moltline-mcp
A thin, dependency-free stdio bridge to Moltline Studio's fleet of 22 hosted MCP servers.
Most modern MCP clients can connect to the fleet directly over Streamable HTTP — no install needed (see Direct connection below). This bridge exists for clients that only speak the stdio transport: it proxies newline-delimited JSON-RPC between your client and the hosted server, verbatim, with no telemetry and no dependencies beyond the Python 3.9+ standard library.
- 160 tools across 22 servers; 110 are free.
- Free tier: no registration, no account, no credentials — connect and call tools immediately.
- Premium tools are unlocked with a Moltline license. Set
MOLTLINE_LICENSE in your MCP client's environment; the bridge sends it as the X-Moltline-License header and never writes it to argv, URLs or logs. See auth.md.
- Independently checked by MCPize on the direct endpoints (scans of 5–6 September 2026: 6 A+, 15 A, 1 B+; scores 89–98). All 22 servers score 100 on clarity, 100 on reliability and 100 on trust, 95 on protocol and 87 on safety; the one finding raised on every server is that the free tier accepts anonymous access — which is the point of it — and the spread between servers sits in MCPize's "Market" dimension (a crowded category). Each server's MCPize listing links its own public result.
Find it on: Smithery · MCPize · Glama · Clawmart · MCP Registry
The fleet
| Server | Tools | What it does |
|---|
catalog | 10 | Search 138 agent skills and personas by plain-language job; preview any product. |
codereview | 7 | Risk-scan a diff, flag AI-generated-code tells, find secrets, report complexity. |
govern | 8 | Audit an MCP config or SKILL.md for over-broad scope and prompt-injection risk. |
timeops | 5 | Business days, meeting overlap, recurrence expansion, deadline and SLA math. |
data | 7 | Paste-your-data analytics: CSV profiling, A/B tests, correlation, growth, cohorts. |
humanizer | 5 | Find AI-isms with evidence, fingerprint a writing voice, measure burstiness. |
business | 8 | 30 finance, bookkeeping, legal-ops and SMB operations persona-skill products. |
creator | 8 | 20 blogging, brand-voice, copywriting, video and social persona-skill products. |
educator | 7 | 8 curriculum, classroom, accommodations and exam-prep persona-skill products. |
outbound | 8 | 7 outreach, sequencing, deliverability, call-coaching and CRM-hygiene products. |
personal | 9 | 20 inbox, calendar, travel, meals and family-logistics persona-skill products. |
research | 8 | 7 research navigation, thesis, note-taking and citation persona-skill products. |
skillmd-lint | 6 | Lint a SKILL.md for frontmatter, structure, secrets and size. All tools free. |
merchant | 6 | Commerce arithmetic: processor fees, charge-to-net, invoice totals, proration. |
shipping | 6 | Dimensional weight, parcel fit, landed cost, freight class, rate cards. |
shopify | 6 | Check a product CSV, URL handles, variant matrices and metafield keys. |
dropship | 6 | Dropshipping unit economics: margin, lead time, SKU mapping, price ladders. |
recall | 6 | A portable knowledge-graph memory you pass in and get back. No database. |
vision | 6 | Image header probing, bbox conversion, resize plans, color and detection math. |
regclock | 9 | Incident-reporting deadlines from the legal text (EU CRA, NIS2, DORA, GDPR, UK GDPR, HIPAA, SEC 8-K), cited. |
taxlots | 8 | Crypto cost basis: parse exchange CSVs, lint, match transfers, FIFO/LIFO/HIFO lots, Form 8949 rows, 1099-DA diff. |
optimize | 11 | OR-Tools routing, 3-D packing, 1-D/2-D cutting, knapsack and shift rostering with stated limits. |
Machine-readable discovery: api-catalog · per-server card at https://mcp.moltlinestudio.com/<server>/.well-known/mcp/server-card.json · fleet health.
Direct connection (preferred)
If your MCP client supports Streamable HTTP (Claude Desktop, Claude Code, Cursor, and most current clients do), point it straight at the hosted endpoint — nothing to install:
{
"mcpServers": {
"moltline-timeops": {
"type": "http",
"url": "https://mcp.moltlinestudio.com/timeops"
}
}
}
Swap timeops for any slug in the table above.
The stdio bridge (for stdio-only clients)
Install
Run directly (recommended) — the bridge is a single stdlib-only file, so a
clone is all you need:
git clone https://github.com/GarphenGate/moltline-mcp.git
python3 moltline-mcp/moltline_mcp.py timeops
Docker — see Docker below if you prefer a container.
A PyPI package is planned; until then, use the methods above.
Client configuration
Point your MCP client at the script with an absolute path:
{
"mcpServers": {
"moltline-timeops": {
"command": "python3",
"args": ["/absolute/path/to/moltline-mcp/moltline_mcp.py", "timeops"]
}
}
}
Or run it through Docker (after docker build -t moltline-mcp .):
{
"mcpServers": {
"moltline-timeops": {
"command": "docker",
"args": ["run", "-i", "--rm", "moltline-mcp", "timeops"]
}
}
}
CLI
python3 moltline_mcp.py [server] [--timeout SECONDS] [--list] [--version]
server — one of the 22 slugs (default catalog); anything else fails fast with the valid list.--timeout — per-request timeout in seconds (default 300, or env MOLTLINE_TIMEOUT).--list — print the server slugs and exit.- Env
MOLTLINE_BASE_URL — override the fleet base URL (for testing).
- Env
MOLTLINE_LICENSE — your Moltline license, sent as the X-Moltline-License
header to unlock premium tools. Omit it and the bridge runs free-tier only.
- Env
MOLTLINE_DEBUG=1 — diagnostic logging on stderr (stdout stays protocol-clean).
The license is never logged; debug output reports only whether one is configured.
Docker
The bridge also runs containerized (stdio in, network egress to the fleet required):
docker build -t moltline-mcp .
docker run -i --rm moltline-mcp timeops
See Client configuration for the matching mcpServers entry.
How it works
One process per server connection. Each JSON-RPC message read from stdin is POSTed to https://mcp.moltlinestudio.com/<server>; JSON and SSE-framed responses are relayed back to stdout as newline-delimited JSON. The bridge tracks the server-assigned Mcp-Session-Id and echoes the negotiated MCP-Protocol-Version, per the Streamable HTTP transport spec. It never inspects, stores, or reports your traffic.
Tests
The bridge ships with an offline test suite - no network, no dependencies:
Twenty-two tests cover the parts that actually break in a transport bridge:
newline-delimited framing, SSE event splitting (multiple events, multi-line
data: payloads, a trailing event with no blank line, comments and named
events), session-id capture and reuse, protocol-version negotiation on
initialize only, and error relay - a JSON-RPC error document is passed
through verbatim, anything else becomes a well-formed -32603. CI runs them
on Python 3.9, 3.12 and 3.13, plus a Docker build and container smoke test.
Access and licensing
- Free tier — anonymous. No registration or credentials; all free tools work immediately.
- Premium — unlocked with a Moltline license purchased (human-in-the-loop) at moltlinestudio.com. Set
MOLTLINE_LICENSE in the environment and the bridge forwards it as the X-Moltline-License request header. It is deliberately not a command-line flag: argv is world-readable through ps. It is never placed in a URL and never logged. Details: auth.md.
Links
License
MIT © 2026 Moltline Studio