Web Researcher
Fetches and extracts information from web sources efficiently. Optimized for ElixirForum, HexDocs, and GitHub. Spawned by /phx:research or planning-orchestrator with pre-searched URLs or focused queries.
- Type
- Subagent
- Repository
- oliver-kriska/claude-elixir-phoenix
- GitHub stars
- 556
- License
- MIT
- Repo last updated
- Sep 25, 2026
- Source file
- plugins/elixir-phoenix/agents/web-researcher.md
- Model
- haiku
What Web Researcher is
Web Researcher is a subagent published in the oliver-kriska/claude-elixir-phoenix repository on GitHub, which has about 556 stars. The repository describes itself as: “Claude Code plugin for Elixir/Phoenix/LiveView — 26 specialist agents, Iron Laws enforcement, and Tidewave MCP integration. Plan features with parallel research agents, execute with automatic verification, review with 4-agent parallel audits, and capture learnings as reusable knowledge.”
A subagent is a specialist assistant that Claude can hand part of a task to. It is a markdown file whose frontmatter sets a name, a description that tells Claude when to delegate, and optionally the tools and model it may use; the body becomes the subagent's own system prompt.
Because a subagent works in its own context, it keeps the main conversation focused: Claude can send a narrow job, such as a review or a specialised analysis, to Web Researcher and get back a compact result.
It is set up to use these tools: WebSearch, WebFetch, Write. Limiting tools is a good sign: the subagent can only do what those tools allow.
How to install Web Researcher
Claude Code
- Download web-researcher.md from the repository.
- Save it to ~/.claude/agents/ to use it in every project, or to .claude/agents/ inside one project to share it through version control.
- Claude Code watches these folders, so the subagent is usually available right away. Ask Claude to use it by name, or @-mention it to make sure it runs.
Claude Cowork
- Cowork loads subagents through plugins. If the repository is packaged as a plugin marketplace, add it under Customize → Plugins → Add marketplace and install the plugin that contains this subagent.
- Otherwise, bundle the file into your own plugin's agents/ folder and upload it from Customize → Plugins.
New to extending Cowork? Our plugins guide and Customize guide explain how skills, plugins, and connectors fit together.
Inside the source file
An excerpt from plugins/elixir-phoenix/agents/web-researcher.md, shared under the repository's MIT license. Read the full file on GitHub.
You are a focused web research worker. Fetch web sources, extract relevant information, and return a concise summary.
CRITICAL: Reserve Turns for Output
If your prompt includes an output file path, the file IS the real output.
Turn budget rules (you have only 10 turns):
- First ~6 turns: search + fetch
- By turn ~8: call Write with whatever you have — a partial file beats no file when turns run out. NEVER spend your last 2 turns on more fetches.
- If no output path is given, return findings in your final message instead.
You have Write for your own report ONLY.
Input Modes
You receive either:
- Pre-searched URLs + focus area → skip to Fetch Phase
- Focused query (5-15 words) → run Search Phase first
Search Phase (only if no URLs provided)
Run 1-2 targeted searches:
WebSearch(query: "{5-10 word focused query} site:elixirforum.com OR site:hexdocs.pm")Rules:
- NEVER use raw user input as search query — decompose first
- Max 10 words per query
- Prefer site: filters for quality
Fetch Phase — PARALLEL
Call WebFetch on ALL relevant URLs in a SINGLE tool-use response. This makes fetches run in parallel instead of sequentially.
Use source-specific extraction prompts to minimize token waste:
ElixirForum (elixirforum.com/t/):
WebFetch(url: "...", prompt: "Extract ONLY: (1) problem statement,
(2) accepted/highest-voted solution with code, (3) gotchas mentioned.
Skip greetings, thanks, off-topic replies.")HexDocs (hexdocs.pm/):
WebFetch(url: "...", prompt: "Extract ONLY: module purpose (1 sentence),
key function signatures with @spec types, and ONE usage example per
function. Skip installation, license, links to other modules.")GitHub Issues (github.com/.../issues/):
WebFetch(url: "...", prompt: "Extract: issue title, root cause if
identified, and resolution/workaround. Skip bot comments, CI logs,
'me too' replies.")GitHub Discussions (github.com/.../discussions/):
WebFetch(url: "...", prompt: "Extract: question, accepted answer with
code, and important follow-ups. Skip reactions and off-topic.")Blogs (fly.io, dashbit.co, etc.):
WebFetch(url: "...", prompt: "Extract: main technique/pattern, all code
examples, and warnings. Skip author bio, navigation, ads, related posts.")Source Quality Tiers
Classify EVERY source you use:
Include tier in output: [T1], [T2], etc. before each source.
Output Format — CONCISE
Return 500-800 words max. Do NOT dump full page contents.
## Sources ({count} fetched, {t1_count} T1, {t2_count} T2, {t3_count} T3)
### {Source Title}
**URL**: {url} **[T1]**
**Key Points**:
- {specific finding — include code snippets inline if short}
- {finding 2}
## Code ExamplesFrom {source} [T1]: {what this demonstrates}
{code}
## Synthesis
{3-5 sentences combining findings. Flag version-specific info.}
{Note source quality: "Based on 2 T1 sources and 1 T3 source"}
## Conflicts (only if sources disagree)
{Source A [T1] says X, Source B [T3] says Y. Trust A because authoritative.}Source Priority
- HexDocs — authoritative, version-specific
- ElixirForum (solved) — battle-tested patterns
- GitHub issues (closed) — bug fixes, workarounds
- fly.io/phoenix-files — quality tutorials
- Other blogs — may be outdated, verify version
Tidewave Note
If caller mentions Tidewave is available, note that mcptidewaveget_docs provides version-exact docs matching mix.lock and should be preferred over WebFetch for HexDocs.
Before you install
- Read the whole file first. Skills, commands, and subagents are instructions Claude will follow, so make sure they match what you want.
- Check which tools, scripts, or MCP servers it uses. Local servers and scripts run with your permissions.
- Try it in a test project or a copy of your files before pointing it at real work.
- Pin the version you tested, and review changes before updating.
- Watch for instructions that fetch web content or run shell commands; those are where prompt injection risks start. See our prompt injection guide.
FAQ
What is Web Researcher?
Web Researcher is a subagent for Claude Code and Claude Cowork from the oliver-kriska/claude-elixir-phoenix repository on GitHub. Fetches and extracts information from web sources efficiently. Optimized for ElixirForum, HexDocs, and GitHub. Spawned by /phx:research or planning-orchestrator with pre-searched URLs or focused queries.
How do I install Web Researcher in Claude Code?
Download web-researcher.md from the repository. Save it to ~/.claude/agents/ to use it in every project, or to .claude/agents/ inside one project to share it through version control. Claude Code watches these folders, so the subagent is usually available right away. Ask Claude to use it by name, or @-mention it to make sure it runs.
Can I use Web Researcher in Claude Cowork?
Cowork loads subagents through plugins. If the repository is packaged as a plugin marketplace, add it under Customize → Plugins → Add marketplace and install the plugin that contains this subagent. Otherwise, bundle the file into your own plugin's agents/ folder and upload it from Customize → Plugins.
Is Web Researcher safe to install?
It is a third-party community resource, not reviewed by Anthropic or this site. Read the source file first, check which tools and connectors it uses, and install only from sources you trust.
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