Codeforces MCP Server
REMOTE · CODEFORCES-OJ-MCP.LANTANGTANG54.WORKERS.DEV · SCANNED AUG 3
Search Codeforces problems and inspect public problem metadata through the official Codeforces API.
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 →
Endpoint Security63
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one. See how to fix → View diagnostics → Partial
- HTTPS not yet verified: we couldn't determine whether a plaintext access path exists. View diagnostics → Unverified
- 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 & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability43
- AI-judged instruction clarity (poor).Fail
- Tool/resource definitions use about 138 tokens (~34/item across 4 items; 4 tools + 0 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management27
- Stability observed for 8 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage71
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 0% of tool parameters carry a description.Fail
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Add this component to your MCP client. Where a client-specific snippet is available, pick your client below and copy it straight into your config; otherwise use the connection detail shown.
remote · codeforces-oj-mcp.lantangtang54.workers.dev
claude mcp add --transport http ketherworks-codeforces https://codeforces-oj-mcp.lantangtang54.workers.dev/mcp
[mcp_servers.ketherworks-codeforces] url = "https://codeforces-oj-mcp.lantangtang54.workers.dev/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"ketherworks-codeforces": {
"type": "remote",
"url": "https://codeforces-oj-mcp.lantangtang54.workers.dev/mcp",
"enabled": true
}
}
} openclaw mcp add ketherworks-codeforces --url https://codeforces-oj-mcp.lantangtang54.workers.dev/mcp --transport streamable-http
mcp_servers:
ketherworks-codeforces:
url: "https://codeforces-oj-mcp.lantangtang54.workers.dev/mcp" {
"mcpServers": {
"ketherworks-codeforces": {
"type": "http",
"url": "https://codeforces-oj-mcp.lantangtang54.workers.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.
- 3 Aug 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.
- 1 Aug 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.
- 31 Jul 26 +3
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 30 Jul 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 10 to 13. That category is still filling its 30-day observation window: 3 days of observed history at the previous scan, 4 at this one. The score rises as the window fills, whether or not the server changes.
- 28 Jul 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.
- 27 Jul 26 +1
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 26 Jul 26 52
First indexed and scored.
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 3 Aug 2026 · Probed https://codeforces-oj-mcp.lantangtang54.workers.dev/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=lantangtang54.workers.dev | CN=YE1,O=Let's Encrypt,C=US | 16 Jun 2026 | 14 Sept 2026 | ECDSA 256 | ECDSA-SHA384 | 651f3c34c4031e514c9d7315e19b1bd5b47 |
| SANs: *.lantangtang54.workers.dev, lantangtang54.workers.dev | ||||||
| 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 |
DNSSEC insecure
Validation of codeforces-oj-mcp.lantangtang54.workers.dev. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| dev. | present | 60074 | 8 | Verified |
| workers.dev. | 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 |
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://codeforces-oj-mcp.lantangtang54.workers.dev/mcp | Verified | 200 | |
| http (plaintext) | http://codeforces-oj-mcp.lantangtang54.workers.dev/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.
codeforces_get_problem_metadata Get Codeforces Problem Metadata ~36
Get official metadata only. This tool does not return a problem statement or submit code.
| Name | Type | Req | Description |
|---|---|---|---|
| nativeId | string | yes | — |
Structured output declared, but exposes no named fields.
No examples provided.
oj_capabilities Codeforces Provider Capabilities ~20
Report audited Codeforces official API capabilities and unsupported operations.
Input schema present but exposes no named parameters.
Structured output declared, but exposes no named fields.
No examples provided.
oj_health Codeforces Provider Health ~21
Return passive transport, schema, and persisted Codeforces upstream health.
Input schema present but exposes no named parameters.
Structured output declared, but exposes no named fields.
No examples provided.
oj_search_problems Search Codeforces Problems ~61
Search official Codeforces problem metadata by id, title, or tag.
| Name | Type | Req | Description |
|---|---|---|---|
| limit | integer | yes | — |
| platform | string | yes | — |
| query | string | yes | — |
| requestId | string | yes | — |
| schemaVersion | string | yes | — |
Structured output declared, but exposes no named fields.
No examples provided.