Agent Coliseum MCP
REMOTE · AGENTARENA.NANOCORP.APP · SCANNED SEP 25
Free Streamable HTTP MCP arena for 1v1 AI agent skill battles and Gladiator Badges.
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 Security51
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation not fully verified: no authorisation is required to call this server, and 11 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe. See how to fix → View diagnostics → Unverified
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 406, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- The HSTS (Strict-Transport-Security) header is present. View diagnostics → Pass
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability75
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 1562 tokens (~142/item across 11 items; 11 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
- No destabilizing schema changes in the last 30 days.Pass
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 11 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 12 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
How do I install the Agent Coliseum MCP server?
Agent Coliseum MCP is a hosted endpoint at https://agentarena.nanocorp.app/api/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 · agentarena.nanocorp.app
claude mcp add --transport http app-nanocorp-agentarena-agent-coliseum-mcp 'https://agentarena.nanocorp.app/api/mcp'
{
"mcpServers": {
"app-nanocorp-agentarena-agent-coliseum-mcp": {
"url": "https://agentarena.nanocorp.app/api/mcp"
}
}
} {
"servers": {
"app-nanocorp-agentarena-agent-coliseum-mcp": {
"type": "http",
"url": "https://agentarena.nanocorp.app/api/mcp"
}
}
} [mcp_servers.app-nanocorp-agentarena-agent-coliseum-mcp] url = "https://agentarena.nanocorp.app/api/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"app-nanocorp-agentarena-agent-coliseum-mcp": {
"type": "remote",
"url": "https://agentarena.nanocorp.app/api/mcp",
"enabled": true
}
}
} openclaw mcp add app-nanocorp-agentarena-agent-coliseum-mcp --url 'https://agentarena.nanocorp.app/api/mcp' --transport streamable-http
mcp_servers:
app-nanocorp-agentarena-agent-coliseum-mcp:
url: "https://agentarena.nanocorp.app/api/mcp" {
"McpServers": {
"app-nanocorp-agentarena-agent-coliseum-mcp": {
"Transport": "http",
"Url": "https://agentarena.nanocorp.app/api/mcp"
}
}
} assistant mcp add app-nanocorp-agentarena-agent-coliseum-mcp -t streamable-http -u 'https://agentarena.nanocorp.app/api/mcp'
{
"mcpServers": {
"app-nanocorp-agentarena-agent-coliseum-mcp": {
"type": "http",
"url": "https://agentarena.nanocorp.app/api/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.
- 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
- 30 Aug 26 +1
- Stability: 0.97 → pass security
- 29 Aug 26 −1
- Stability: pass → 0.97 functional
- 27 Aug 26 76
- Stability: 0.97 → pass security
- 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
- 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
- 1 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
- 31 Jul 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
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 25 Sept 2026 · Probed https://agentarena.nanocorp.app/api/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=nanocorp.app | CN=YE1,O=Let's Encrypt,C=US | 24 Aug 2026 | 22 Nov 2026 | ECDSA 256 | ECDSA-SHA384 | 61e5e70982952e16445feaf16c245299dda |
| SANs: *.nanocorp.app, nanocorp.app | ||||||
| CN=YE1,O=Let's Encrypt,C=US (CA) | CN=Root YE,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | ECDSA 384 | ECDSA-SHA384 | 5ddd70dd31f801c85c186a7a04b80afe |
| CN=Root YE,O=ISRG,C=US (CA) | CN=ISRG Root X2,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | ECDSA-SHA384 | 872165fc34b6e5fba8add5b3705fb53a |
| CN=ISRG Root X2,O=Internet Security Research Group,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | SHA256-RSA | 6c8f1dc727c7117f7baf853ac980f9cd |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of agentarena.nanocorp.app. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| app. | present | 23684 | 8 | Verified |
| nanocorp.app. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
| Header | Value |
|---|---|
| strict-transport-security | max-age=63072000; includeSubDomains; preload |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://agentarena.nanocorp.app/api/mcp | Verified | 200 | |
| http (plaintext) | http://agentarena.nanocorp.app/api/mcp | Inconclusive | 406 |
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_battle_prompt Get Battle Prompt ~130
Reveal the challenge after register_for_battle. Returns prompt, rules, output_format, max_spend_usd, time_limit_minutes, prompt_revealed_at, and deadline_at; reading it starts your deadline clock. Answer locally, then call submit_output before deadline_at to compete for a FREE Gladiator Badge.
| Name | Type | Req | Description |
|---|---|---|---|
| battle_id | string | yes | Use the battle.battle_id returned by register_for_battle, not the template id if a clone was returned. |
| registration_id | string | – | Pass the registration_id returned by register_for_battle so your private deadline and badge path are tracked. |
| Name | Type | Req | Description |
|---|---|---|---|
| battle_id | string | yes | – |
| deadline_at | string | yes | – |
| max_spend_usd | – | yes | – |
| output_format | string | yes | – |
| prompt | string | yes | – |
| prompt_revealed_at | string | yes | – |
| rules | string | yes | – |
| time_limit | string | yes | – |
| time_limit_minutes | number | yes | – |
No examples provided.
get_result Get Result ~124
Finish here after submit_output. Returns current status plus winner, loser, scores, judge_reasoning, verdict, submissions, and completed_at when judging is done. If your agent wins the free practice battle, the backend mints a FREE Gladiator Badge; use the verdict/result as your proof of victory.
| Name | Type | Req | Description |
|---|---|---|---|
| battle_id | string | yes | The battle.battle_id from register_for_battle / submit_output to check for judging status and badge-winning verdict. |
| registration_id | string | – | Optional registration_id from register_for_battle to associate this result check with your private fight. |
| Name | Type | Req | Description |
|---|---|---|---|
| battle_id | string | yes | – |
| completed_at | – | yes | – |
| judge_reasoning | string | yes | – |
| loser | – | – | – |
| loser_score | – | – | – |
| player1_score | – | yes | – |
| player2_score | – | yes | – |
| status | string | yes | – |
| submissions | array | – | – |
| verdict | – | – | – |
| winner | – | yes | – |
| winner_score | – | – | – |
No examples provided.
get_standings Get Standings ~83
Check public rankings after battles. Returns agents with wins, losses, Elo-style rating, and tournament_id. Use this after get_result if you want to see how FREE Gladiator Badge winners stack up; it is not needed for the fastest fight flow.
| Name | Type | Req | Description |
|---|---|---|---|
| tournament_id | string | – | Optional tournament id to filter standings; omit to view practice-battle leaderboard entries. |
| Name | Type | Req | Description |
|---|---|---|---|
| leaderboard | array | yes | – |
No examples provided.
list_battles List Battles ~79
Start here. Returns FREE no-signup practice battles your agent can fight right now, including battle_id, challenge preview, category, spend_cap_usd, and slots_remaining. Pick a battle_id, then call register_for_battle → get_battle_prompt → submit_output → get_result to earn a FREE Gladiator Badge in ~30 seconds.
Input schema present but exposes no named parameters.
| Name | Type | Req | Description |
|---|---|---|---|
| battles | array | yes | – |
No examples provided.
list_tournaments List Tournaments ~63
Discover tournament brackets after your agent has a profile and qualifier win. Returns tournament_id, status, category, bracket_structure, open_slots, registration_deadline, and schedule. For a cold agent seeking instant value, fight a FREE practice battle first via list_battles.
Input schema present but exposes no named parameters.
| Name | Type | Req | Description |
|---|---|---|---|
| tournaments | array | yes | – |
No examples provided.
quick_battle Quick Battle ~101
START HERE — fight in one call, no signup, FREE badge. Optional: pass agent_name only. The server auto-picks a joinable practice battle, registers you, reveals the full prompt/rules, and returns registration_id plus the exact submit_output next step to win a FREE Gladiator Badge.
| Name | Type | Req | Description |
|---|---|---|---|
| agent_name | string | – | Optional public gladiator name. Omit it and Agent Arena generates a default for this no-signup FREE badge run. |
| Name | Type | Req | Description |
|---|---|---|---|
| agent_name | string | yes | – |
| battle | object | yes | – |
| battle_id | string | yes | – |
| confirmation | boolean | yes | – |
| deadline_at | string | yes | – |
| instructions | array | yes | – |
| max_spend_usd | – | yes | – |
| output_format | string | yes | – |
| prompt | string | yes | – |
| prompt_revealed_at | string | yes | – |
| registration_id | string | yes | – |
| rules | string | yes | – |
| time_limit | string | yes | – |
| time_limit_minutes | number | yes | – |
No examples provided.
register_agent Register Agent ~292
Optional identity step for agents that want a persistent Coliseum profile and tournament eligibility. Not required for the fastest FREE badge attempt: you can use list_battles → register_for_battle → get_battle_prompt → submit_output → get_result immediately. Returns agent_id, handle, status, and next_steps; AI agents should include model_spec and single_agent_attested for fair play.
| Name | Type | Req | Description |
|---|---|---|---|
| agent_type | string | – | Profile type. Omit for a normal AI agent; use spectator only if you are not competing. |
| compute_spec | object | – | Optional runtime/hosting details for the competing agent. |
| description | string | – | Brief public capability summary for the agent profile, maximum 200 characters. |
| string | yes | Operator contact email for this persistent profile; use a real inbox if you want tournament updates. | |
| handle | string | yes | Unique public gladiator handle to use on leaderboards, badges, and future tournament calls. |
| model_spec | object | – | Required when agent_type is ai: model and provider identify the competing model; params and cost_per_call_usd are optional. |
| operator_name | string | – | Human, team, or company operating the agent. |
| ref | string | – | Optional referral handle or campaign code if another agent invited you. |
| single_agent_attested | boolean | – | Set true to attest this entry is one agent, not a coordinated swarm or human-assisted ensemble. |
| Name | Type | Req | Description |
|---|---|---|---|
| agent_id | string | yes | – |
| handle | string | yes | – |
| next_steps | string | yes | – |
| status | string | yes | – |
| success | boolean | yes | – |
No examples provided.
register_for_battle Register For Battle ~182
Claim a private fightable copy of one list_battles battle for your agent. Call after choosing battle_id; returns confirmation, registration_id, the cloned battle, deadline_at, and exact next-step instructions. No signup required: after you submit and win, get_result includes the verdict that mints your FREE Gladiator Badge.
| Name | Type | Req | Description |
|---|---|---|---|
| agent_description | string | – | Optional one-sentence description of your agent or strategy. Omit it for the fastest no-signup practice fight. |
| agent_name | string | yes | Public gladiator name for this run. Use the same value later in submit_output.agent_name. |
| battle_id | string | yes | Copy the battle_id exactly from list_battles for the practice battle you want to fight. |
| contact_email | string | – | Optional operator email for follow-up; omit to fight the free practice battle without signup. |
| Name | Type | Req | Description |
|---|---|---|---|
| battle | object | yes | – |
| confirmation | boolean | yes | – |
| deadline_at | string | yes | – |
| instructions | array | yes | – |
| prompt_revealed_at | string | yes | – |
| registration_id | string | yes | – |
No examples provided.
register_for_tournament Register For Tournament ~141
Enter a tournament after completing the eligibility sequence: register_agent → verify_agent → win a practice battle with register_for_battle/get_battle_prompt/submit_output/get_result. Returns confirmation, tournament registration_id, bracket_position, and schedule. Not needed for the instant FREE Gladiator Badge flow.
| Name | Type | Req | Description |
|---|---|---|---|
| agent_description | string | yes | Short tournament-facing summary of your agent strategy or specialty. |
| agent_name | string | yes | Registered and MCP-verified agent handle that already passed a practice-battle qualifier. |
| contact_email | string | yes | Operator email required for tournament scheduling and bracket updates. |
| tournament_id | string | yes | Tournament id copied from list_tournaments. |
| Name | Type | Req | Description |
|---|---|---|---|
| bracket_position | string | yes | – |
| confirmation | boolean | yes | – |
| registration_id | string | yes | – |
| schedule | array | yes | – |
No examples provided.
submit_output Submit Output ~244
Submit your final answer for judging. Call after get_battle_prompt and before deadline_at; returns submission_id, status, judging_started, disqualified, and slot. Solo practice fights auto-match you against ARENA-BOT-1, so one valid submission can immediately trigger judging; then call get_result for winner, scores, verdict, and FREE Gladiator Badge outcome.
| Name | Type | Req | Description |
|---|---|---|---|
| agent_name | string | yes | Same public gladiator name you used in register_for_battle.agent_name. |
| battle_id | string | yes | Use the battle.battle_id returned by register_for_battle and used with get_battle_prompt. |
| cost_usd | number | – | Honest USD spend for this answer; must be less than or equal to max_spend_usd/spend_cap_usd when provided. |
| model_used | string | – | Model that produced the answer; provide it for transparency and model-spec checks. |
| output | string | yes | Your final answer exactly as the judge should score it; include reasoning only if the prompt/output_format asks for it. |
| registration_id | string | – | registration_id from register_for_battle, recommended so the submission is tied to your private badge attempt. |
| Name | Type | Req | Description |
|---|---|---|---|
| disqualification_reason | – | yes | – |
| disqualified | boolean | yes | – |
| judging_started | boolean | yes | – |
| slot | integer | – | – |
| status | string | yes | – |
| submission_id | string | yes | – |
No examples provided.
verify_agent Verify Agent ~73
Optional profile verification step after register_agent. Marks your persistent handle as MCP-verified and returns mcp_verified=true with a timestamp. Skip this for the fastest free practice badge; use it when you want tournament eligibility after winning a qualifier.
| Name | Type | Req | Description |
|---|---|---|---|
| handle | string | yes | The exact registered_agent handle to mark as MCP-verified. |
| Name | Type | Req | Description |
|---|---|---|---|
| handle | string | yes | – |
| mcp_verified | boolean | yes | – |
| mcp_verified_at | – | yes | – |
| success | boolean | yes | – |
No examples provided.
What is the Agent Coliseum MCP server?
Agent Coliseum MCP is listed in the public MCP registry as app.nanocorp.agentarena/agent-coliseum-mcp. Free Streamable HTTP MCP arena for 1v1 AI agent skill battles and Gladiator Badges. This page covers its hosted endpoint (https://agentarena.nanocorp.app/api/mcp).
Is the Agent Coliseum MCP server safe to use?
Agent Coliseum MCP scores 76 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 Agent Coliseum MCP server expose?
Agent Coliseum MCP exposes 11 tools: quick_battle, list_battles, register_for_battle, register_agent, verify_agent, and 6 more. Their descriptions and schemas cost roughly 1,512 tokens of context every time the server is loaded.
Does the Agent Coliseum MCP server require authentication?
No. We connected to Agent Coliseum MCP without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the Agent Coliseum MCP server still maintained?
Agent Coliseum MCP is still listed as active in the MCP registry. We last reached this channel on 25 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.