dev.agentsim/mcp
REMOTE · MCP.AGENTSIM.DEV · SCANNED OCT 6
Control plane for agent auth walls. Connector 0 handles SMS OTP with US test numbers.
Available components
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security83
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- The endpoint enforces authorisation, but returns a challenge with no valid RFC 9728 metadata, so a client cannot discover where to get a token. See how to fix → View diagnostics → Fail
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability0
- Transport blocked by authentication: the endpoint requires auth we don't have to verify streamable-http. See how to fix → View diagnostics → Unverified
Schema Quality & AI Usability0
- Schema blocked by authentication: the endpoint requires auth we don't have to read it. See how to fix → Unverified
Stability & Change Management0
- Stability not yet verified: not enough scan history yet (needs a 30-day window).Unverified
Tool Coverage0
- Tool coverage blocked by authentication: the endpoint requires auth we don't have to read its tools.Unverified
Tool Safety0
- Tool safety blocked by authentication: the endpoint requires auth we don't have to read its tools.Unverified
Capabilities0
- Capabilities blocked by authentication: the endpoint requires auth we don't have to read them. See how to fix → Unverified
Unverified: 6 categories
Categories scored 0 because we could not verify them: authentication we do not have, an unreachable endpoint, or not enough scan history. We only credit what we can confirm. Claim this server and supply a read-only token to verify it and lift the score.
How do I install the dev.agentsim/mcp server?
dev.agentsim/mcp is a hosted endpoint at https://mcp.agentsim.dev/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · mcp.agentsim.dev
claude mcp add --transport http dev-agentsim-mcp 'https://mcp.agentsim.dev/mcp'
{
"mcpServers": {
"dev-agentsim-mcp": {
"url": "https://mcp.agentsim.dev/mcp"
}
}
} {
"servers": {
"dev-agentsim-mcp": {
"type": "http",
"url": "https://mcp.agentsim.dev/mcp"
}
}
} [mcp_servers.dev-agentsim-mcp] url = "https://mcp.agentsim.dev/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"dev-agentsim-mcp": {
"type": "remote",
"url": "https://mcp.agentsim.dev/mcp",
"enabled": true
}
}
} openclaw mcp add dev-agentsim-mcp --url 'https://mcp.agentsim.dev/mcp' --transport streamable-http
mcp_servers:
dev-agentsim-mcp:
url: "https://mcp.agentsim.dev/mcp" {
"McpServers": {
"dev-agentsim-mcp": {
"Transport": "http",
"Url": "https://mcp.agentsim.dev/mcp"
}
}
} assistant mcp add dev-agentsim-mcp -t streamable-http -u 'https://mcp.agentsim.dev/mcp'
{
"mcpServers": {
"dev-agentsim-mcp": {
"type": "http",
"url": "https://mcp.agentsim.dev/mcp"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 28 Sept 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 25 Sept 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 8 Sept 26 −44
- Endpoint reachability: reachable → behind authorisation ▼ security
- Authorization: unverified → fail ▼ security
- Stability: pass → unverified ▼ security
- Tool safety: pass → unverified ▼ security
- Transport: pass → unverified ▼ security
- Capabilities: pass → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- Schema quality: 100 → unverified ▼ functional
- 27 Aug 26 0
- The server rewrote its instructions, which are the text every model session reads security
- Tool “get_messages” rewrote its description, which is the text the model reads security
- Tool “list_numbers” rewrote its description, which is the text the model reads security
- Tool “provision_number” rewrote its description, which is the text the model reads security
- Tool “release_number” rewrote its description, which is the text the model reads security
- Tool “wait_for_otp” rewrote its description, which is the text the model reads security
- Schema quality: 84 → 106 ▼ functional
- New tool “open_challenge” functional
- New tool “wait_for_verdict” functional
- 26 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 25 Aug 26 0
- Stability: 0.97 → pass security
- 11 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 7 Aug 26 0
- The server no longer declares the “experimental” capability functional
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 6 Oct 2026 · Probed https://mcp.agentsim.dev/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=mcp.agentsim.dev | CN=YR2,O=Let's Encrypt,C=US | 14 Sept 2026 | 13 Dec 2026 | RSA 2048 | SHA256-RSA | 50e4f56979f19f3c5624f5ea54ae5670644 |
| SANs: mcp.agentsim.dev | ||||||
| CN=YR2,O=Let's Encrypt,C=US (CA) | CN=Root YR,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | RSA 2048 | SHA256-RSA | 4ebd24947e24d394802d84a52fd5b319 |
| CN=Root YR,O=ISRG,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | RSA 4096 | SHA256-RSA | f24b6d17f9d9ad7cb1c9fea78782699f |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of mcp.agentsim.dev. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| dev. | present | 60074 | 8 | Verified |
| agentsim.dev. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication Challenged, unverified
The endpoint asked for a token, but we could not retrieve and validate the RFC 9728 metadata that tells a client how to obtain one.
| Result | Challenged, unverified |
|---|---|
| Enforced | On connection |
| HTTP status | 401 |
Protected resource metadata
| Retrieved | No |
|---|---|
| Problem | no_resource_metadata |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://mcp.agentsim.dev/mcp | Auth required | 401 | |
| http (plaintext) | http://mcp.agentsim.dev/mcp | HTTPS enforced | 301 | https://mcp.agentsim.dev/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
get_messages ~56
List all SMS messages received in this session without consuming the OTP. Use this to inspect raw messages or check if an SMS arrived before calling wait_for_verdict. Does NOT mark the OTP as consumed.
| Name | Type | Req | Description |
|---|---|---|---|
| input | object | yes | – |
Structured output declared, but exposes no named fields.
No examples provided.
list_numbers ~39
List active challenge sessions, optionally filtered by agent_id. Use this to check for leaked sessions or inspect what is currently active.
| Name | Type | Req | Description |
|---|---|---|---|
| agent_id | – | – | – |
Structured output declared, but exposes no named fields.
No examples provided.
open_challenge ~120
Open an authentication challenge session. Supports multiple channels: sms_otp (programmable US number), email_otp (mock inbox), magic_link (mock inbox), and webauthn_required (detect-and-halt). Returns the challenge identifier (phone number or email address) and a session_id needed for all subsequent calls. The session is reserved for ttl_seconds. Next step: use the returned identifier on your target service to trigger the challenge, then call `wait_for_verdict` with the returned `session_id`.
| Name | Type | Req | Description |
|---|---|---|---|
| input | object | yes | – |
Structured output declared, but exposes no named fields.
No examples provided.
provision_number ~138
Open an SMS challenge session (alias for open_challenge with channel=sms_otp). DEPRECATED: Use `open_challenge` with channel="sms_otp" instead. This tool is kept for backward compatibility with existing MCP clients. Returns the phone number (e164 format) and a session_id needed for all subsequent calls. The session is reserved for ttl_seconds. Next step: use the returned `number` on an app you own to trigger the wall, then call `wait_for_verdict` (or the `wait_for_otp` alias) with the `session_id`.
| Name | Type | Req | Description |
|---|---|---|---|
| input | object | yes | – |
Structured output declared, but exposes no named fields.
No examples provided.
release_number ~43
Close a challenge session. Always call this when you are done — even on error — so the session does not keep consuming pool capacity.
| Name | Type | Req | Description |
|---|---|---|---|
| input | object | yes | – |
Structured output declared, but exposes no named fields.
No examples provided.
wait_for_otp ~116
Block until an SMS verdict arrives for this session (alias for wait_for_verdict). DEPRECATED: Use `wait_for_verdict` instead. This tool is kept for backward compatibility with existing MCP clients. Polls the AgentSIM API for up to `timeout_seconds`. Returns the OTP code when the SMS challenge resolves. If the verdict does not arrive in time, raises a ToolError with advice on retrying. Always call `release_number` after you have used the verdict.
| Name | Type | Req | Description |
|---|---|---|---|
| input | object | yes | – |
Structured output declared, but exposes no named fields.
No examples provided.
wait_for_verdict ~129
Block until a challenge verdict arrives for this session. Polls the AgentSIM API for up to `timeout_seconds`. Returns the structured verdict, which may include: - otp_code: the parsed OTP (for sms_otp, email_otp channels) - magic_link: the extracted HTTPS URL (for magic_link channel) - webauthn_required: true if WebAuthn/passkey was detected (detect-and-halt) - policy_denied: true if the service_url is blocked by account policy Always call `release_number` after processing the verdict.
| Name | Type | Req | Description |
|---|---|---|---|
| input | object | yes | – |
Structured output declared, but exposes no named fields.
No examples provided.
What is the dev.agentsim/mcp server?
dev.agentsim/mcp is listed in the public MCP registry as dev.agentsim/mcp. Control plane for agent auth walls. Connector 0 handles SMS OTP with US test numbers. This page covers its hosted endpoint (https://mcp.agentsim.dev/mcp).
Is the dev.agentsim/mcp server safe to use?
dev.agentsim/mcp scores 33 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the dev.agentsim/mcp server expose?
dev.agentsim/mcp exposes 7 tools: open_challenge, provision_number, wait_for_verdict, wait_for_otp, get_messages, and 2 more. Their descriptions and schemas cost roughly 641 tokens of context every time the server is loaded.
Does the dev.agentsim/mcp server require authentication?
Yes. dev.agentsim/mcp asked us for credentials when we connected, so you will need to authorise it in your MCP client before it can do anything.
Is the dev.agentsim/mcp server still maintained?
dev.agentsim/mcp is still listed as active in the MCP registry. We last reached this channel on 6 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.