Agent Web Search gives an agent two ways to reach the same provider-neutral search core: a native MCP tool, or a CLI taught through a standard Agent Skill. Both dispatch enabled providers concurrently, normalize them into one schema, and isolate provider failures.

Agent ──┬── MCP client ────── web_search ──┐
        │                                  │
        └── Shell + Skill ── CLI command ──┤
                                           ▼
                                      SearchEngine
                                           │
                     DDGS · Exa · Parallel · ARK · Brave
                     Gemini · Grok · Perplexity · Tavily · You.com

Why Agent Web Search

• Concurrent, independent providers. All selected providers run at the same time, and one provider's failure never discards another provider's results.
• Zero-key start. The default providers — DDGS, Exa, and Parallel — work without any API key.
• Two clean agent integrations. Use MCP for a protocol-native tool, or pair the CLI with the included Skill for agents that already have shell access.
• Focused responses. Every provider response contains only a generated answer when available and normalized results.
• No telemetry, no shared secrets. Provider keys stay in runtime environment variables; there is no shared API-key service.

Providers

Free, keyless defaults: DDGS, Exa, and Parallel all work without an API key. Exa and Parallel automatically use their free MCP transports until a paid API key is provided.

The provider architecture is intentionally open: another search-capable backend can be added without changing the MCP, Hermes, CLI, or Python-facing interfaces.

Use with an agent

Requirements: Python 3.10+. The default providers — DDGS, Exa, and Parallel — need no API key. Choose one integration shape for your agent; both use the same package and search engine. The PyPI package installs both agent-web-search-mcp and agent-web-search commands.

Option 1: MCP

Choose MCP when the agent supports tool servers and you want typed discovery, protocol-level errors, or remote access. The same agent-web-search-mcp command supports local stdio and stateless Streamable HTTP.

Local stdio MCP

Install the package once:

# Recommended isolated installation
pipx install agent-web-search-mcp

# Or install into the active Python environment
python -m pip install agent-web-search-mcp

Then configure the MCP client to launch agent-web-search-mcp:

{
  "mcpServers": {
    "agent-web-search": {
      "command": "agent-web-search-mcp",
      "args": []
    }
  }
}

If uvx is already available, a client can run the package without a persistent install by using command uvx with args ["agent-web-search-mcp"].

# Codex CLI
codex mcp add agent-web-search -- agent-web-search-mcp

# Claude Code
claude mcp add agent-web-search -- agent-web-search-mcp

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "agent-web-search": {
      "type": "local",
      "command": ["agent-web-search-mcp"],
      "enabled": true
    }
  }
}

Remote MCP over HTTPS

Use one of the deployment buttons at the top of this README, or run the same server yourself:

python -c "import secrets; print(secrets.token_urlsafe(32))"
export AGENT_WEB_SEARCH_AUTH_TOKEN="replace-with-the-generated-token"
agent-web-search-mcp --transport http

The server exposes authenticated POST /mcp and public GET /healthz. A remote MCP client connects like this:

{
  "mcpServers": {
    "agent-web-search": {
      "url": "https://your-deployment.example/mcp",
      "headers": {
        "Authorization": "Bearer your-deployment-token"
      }
    }
  }
}

Every public deployment must set AGENT_WEB_SEARCH_AUTH_TOKEN to at least 32 characters. The server is stateless and does not create MCP-Session-Id values.

Option 2: CLI + Skill

Choose this shape when the agent already has shell access and supports Agent Skills. The Skill teaches the agent how to invoke the CLI, select controls, interpret results, and handle structured failures; no MCP configuration is needed.

1. Install the CLI:

   pipx install agent-web-search-mcp
   # Or: python -m pip install agent-web-search-mcp
   

2. Install the included agent-web-search Skill:

   npx skills add JerryLiu369/agent-web-search --skill agent-web-search
   

   If the agent does not use the skills installer, copy skills/agent-web-search into that client's Skills directory.

3. Verify the CLI, then let the agent search:

   agent-web-search --version
   agent-web-search "What changed in the latest OpenAI Codex CLI?"
   

The CLI writes one JSON document to stdout on success. If every provider fails, it writes the shared all_providers_failed JSON to stderr and exits with status 1, so shell-capable agents can distinguish a real failure from empty results.

pipx install 'git+https://github.com/JerryLiu369/agent-web-search.git'

[!IMPORTANT] Do not place API keys in shell history, source code, Git commits, screenshots, or checked-in MCP configuration. Supply them through server-side or local environment variables.

Shared request and response

MCP exposes one tool named web_search; the CLI maps to the same inputs.

Example call:

{
  "query": "GPU kernel generation papers from the past month",
  "max_results": 5,
  "time_range": "m",
  "providers": ["ddgs", "exa"]
}

Provider selection has two levels:

1. AGENT_WEB_SEARCH_PROVIDERS defines the provider set when the process starts.
2. The request-level providers argument may narrow that set, but cannot enable a provider that was disabled at startup.

Response format

Each selected provider that succeeds appears under providers; failed providers are omitted:

{
  "query": "GPU kernel generation papers from the past month",
  "providers": {
    "ddgs": {
      "results": [
        {
          "title": "Example result",
          "url": "https://example.com/paper",
          "description": "Excerpt of the matching page",
          "published_at": "2026-08-02"
        }
      ]
    }
  }
}

If every selected provider fails, MCP returns a tool error. The CLI writes the same payload to stderr and exits with status 1. Both use the stable code all_providers_failed and include per-provider diagnostics:

{
  "error": {
    "code": "all_providers_failed",
    "message": "All enabled search providers failed. Check provider configuration, credentials, quotas, and network access.",
    "provider_errors": {
      "ddgs": "RuntimeError: rate limited"
    }
  },
  "query": "GPU kernel generation papers from the past month"
}

Python API

The CLI, MCP servers, and Hermes plugin are thin wrappers around agent_web_search.SearchEngine, which is the public Python API. SearchRequest accepts the same fields as the MCP tool arguments:

from agent_web_search import SearchEngine, SearchRequest

engine = SearchEngine()  # reads AGENT_WEB_SEARCH_* variables at construction

response = engine.search(
    SearchRequest(query="latest MCP spec changes", max_results=5, time_range="m")
)

for name, provider in response.providers.items():
    print(f"{name}: searched={provider.searched}, results={len(provider.results)}")

if response.all_providers_failed:
    print(response.failed_provider_errors)

Configuration

Configuration is read from environment variables when the CLI, MCP server, or Hermes plugin starts. Restart the process after changing provider settings. See .env.example for a commented template of every variable.

General settings

Example:

export AGENT_WEB_SEARCH_PROVIDERS="ddgs,exa,brave"
export AGENT_WEB_SEARCH_TIMEOUT="30"

$env:AGENT_WEB_SEARCH_PROVIDERS = "ddgs,exa,brave"
$env:AGENT_WEB_SEARCH_TIMEOUT = "30"

HTTP transport settings

HTTP settings remain environment-only; the deployment files do not introduce a second application configuration format.

Provider settings

Default providers are listed first; optional providers then follow alphabetical order.

1. DDGS

DDGS uses DuckDuckGo and requires no API key or provider-specific environment variables. The ddgs Python dependency is installed with the package.

2. Exa

Exa supports both paid and keyless modes.

Without EXA_API_KEY, Exa falls back to its free MCP endpoint on a best-effort basis. The paid API generally provides higher quota and reliability.

3. Parallel

Parallel returns information-dense excerpts ranked for LLM context. One parallel provider automatically selects its transport:

• Without a key, it uses Parallel's free Search MCP.
• With PARALLEL_API_KEY, it uses the paid Search REST API.

Both transports map excerpts into the common result description, so the calling agent does not need to distinguish parallel-free from parallel.

Parallel is enabled by default and its key is optional.

4. ARK (Recommended)

Volcengine ARK uses model-backed search grounding through the Responses API. Add ark to AGENT_WEB_SEARCH_PROVIDERS after providing the key.

One model stays fixed; multiple models are selected round-robin for successive requests. When multiple ARK keys are configured, a key is selected per request.

5. Brave

Add brave to AGENT_WEB_SEARCH_PROVIDERS after providing the key.

6. Gemini

Gemini maps common result and time controls into best-effort prompt constraints. One configured model stays fixed; multiple models are selected round-robin for successive requests.

7. Grok

One configured model stays fixed; multiple models are selected round-robin for successive requests.

When Grok is enabled, the public tool schema adds grok_search_mode:

• web_search searches the web.
• x_search searches X with native date filters when available.
• both exposes both server-side tools in one request and lets Grok choose; it does not issue two independent model requests.

8. Perplexity

This provider uses Perplexity's native structured Search API. It returns result rows rather than a Sonar-generated prose answer; OpenRouter compatibility is intentionally outside this provider's scope.

Add perplexity to AGENT_WEB_SEARCH_PROVIDERS after providing the key.

9. Tavily

Add tavily to AGENT_WEB_SEARCH_PROVIDERS after providing the key.

10. You.com

You.com returns unified web and news sections. Agent Web Search merges both, deduplicates URLs, and applies max_results to the combined result list.

Add you to AGENT_WEB_SEARCH_PROVIDERS after providing the key.

Common search controls

Each provider maps the shared controls to its native API when possible and ignores unsupported controls.

Prompt-based controls are best-effort and are not strict guarantees.

Other interfaces

Native Hermes plugin

Install the native plugin directly from GitHub:

pip install 'ddgs>=9.0'
hermes plugins install JerryLiu369/agent-web-search --no-enable
hermes plugins enable agent-web-search --allow-tool-override

The plugin intentionally replaces Hermes' built-in web_search tool, so the explicit --allow-tool-override grant is required. Start a new Hermes session after enabling it; restart the gateway when using a messaging channel.

Hermes can also connect through its generic MCP integration instead of the native plugin.

Troubleshooting

• all_providers_failed — every selected provider errored. MCP marks the call as an error; the CLI writes diagnostics to stderr and exits 1. Check keys, quotas, and network access. A single retry may help a transient limit.
• agent-web-search is not found — install the PyPI package with pipx or pip, then start a new shell so its scripts directory is on PATH.
• HTTP 401 invalid_token — the Authorization: Bearer … header must match AGENT_WEB_SEARCH_AUTH_TOKEN, which must be at least 32 characters.
• A provider is missing from a response — failed providers are omitted from successful responses. The Python API exposes the reasons in response.failed_provider_errors.
• Provider changes have no effect — provider settings are read once at startup; restart the CLI, MCP server, or Hermes plugin after changing them.
• MCP client times out before the tool returns — AGENT_WEB_SEARCH_TIMEOUT bounds a single upstream HTTP call, not the whole search. Keyless Parallel issues up to 3 calls and ARK may append a continuation request, so the worst case is 3 × AGENT_WEB_SEARCH_TIMEOUT; configure your MCP client's tool timeout accordingly.

Development

Using uv keeps the development environment isolated and reproducible:

git clone https://github.com/JerryLiu369/agent-web-search.git
cd agent-web-search
uv venv
uv pip install -e '.[dev]'
uv run pytest -q
uv run ruff check .

python -m venv .venv
# Linux/macOS: source .venv/bin/activate
# Windows PowerShell: .venv\Scripts\Activate.ps1
python -m pip install -e '.[dev]'
pytest -q
ruff check .

ARCHITECTURE.md is the design source of truth, and AGENTS.md lists the non-negotiable invariants. Read both before changing transports, configuration, authentication, deployment, providers, or tool schemas, keep stdio and HTTP behavior identical, and keep pytest and ruff green in the same change.

License

MIT