System · Harbor
Pricing
Why MCP is open source — COGS research and cost-plus decision.
Pricing — why the MCP is open source
Cost research (Aug 2026). Decision: open source every design-contract MCP.
Charging for compute we do not run fails the “~50% markup on real cost” bar.
What customers actually run
| Piece | Where it runs | Cost to the publisher |
|---|---|---|
MCP server (packages/contract-mcp) | Customer machine via stdio (Cursor / Claude Desktop spawns it) | $0 — stdio has no hosting cost |
Contract JSON /r/{id}.contract.json | Static file on the catalog site (CDN) | Negligible bandwidth on existing site hosting |
Machine docs (design.md, agents.md, …) | Same site / negotiated routes | Negligible |
validate_ui / recipes | Local CPU in the MCP process | $0 to the publisher |
For the default install path, per-contract MCP marginal cost ≈ $0/month.
If we hosted remote MCP (optional later)
Only needed for cloud agents that cannot spawn stdio. Ballpark infra (shared across all contracts, not per system):
| Option | Typical monthly floor | Notes |
|---|---|---|
| Cloudflare Workers Free | $0 | 100k requests/day, 10ms CPU/invocation |
| Workers Paid | $5 | 10M requests + 30M CPU-ms included |
| Small VPS / Railway-class | ~$5–10 | Long-lived Streamable HTTP (hosting survey) |
| Site itself (Vercel Hobby → Pro) | $0 → $20/seat | Already needed for the catalog; not MCP-specific (Vercel pricing) |
Even at $5–20/mo total remote infra for the whole platform, a 50% markup is ~$7.50–30/mo for the entire product, not $9 per contract per seat. Spreading that across users makes per-seat MCP fees pennies — not a credible paid SKU.
Decision
| Model | Verdict |
|---|---|
| $9/mo per MCP | Rejected — markup on ~$0 (stdio) or shared ~$5 infra is not honest |
| Open source MCP + contracts | Ship this — cost is negligible; distribution is the product |
| Paid later (optional) | Hosted remote MCP with auth, team analytics, or support retainers — only if real COGS appear |
Platform constant: MCP_PRICE_USD = 0 · pricingModel: "open-source" in lib/platform/skeleton.ts.