Lantern Works GPU prices — MCP server (v0.3.45, read-only, stdio)

mcp-name: io.github.connormatthewdouglas/lantern-works-deals

Free, read-only, no API key. GPU price comparison for agents, checked daily: compare_gpu_prices returns hourly rental prices for H100, A100, RTX 4090 and more across tracked providers, cheapest first, each with the vendor's source page and check date; include_history=true adds daily price history (since 2026-10-27) and recent changes. Also prices the cheapest stack for your monthly usage (optimize_stack) and, last, searches and compares AI-infra deals and free tiers, ranked by customer value (never by affiliate status). Some result links are referral links.

Quick start

uvx lantern-works-deals-mcp

Claude Code:

claude mcp add lantern-works-deals -- uvx lantern-works-deals-mcp

Cursor (.cursor/mcp.json), Cline (cline_mcp_settings.json) and Claude Desktop (claude_desktop_config.json):

{
  "mcpServers": {
    "lantern-works-deals": {
      "command": "uvx",
      "args": ["lantern-works-deals-mcp"]
    }
  }
}

Without uv: pip install lantern-works-deals-mcp, then use "command": "lantern-works-deals-mcp". Docker (from the repo root; installs the pinned PyPI release): docker build -t lantern-works-deals-mcp . && docker run -i --rm lantern-works-deals-mcp. More clients: https://thelanternworks.com/install/

Hosted endpoint (no install)

Streamable HTTP, same read-only tools: https://lantern-works-mcp.lantern-works.workers.dev/mcp?ref=pypi-readme (claude mcp add --transport http lantern-works-deals https://lantern-works-mcp.lantern-works.workers.dev/mcp?ref=pypi-readme). Free Cloudflare Worker; it stores only anonymous call counts per tool per day (no IPs, user agents or arguments), public at https://lantern-works-mcp.lantern-works.workers.dev/stats. ?ref= only tags which link was used.

Tools

compare_gpu_prices uses exactly the data published at https://thelanternworks.com/api/v1/gpu-prices.json (history: https://thelanternworks.com/api/v1/gpu-prices/history.json). Prices are re-read daily from each vendor's own page or API and change only where a price was parsed; a rate not re-verified for 7 days is held out of rankings. Model matching is by whole tokens (H100 matches H100 SXM; L40 does not match L40S). "Cheapest" means cheapest among tracked providers, not the whole market.

Errors: {"error": {"code": "invalid_argument|invalid_cursor|not_found|feed_unavailable|feed_invalid", "message": ...}}.

Hours cap

optimize_stack/optimize_agent_stack gpu_hours, estimate_job_cost job_hours (given or computed) and the browser calculator all accept at most 20,000 hours, not GPU-hours (wall-clock duration per GPU). 2,501 h on 8 GPUs is valid; the GPU count has its own limit. Larger values return invalid_argument.

Errors and isError

stdio and hosted use one rule (core/contract.is_error): isError is true exactly when the result is the error envelope {"ok": false, "error": {"code", "message"}}. Invalid input (invalid_argument), an unknown or unsupported GPU, vendor or workload (not_found) and upstream failures (feed_unavailable, upstream_unavailable, ...) are errors. A valid query that matches nothing is not an error: ok: true, count: 0, an empty list, isError: false. structuredContent is the same object in both cases. Arguments are checked the same way in both before the tool runs: a missing required argument, a wrong JSON type or an unknown extra argument (schemas set additionalProperties: false) returns invalid_argument. Unknown tool name is a protocol error, not a tool result: hosted answers JSON-RPC error -32602, stdio returns the MCP SDK's isError text "Unknown tool".

Retrieval status (cached data)

Every successful tool result carries retrieval: {"status": "ok"|"degraded", "feeds": [...]}. Each feed entry has last_successful_retrieval_at, last_refresh_attempt_at, last_refresh_outcome (ok, failed: <error>, invalid: <error>), stale_cache and cache_age_s. When a refresh fails (outage) or returns an unusable feed (partial refresh), the last good copy is served and marked degraded. Policy: cached data answers current-price questions for at most 60 minutes after the last successful retrieval; after that the tool returns feed_unavailable. Price history and change logs stay readable from cache. A successful refresh clears the degraded state. Price verification times (checked_at, verified_at) are separate and unchanged.

Data and privacy

Deals: https://thelanternworks.com/api/v1/deals.json; stack pricing: https://thelanternworks.com/api/v1/stack-pricing.json; GPU prices: https://thelanternworks.com/api/v1/gpu-prices.json. Each is cached 5 min (a stale copy is served if a refetch fails). Requests send only User-Agent: lantern-works-deals-mcp/<version> (no user, host or install identifiers). Overrides: LANTERN_DEALS_FILE / LANTERN_DEALS_URL, LANTERN_GPU_PRICES_FILE / LANTERN_GPU_PRICES_URL, LANTERN_STACK_PRICING_FILE / LANTERN_STACK_PRICING_URL. Only an allow-list of public fields is returned.

Telemetry: off by default. Opt in with LANTERN_TELEMETRY=1 to send an anonymous daily count of tool calls. Each count is only the tool name, package version, UTC day and number of calls. No arguments, IDs or IPs are sent or stored. It is batched to at most one request per day and never blocks or breaks a tool call. Details: PRIVACY.md.

From git (fallback)

git clone https://github.com/connormatthewdouglas/agent-work-stack-deals.git
cd agent-work-stack-deals
python3 -m venv .venv && .venv/bin/pip install -r mcp_server/requirements.txt
.venv/bin/python mcp_server/server.py

Test

.venv/bin/pip install pytest && .venv/bin/python -m pytest -q tests
python3 scripts/test_pypi_install.py --uvx   # clean venv + uvx install from PyPI, calls every tool over stdio

Package

pyproject.toml at the repo root builds lantern-works-deals-mcp (MIT) with a lantern-works-deals-mcp console command. Published on PyPI and in the MCP Registry as io.github.connormatthewdouglas/lantern-works-deals.

License

The package code is MIT. The price and deal data it reads (the Lantern Works feeds) is CC BY 4.0: credit "Lantern Works" and link to https://thelanternworks.com. See https://thelanternworks.com/methodology/#license.