Frugal

Your agent doesn't shop around. Frugal does.

The same web search costs $0 on Wikipedia, Marginalia, or SearXNG, $0.001 on Serper, $0.005 on You.com — and agents pick providers by what's wired in, not by price. For search-heavy agents that's most of the bill: in one Deep Research teardown, search alone was 54% of task cost.

Frugal is an MCP server that routes every search / extract / browse call down the price ladder: free and local first, cheap paid next, premium only when nothing cheaper returns a result. Every response carries provider_used and cost_usd, so the routing decision is auditable right in the agent's trace.

Works with any model. One Go binary. Your keys. No account. Source-available (BUSL 1.1 → Apache 2.0).

frugal.sh

Install

curl -fsSL https://frugal.sh/install | bash
frugal mcp install

The first command drops the binary in your $PATH. The second auto-detects Claude Desktop, Cursor, and Claude Code and merges frugal into each configured MCP server list.

Try it now (no keys)

Search and extract work out of the box: Marginalia (free index of the indie / non-commercial web), Wikipedia (free Wikimedia REST search), and go-readability (free, pure-Go local extractor) ship enabled with zero configuration. When a provider comes up empty, the chain falls through to the next one. Captured from a live zero-key run:

frugal__search {"query": "AI agent framework comparison", "max_results": 3}

  stderr › search zero hits; falling back  provider=marginalia latency_ms=529
  result › {
    "provider_used": "wikipedia",
    "cost_usd": 0,
    "latency_ms": 954,
    "results": [
      {"title": "Gemini Enterprise Agent Platform", "url": "https://en.wikipedia.org/wiki/Gemini_Enterprise_Agent_Platform", ...},
      {"title": "Perplexity AI", "url": "https://en.wikipedia.org/wiki/Perplexity_AI", ...},
      {"title": "Agentic commerce", "url": "https://en.wikipedia.org/wiki/Agentic_commerce", ...}
    ]
  }

Honest limits: Marginalia is genuinely good for essays, docs, blogs, and niche technical writing, and weak on mainstream news and product pages; Wikipedia covers entities and reference topics. Zero-key mode is a real workflow for research and local extraction — it is not a Google-grade SERP. One env var changes that: SEARXNG_URL (free, self-hosted) or SERPER_API_KEY ($0.001/call) gives the chain a stronger rung to fall to.

See what you kept

Every call lands in a local ledger (~/.frugal/usage, JSONL, never leaves your machine; FRUGAL_STATS=off disables it). frugal stats prints the month's receipt:

frugal receipt · July 2026 (UTC)
────────────────────────────────────────────────
tool      provider            calls         paid
search    marginalia              1      $0.0000
search    wikipedia               1      $0.0000
extract   goreadability           1      $0.0000
────────────────────────────────────────────────
total                             3      $0.0000

same calls at premium rack rate*         $0.0060
you paid                                 $0.0000
────────────────────────────────────────────────
you saved                      $0.0060   (100%)
────────────────────────────────────────────────
* rack rate = list price of each capability's premium
  provider, snapshotted at call time. failed calls excluded.

Only the call that actually produced your result earns rack credit — fallback attempts and zero-hit whiffs don't inflate the number.

Set your keys (optional)

Add keys to unlock stronger paid providers. Frugal reads them from your environment and only registers tools whose providers are configured:

# Search — frugal__search
export SEARXNG_URL=...           # free, self-hosted (Marginalia + Wikipedia need no key)
export SERPER_API_KEY=...        # cheap paid
export YDC_API_KEY=...           # premium paid (You.com)

# Extract — frugal__extract (goreadability is free, no key)
export FIRECRAWL_API_KEY=...     # premium paid (JS-rendered pages)

# Browse — frugal__browse
export BROWSERLESS_TOKEN=...     # headless render

That's it. Restart your agent. frugal__search, frugal__extract, and frugal__browse show up in the tool picker (only the tools whose providers are configured get registered).

The rack-rate gap

Tool prices haven't fallen the way model prices have. You.com at $0.005/call is 5× Serper at $0.001/call. SearXNG, running on your own machine, is free.

Frugal walks the columns left to right. Each tool call goes to the leftmost configured provider that returns a result; you keep the gap.

What ships today

One MCP server, three tools, eight providers:

• frugal__search — shipping. Routed across SearXNG (free, self-hosted), Marginalia (free, public), Wikipedia (free, public), Serper ($0.001/call), and You.com ($0.005/call). When a free provider returns zero hits the chain falls through to the next rung; a paid provider returning zero hits ends the chain (the query has no hits — no point paying a pricier provider to confirm).
• frugal__extract — shipping. Routed across go-readability (free, pure-Go local Readability) and Firecrawl (~$0.001/page, JS-rendered).
• frugal__browse — partial. Browserless (~$0.002/render, headless Chrome) shipping; local Playwright deferred.
• frugal stats — the local savings receipt (see above).
• Stdio + Streamable HTTP transports.
• HTTP transport supports bearer-token auth (FRUGAL_AUTH_TOKEN), per-IP rate limiting, and a /metrics endpoint (Prometheus text: frugal_calls_total{tool=,provider=} etc.).
• frugal mcp install writes the right config into Claude Desktop, Cursor, and Claude Code.

What's coming

• Phase 3 — embeddings, transcription, code execution, local chat models, semantic cache.
• Phase 4 — Frugal Cloud: hosted MCP endpoint for users who don't want to operate the local stack themselves.

From source

git clone https://github.com/brainsparker/frugal.git && cd frugal && make build

License

BUSL 1.1 — self-hosting and internal commercial use are permitted. Each release converts to Apache 2.0 four years after publication. Plain-English summary in LICENSE-BUSL-FAQ.md.

Security

Private vulnerability reports via GitHub Security Advisories. Full policy in SECURITY.md.