Nansen Web Fetcher

Fetch and analyze content from one or more URLs using AI (Gemini 2.5 Flash). Use when you have specific URLs and need to extract or summarize their content....

Security Scan

The skill is internally coherent: it declares the nansen CLI and a NANSEN_API_KEY, its instructions only call that CLI to fetch/analyze URLs, and its npm install is proportionate to the task.

Purpose & Capability

Name and description (fetch and analyze web URLs) match the declared requirements: the nansen binary and NANSEN_API_KEY are exactly what the nansen CLI would need to perform web fetches and AI analysis.

Instruction Scope

SKILL.md instructs only running the nansen CLI (nansen web fetch ...) against user-supplied URLs and asking a question. It does not instruct reading unrelated files, accessing other env vars, or posting data to unexpected endpoints.

Install Mechanism

Install uses a public package manager (node/npm) installing package 'nansen-cli' which produces the nansen binary — this is expected for a CLI-based skill. This is moderate-risk compared with instruction-only skills because it writes a binary to disk; verify the npm package's authenticity and maintainers before installing.

Credentials

Only NANSEN_API_KEY is required and declared as the primary credential, which is proportionate for a service-backed fetch-and-analyze tool. No additional secrets or unrelated env vars are requested.

Persistence & Privilege

always is false and the skill does not request system-wide config changes or access to other skills' credentials. Default autonomous invocation is allowed (platform normal) and not combined with other high-risk flags.

Assessment

This skill appears to do exactly what it says: run the nansen CLI against URLs using your NANSEN_API_KEY. Before installing, verify the npm package 'nansen-cli' is the official/expected package (check the package owner, repo URL, and recent versions), consider installing in a controlled environment, and ensure the API key you provide has appropriate scope and billing controls (rotate the key after testing). If you are unsure about the npm package's provenance, inspect its source repository and published files (or run it in a sandbox) before granting your production API key.

Web Fetch

Fetch and analyze content from one or more URLs using Gemini 2.5 Flash with URL context.

nansen web fetch https://nansen.ai --question "What products does Nansen offer?"
nansen web fetch --url https://example.com --url https://other.com --question "Compare these two sites"
nansen web fetch https://docs.uniswap.org/contracts/v4/overview --question "What changed in v4?"

Positional args and --url flags can be combined — all become URLs to fetch.

Flag	Values	Default	Purpose
--url	URL	—	URL to fetch (repeatable for multiple URLs, up to 20)
--question	string	required	Question to answer about the URL content
--pretty	flag	off	Human-readable JSON

Returns:

• analysis — AI-generated answer to your question
• retrieved_urls — URLs successfully fetched
• failed_urls — URLs that could not be retrieved

Tip: Combine with web search — search first to find relevant URLs, then fetch to get full content.

# Find and analyze in two steps
nansen web search "uniswap v4 launch" --num-results 3 --fields link
nansen web fetch https://blog.uniswap.org/... --question "What are the key changes?"

Note: 30s timeout. Paywalled or bot-blocked pages may appear in failed_urls.