ChemCP vs Marrow

A side-by-side look at the ChemCP and Marrow MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.

ChemCP logoChemCPBiology & Bioinformatics · Local subprocess (stdio)MCP App that renders 2D molecular structures from SMILES using RDKit.js40FairAuth: not declaredMarrow logoMarrowBiology & Bioinformatics · Local subprocess (stdio)Read-only MCP access to your own Apple Health data, mirrored from the Marrow iOS app.55GoodAuth: api key required

Verdict: choose ChemCP for biology & bioinformatics work as a local process; choose Marrow for biology & bioinformatics as a local process. You can also run both side by side in one mcpServers block.

Which MCP server should you choose?

ChemCP logoChoose ChemCP when

  • You need dedicated capabilities in the Biology & Bioinformatics domain.
  • You prefer a local stdio subprocess transport.
Explore ChemCP

Marrow logoChoose Marrow when

  • You need dedicated capabilities in the Biology & Bioinformatics domain.
  • You prefer a local stdio subprocess transport.
  • Its auth model fits you: API key required.
  • You want tools like health_summary, list_metrics, metric_daily.
Explore Marrow

Feature & specification comparison

Rows where the two servers differ are marked.

SpecChemCP logoChemCPMarrow logoMarrow
CategoryBiology & BioinformaticsBiology & Bioinformatics
Quality signal40/100 · Fair55/100 · Good
Install commandConfirmedConfirmed
TransportLocal subprocess (stdio)Local subprocess (stdio)
AuthNot declaredAPI key required
PricingNot declaredFree
Required env varsNone listedNone listed
Verified ownerCommunity listingCommunity listing
GitHub stars23
Directory activity 1 views 0 installs 0 upvotes 3 views 0 installs 0 upvotes
ToolsNot listed9

Tools & capabilities

ChemCP tools

No tool names declared yet. Check the project README from the listing page.

Marrow tools 9

  • health_summaryRecent days across activity, heart, sleep and nutrition
  • list_metricsEvery metric in the mirror, with units and coverage
  • metric_dailyDaily values for any metric, up to 400 days
  • metric_samplesRaw records with timestamps and source devices
  • workoutsWorkouts from every source: activity, start, end, duration and source
  • nutrition_logThe meal diary: every logged food with full nutrient detail, by day
  • strength_logEvery lifting set with its set type and estimated 1RM, per-exercise progression, and volume per muscle group (warm-ups left out)
  • sleep_logOne night per wake day: bedtime, wake time, hours asleep, minutes per stage
  • symptoms_and_moodSymptoms with their severity, and State of Mind entries with valence, feelings and what they were about

Ready-to-paste client configs

Paste either block (or both) into your client config, e.g. claude_desktop_config.json or ~/.cursor/mcp.json. We only show a config when the install command is confirmed.

ChemCP

mcpServers (Claude Desktop / Cursor)
{
  "mcpServers": {
    "chemcp": {
      "command": "npx",
      "args": [
        "-y",
        "cloudflared"
      ]
    }
  }
}

Marrow

mcpServers (Claude Desktop / Cursor)
{
  "mcpServers": {
    "marrow-4": {
      "command": "uvx",
      "args": [
        "--from",
        "marrow-mcp",
        "marrow-server"
      ]
    }
  }
}

Frequently asked questions

ChemCP is categorized under Biology & Bioinformatics and uses a local stdio subprocess. Marrow belongs to Biology & Bioinformatics and uses a local stdio subprocess. Pick ChemCP for biology & bioinformatics work and Marrow for biology & bioinformatics.

Copy the mcpServers block from the config section on this page into your client's config (for example claude_desktop_config.json or ~/.cursor/mcp.json), then fully restart the client.

ChemCP has no declared pricing — check the project's own site. Marrow is listed as free. Auth: api key required. If a server needs environment variables such as API keys, define them under the env key in your client's MCP config.

Yes. MCP clients support multiple servers: add chemcp and marrow-4 as separate keys in the same mcpServers object, and your assistant will call tools from either one.

On AllMCPs, ChemCP has a quality signal of 40/100 (Fair) with 1 views, 0 installs and 2 GitHub stars. Marrow has 55/100 (Good) with 3 views, 0 installs and 3 GitHub stars.