Best fit today
Primary use case
Browser-Agent OTP QA
Run browser agents through SMS OTP steps with a temporary number, parsed code, and a clear outcome when the target never sends.
View browser-agent QAConnector 0 · SMS OTP for agent runs
The Control Plane For Real-World Auth Walls
AgentSIM is the control plane for agents hitting the real world's auth walls. SMS OTP is the first challenge type.
10 free sessions/month. No card required. Then $0.99 per session.
Connector 0 uses synthetic or programmable US test numbers. Best fit: owned auth, CI/QA, and verified-compatible services.
verification-run.ts
Session
sess_7K4P9A
TTL
15 min
Result
session.created
01const session = await agentsim.provision({02 country: "US",03 serviceUrl: "https://staging.example.com/login"04});05await browser.fill("input[name='phone']", session.number);06const otp = await session.waitForOtp({ timeout: 30_000 });07await browser.fill("input[name='otp']", otp.otpCode);08await session.release();
Returned result
active{"session_id": "sess_7K4P9A","number": "+1 202 555 0142","country": "US","expires_in": 900}
Use Cases
Connector 0 handles SMS OTP auth walls
SMS OTP is the first challenge type. It is best for authorized browser-agent QA, staging auth, and delivery diagnostics. Treat destination support as empirical.
Authorized flows
Controlled testing
Owned auth flows
Exercise Supabase, Auth0, Firebase, Clerk, or custom staging auth flows where your team controls the sender and test account.
Read integration guideCore product
When no code arrives
No-SMS diagnostics
Classify each run as OTP received, SMS without OTP, no SMS, phone rejected, or anti-bot gated instead of waiting blindly.
Debug no SMSIntegrates With
Call OTP sessions three ways.
Give an agent a phone tool through MCP, call OTP sessions from browser automation, or send results back to your system with webhooks.
MCP
Give coding agents a phone tool
Expose provision and wait-for-OTP actions to Claude Code, Cursor, Windsurf, and other MCP-aware clients.
agentsim.wait_for_otpSDK
Call it inside browser automation
Provision from Playwright, Puppeteer, or an agent runner, then branch on the API result.
await session.waitForOtp()Webhook
Route outcomes back to your system
Receive code, rejection, gate, and timeout events in CI, QA, or owned auth flows.
event: otp.receivedClaude CodeMCP
CursorCoding agent
WindsurfCoding agent
LangChainFramework
LlamaIndexFramework
Vercel AI SDKAI SDK
OpenAI AgentsAgents SDK
CrewAIFramework
The logo row shows places AgentSIM can fit. It does not mean every OTP destination accepts programmable numbers.
View MCP DocsThe Old Way Breaks
Phone Gates Can Fail Before SMS Exists
When a target blocks the number before sending SMS, your agent should not just wait. AgentSIM turns the attempt into a clear result: received, timed out, rejected, or gated.
receivedtimed outrejectedgated
Cloud Phone APIs
Twilio, Telnyx, Vonage
Great for messages you send. Verification gates may reject the number class before SMS.
Public SMS Inboxes
Shared virtual inboxes
Fast for manual checks, risky for automation because recycled numbers inherit reputation.
Dedicated Rentals
Persistent dedicated numbers
Right for account recovery. Overkill for short CI and QA runs.
The Mechanism
Every OTP attempt returns a usable result.
Open a session when the run hits SMS. AgentSIM waits, parses, records failure states, and releases the number when the run is done.
Provision Request
session TTL: 15 minPOST /v1/sessions{"agent_id": "browser-agent-42","country": "US","capabilities": ["sms"]}200 OK{"number": "+1 202 555 0142","country": "US","expires_in": 900}
Reserved for one run.Expires automatically.Labels the target service.
Compare
Choose The Right Tool For The Auth Wall
AgentSIM coordinates short agent runs through auth challenges. Connector 0 handles SMS OTP; rentals, cloud APIs, and public inboxes solve different phone-number jobs.
Choose Your Situation
| Decision Point | AgentSIM | JoltSMS | Cloud Phone APIs | Shared Virtual |
|---|---|---|---|---|
| Best Fit | Agent auth challenges, starting with SMS OTP | Persistent per-account phone identity | Programmable messaging you control | Manual one-off tests |
| Number Type | Synthetic or programmable US test number | Dedicated US number | VoIP or cloud-routed number | Recycled virtual inventory |
| Billing Shape | $0.99/session after free tier | $50/number/month | Number rental plus usage fees | Dynamic per-code pricing |
| Agent Delivery | SDKs, REST, webhooks, polling, MCP | REST, webhooks, MCP | SMS webhooks and lookup APIs | Usually inbox-first |
| OTP Payload | Parsed OTP plus raw message | Parsed OTP plus raw message | Usually raw inbound SMS | Varies by marketplace |
| Best Use Case | Controlled auth and verified-compatible OTP workflows | Long-lived per-account verification & recovery | Programmable SMS products you own | Throwaway manual checks |
Use AgentSIM when you own the OTP flow, or the target is verified-compatible, and the agent needs a result it can act on.
10 free sessions to prove delivery
Pricing
Pay For OTP Sessions, Not Idle Inventory
No monthly number inventory for short agent runs. Pay for the OTP sessions your agents actually open.
Hobby
$0forever
Build and test without a card.
- 10 sessions/month
- No card required
- SDK, REST, and MCP access
Builder
Recommended For Agent Teams$0.99per session
For teams running OTP steps in agent workflows.
- Unlimited sessions
- Parallel provisioning
- Webhook and polling delivery
- Parsed OTP payloads
- Delivery diagnostics
Enterprise
Customannual
Dedicated pools, audit controls, and controlled-auth support.
- Dedicated number pools
- Provider-specific audits
- Audit logs
- SLA support
Cost Model
10 free sessions/month
Cost Model
$0.99/session after free tier
Cost Model
No idle number inventory
Give The Next Agent Run An OTP Number
Start with 10 free sessions, no card required. Test provisioning, parsing, and outcomes before committing.
Start FreeNeed dedicated pools? Contact sales.No. Connector 0 uses synthetic or programmable US test numbers, and acceptance varies by target service. Google is verified blocked; Meta reaches SMS entry but delivery is unproven; other high-risk services may reject or gate before SMS. Check the support map before integrating against a specific platform.