endpoint-probe

endpoint-probe is a skill for Claude Code, Codex from moonlight-lupin/agent-skills. It costs 159 tokens per session (4,693 once invoked), scanned C, original, MIT.

A tool for discovering what an API or MCP server offers by probing its base URL. It can identify the interface type, authentication approach, endpoints, rate limits, cross-origin rules, and available MCP tools or resources.

In plain words
What is it for?
Use it to inspect REST, GraphQL, SOAP, JSON-RPC, HTTP MCP, or standard-input MCP services and learn their exposed surface.
Why use it?
It helps map an unfamiliar or partly documented service before building an integration or deciding how to connect to it.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Codex; mentions OpenCode.

Good fit Use it to inspect REST, GraphQL, SOAP, JSON-RPC, HTTP MCP, or standard-input MCP services and learn their exposed surface.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/moonlight-lupin/agent-skills/endpoint-probe
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add moonlight-lupin/agent-skills --skill endpoint-probe
Clone the repo
git clone --depth 1 https://github.com/moonlight-lupin/agent-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for endpoint-probe

README.md
[![agentmods](https://agentmods.dev/badge/skills/moonlight-lupin/agent-skills/endpoint-probe/github.svg)](https://agentmods.dev/skills/moonlight-lupin/agent-skills/endpoint-probe)
Your own site
<a href="https://agentmods.dev/skills/moonlight-lupin/agent-skills/endpoint-probe"><img src="https://agentmods.dev/badge/skills/moonlight-lupin/agent-skills/endpoint-probe/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for endpoint-probe

Your own site · 80×15
<a href="https://agentmods.dev/skills/moonlight-lupin/agent-skills/endpoint-probe"><img src="https://agentmods.dev/badge/skills/moonlight-lupin/agent-skills/endpoint-probe.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 159 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,693 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 2 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00159 $0.04693
Opus 5 $0.00079 $0.02346
Sonnet 5 $0.00032 $0.00939
Haiku 4.5 $0.00016 $0.00469

Measured 11d ago against content hash 8bb7742d6b76, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade C, and why

endpoint-probe scanned grade C with 2 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

The scan reads SKILL.md. This mod also ships 3 executable files (scripts/probe_api.py, tests/conftest.py, tests/test_redaction.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Cloud metadata endpointhighServer-side request forgery

One request to 169.254.169.254 can return temporary IAM credentials.

21. **SSRF protection.** The probe blocks private/internal IP ranges (RFC1918, loopback, link-local, CGNAT `100.64/10`, ULA `fc00::/7`, IPv4-mapped IPv6 like `::ffff:127.0.0.1`) and cloud metadata endpoints (`169.254.169

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

10. **Self-signed certs.** The script uses urllib which verifies certs by default. `PYTHONHTTPSVERIFY=0` does NOT affect urllib (it only affects `requests`/`httpx`). Self-signed targets are currently unsupported — use `-
research/endpoint-probe/SKILL.md · 234 lines

How it starts

The opening of the file, as written. The whole thing — 234 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Endpoint Probe

Probe a base URL to discover its API surface: type, auth, endpoints, rate limits, CORS, and server fingerprint.

When to Use

  • User gives you a base URL and asks "what API is available?" or "what endpoints does this have?"
  • You need to understand an undocumented or partially-documented API before building an integration
  • User asks "how does this API authenticate?" or "what auth does this endpoint need?"
  • You're evaluating a third-party service and need to map its API surface
  • User says "discover", "probe", "explore", or "recon" an API endpoint
  • User wants to know what tools an MCP server provides before configuring it
  • User asks "what does this MCP server offer?" or "what tools does MCP server X have?"

Don't use for:

  • Scraping HTML page content (use website-scraping)
  • QA testing of known functionality (use a QA/testing skill)
  • Configuring MCP servers (use an MCP configuration skill) — this skill discovers MCP server surfaces, it doesn't configure them
  • Monitoring an API over time (this is a one-shot discovery tool)

Workflow

1. Run the probe script

python scripts/probe_api.py <base_url> [options]

Options:

Flag Description Default
--auth TOKEN Auth token/credential none
--auth-type bearer, basic, or apikey bearer
--header "Key: Value" Custom header (repeatable) none
--timeout N Request timeout in seconds 10
--json Output raw JSON instead of formatted report off
--no-guess Skip REST resource guessing off
--api-version v1 API version prefix for resource probing none
--mcp Probe as MCP server over HTTP (StreamableHTTP) off
--mcp-stdio Probe as MCP server over stdio (launch subprocess) off
--mcp-env "KEY=value" Env var for stdio MCP server (repeatable) none
--allow-private Allow probing private/internal IP addresses off

Examples:

# Basic probe — no auth
python scripts/probe_api.py https://api.example.com

# With Bearer token
python scripts/probe_api.py https://api.example.com --auth "tok_abc123"

# With API key (sends X-API-Key header)
python scripts/probe_api.py https://api.example.com --auth "key_xyz" --auth-type apikey

# Skip resource guessing (faster, less noisy)
python scripts/probe_api.py https://api.example.com --no-guess

# JSON output for programmatic use
python scripts/probe_api.py https://api.example.com --json

Read the full file on GitHub · 234 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 11d ago First seen · 234 lines · 159 tokens per session scan C 8bb7742d6b76

Subscribe to this mod's changes

endpoint-probe is a skill published in the GitHub repository moonlight-lupin/agent-skills (60 stars, last pushed 3d ago), licensed MIT. It adds 159 tokens to every session and 4,693 once invoked, about $0.0008 per session on Opus 5. A static security scan graded it C with 2 findings (cloud metadata endpoint, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories