OpenAI passthrough: 403 → reason=auth', async () => {
+    const fetchImpl = mockFetch([
+      { match: /\/v1\/models$/, status: 403, text: 'forbidden' },
+    ]);
+    const adapter = new OpenAiPassthroughAdapter('openai', { fetch: fetchImpl as unknown as typeof fetch });
+    const result = await adapter.verifyAuth(makeCtx({ url: 'http://lite:4000', apiKey: 'k' }));
+    expect(result.ok).toBe(false);
+    if (!result.ok) expect(result.reason).toBe('auth');
+  });
+
+  it('OpenAI passthrough: 404 (proxy without /v1/models) → reason=unexpected (warn-only)', async () => {
+    const fetchImpl = mockFetch([
+      { match: /\/v1\/models$/, status: 404, text: 'not found' },
+    ]);
+    const adapter = new OpenAiPassthroughAdapter('openai', { fetch: fetchImpl as unknown as typeof fetch });
+    const result = await adapter.verifyAuth(makeCtx({ url: 'http://lite:4000', apiKey: 'k' }));
+    expect(result.ok).toBe(false);
+    if (!result.ok) expect(result.reason).toBe('unexpected');
+  });
+
+  it('OpenAI passthrough: network error → reason=unreachable (warn-only)', async () => {
+    const fetchImpl = vi.fn(async () => { throw new Error('ECONNREFUSED 127.0.0.1:9999'); });
+    const adapter = new OpenAiPassthroughAdapter('openai', { fetch: fetchImpl as unknown as typeof fetch });
+    const result = await adapter.verifyAuth(makeCtx({ url: 'http://localhost:9999', apiKey: 'k' }));
+    expect(result.ok).toBe(false);
+    if (!result.ok) {
+      expect(result.reason).toBe('unreachable');
+      if (result.reason === 'unreachable') {
+        expect(result.error).toContain('ECONNREFUSED');
+      }
+    }
+  });
+
+  it('Anthropic: 200 from /v1/messages probe → ok', async () => {
+    const fetchImpl = mockFetch([
+      { match: /\/v1\/messages$/, status: 200, body: { id: 'msg_x', content: [{ type: 'text', text: 'pong' }] } },
+    ]);
+    const adapter = new AnthropicAdapter({ fetch: fetchImpl as unknown as typeof fetch });
+    const result = await adapter.verifyAuth(makeCtx({ url: 'https://api.anthropic.com', apiKey: 'sk-ant-good' }));
+    expect(result.ok).toBe(true);
+    const callInit = fetchImpl.mock.calls[0][1] as RequestInit;
+    expect((callInit.headers as Record<string, string>)['x-api-key']).toBe('sk-ant-good');
+    const reqBody = JSON.parse(callInit.body as string) as { max_tokens: number };
+    expect(reqBody.max_tokens).toBe(1);
+  });
+
+  it('Anthropic: 401 → reason=auth', async () => {
+    const fetchImpl = mockFetch([
+      { match: /\/v1\/messages$/, status: 401, text: '{"type":"authentication_error"}' },
+    ]);
+    const adapter = new AnthropicAdapter({ fetch: fetchImpl as unknown as typeof fetch });
+    const result = await adapter.verifyAuth(makeCtx({ apiKey: 'bad' }));
+    expect(result.ok).toBe(false);
+    if (!result.ok) expect(result.reason).toBe('auth');
+  });
+
+  it('Anthropic: 400 (typo\'d model) → reason=unexpected, NOT auth', async () => {
+    // Auth was fine; the request was rejected for a different reason. We
+    // don't want to block registration on bad model names — that error
+    // surfaces at chat time when the user actually picks a model.
+    const fetchImpl = mockFetch([
+      { match: /\/v1\/messages$/, status: 400, text: '{"error":"model not found"}' },
+    ]);
+    const adapter = new AnthropicAdapter({ fetch: fetchImpl as unknown as typeof fetch });
+    const result = await adapter.verifyAuth(makeCtx({ apiKey: 'sk-ant-x', modelOverride: 'claude-fake' }));
+    expect(result.ok).toBe(false);
+    if (!result.ok) expect(result.reason).toBe('unexpected');
+  });
+});
diff --git a/src/mcpd/tests/llm-service.test.ts b/src/mcpd/tests/llm-service.test.ts
index 78af3e3..5bfc983 100644
--- a/src/mcpd/tests/llm-service.test.ts
+++ b/src/mcpd/tests/llm-service.test.ts
@@ -1,5 +1,5 @@
 import { describe, it, expect, vi } from 'vitest';
-import { LlmService } from '../src/services/llm.service.js';
+import { LlmService, LlmAuthVerificationError } from '../src/services/llm.service.js';
 import type { ILlmRepository } from '../src/repositories/llm.repository.js';
 import type { Llm, Secret } from '@prisma/client';
 
@@ -229,4 +229,125 @@ describe('LlmService', () => {
       name: 'x', type: 'openai', model: 'gpt-4', tier: 'warp-speed',
     })).rejects.toThrow();
   });
+
+  // ── Auth verification at registration time ────────────────────────────
+  // Catches misconfigured tokens / wrong URLs at create/update, not at
+  // first chat. The actual upstream-probe logic lives in each adapter's
+  // verifyAuth(); these tests exercise the service's reaction to the
+  // probe result.
+
+  it('create: throws LlmAuthVerificationError when adapter probe returns reason=auth', async () => {
+    const repo = mockRepo();
+    const sec = makeSecret({ id: 'sec-bad', name: 'bad-key' });
+    const secrets = mockSecrets({ 'bad-key': sec }, { token: 'sk-bad' });
+    const adapters = {
+      get: vi.fn(() => ({
+        kind: 'openai',
+        verifyAuth: vi.fn(async () => ({ ok: false, reason: 'auth', status: 401, body: '{"error":"invalid_api_key"}' })),
+      })),
+    } as unknown as Parameters<typeof LlmService>[2]['adapters'];
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const svc = new LlmService(repo, secrets as any, { adapters });
+    await expect(svc.create({
+      name: 'wrong-key', type: 'openai', model: 'gpt-4o',
+      apiKeyRef: { name: 'bad-key', key: 'token' },
+    })).rejects.toThrow(LlmAuthVerificationError);
+    // Repo.create should NOT have been called — no row written.
+    expect(repo.create).not.toHaveBeenCalled();
+  });
+
+  it('create: warn-only when probe returns reason=unreachable (still creates row)', async () => {
+    const repo = mockRepo();
+    const sec = makeSecret({ id: 'sec-x', name: 'k' });
+    const secrets = mockSecrets({ k: sec }, { token: 'k' });
+    const log = { warn: vi.fn() };
+    const adapters = {
+      get: vi.fn(() => ({
+        kind: 'openai',
+        verifyAuth: vi.fn(async () => ({ ok: false, reason: 'unreachable', error: 'ECONNREFUSED' })),
+      })),
+    } as unknown as Parameters<typeof LlmService>[2]['adapters'];
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const svc = new LlmService(repo, secrets as any, { adapters, log });
+    const view = await svc.create({
+      name: 'offline', type: 'openai', model: 'gpt-4o',
+      url: 'http://localhost:9999',
+      apiKeyRef: { name: 'k', key: 'token' },
+    });
+    expect(view.name).toBe('offline');
+    expect(repo.create).toHaveBeenCalledOnce();
+    expect(log.warn).toHaveBeenCalledWith(expect.stringContaining('unreachable'));
+  });
+
+  it('create: warn-only when probe returns reason=unexpected (404 from a stripped proxy)', async () => {
+    const repo = mockRepo();
+    const sec = makeSecret({ id: 'sec-x', name: 'k' });
+    const secrets = mockSecrets({ k: sec }, { token: 'k' });
+    const log = { warn: vi.fn() };
+    const adapters = {
+      get: vi.fn(() => ({
+        kind: 'openai',
+        verifyAuth: vi.fn(async () => ({ ok: false, reason: 'unexpected', status: 404, body: 'not found' })),
+      })),
+    } as unknown as Parameters<typeof LlmService>[2]['adapters'];
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const svc = new LlmService(repo, secrets as any, { adapters, log });
+    const view = await svc.create({
+      name: 'stripped-proxy', type: 'openai', model: 'gpt-4o',
+      apiKeyRef: { name: 'k', key: 'token' },
+    });
+    expect(view.name).toBe('stripped-proxy');
+    expect(log.warn).toHaveBeenCalledWith(expect.stringContaining('HTTP 404'));
+  });
+
+  it('create: skipAuthCheck=true bypasses the probe', async () => {
+    const repo = mockRepo();
+    const sec = makeSecret({ id: 'sec-x', name: 'k' });
+    const secrets = mockSecrets({ k: sec }, { token: 'k' });
+    const verifyAuth = vi.fn(async () => ({ ok: false, reason: 'auth', status: 401, body: 'no' }));
+    const adapters = {
+      get: vi.fn(() => ({ kind: 'openai', verifyAuth })),
+    } as unknown as Parameters<typeof LlmService>[2]['adapters'];
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const svc = new LlmService(repo, secrets as any, { adapters });
+    const view = await svc.create({
+      name: 'offline-staging', type: 'openai', model: 'gpt-4o',
+      apiKeyRef: { name: 'k', key: 'token' },
+    }, { skipAuthCheck: true });
+    expect(view.name).toBe('offline-staging');
+    expect(verifyAuth).not.toHaveBeenCalled();
+  });
+
+  it('create: probe is skipped when no apiKeyRef (nothing to verify)', async () => {
+    const repo = mockRepo();
+    const verifyAuth = vi.fn();
+    const adapters = {
+      get: vi.fn(() => ({ kind: 'openai', verifyAuth })),
+    } as unknown as Parameters<typeof LlmService>[2]['adapters'];
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const svc = new LlmService(repo, mockSecrets({}) as any, { adapters });
+    await svc.create({ name: 'no-key', type: 'ollama', model: 'llama3', url: 'http://localhost:11434' });
+    expect(verifyAuth).not.toHaveBeenCalled();
+  });
+
+  it('update: probes only when apiKeyRef or url changes', async () => {
+    const existing = makeLlm({ id: 'llm-up', name: 'up', apiKeySecretId: 'sec-x', apiKeySecretKey: 'token' });
+    const repo = mockRepo([existing]);
+    const sec = makeSecret({ id: 'sec-x', name: 'k' });
+    const secrets = mockSecrets({ k: sec }, { token: 'k' });
+    const verifyAuth = vi.fn(async () => ({ ok: true }));
+    const adapters = {
+      get: vi.fn(() => ({ kind: 'openai', verifyAuth })),
+    } as unknown as Parameters<typeof LlmService>[2]['adapters'];
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const svc = new LlmService(repo, secrets as any, { adapters });
+
+    // Description-only update — no probe.
+    await svc.update('llm-up', { description: 'new' });
+    expect(verifyAuth).not.toHaveBeenCalled();
+
+    // URL change — probe runs.
+    await svc.update('llm-up', { url: 'http://new-host:4000' });
+    expect(verifyAuth).toHaveBeenCalledOnce();
+  });
 });