SIN-Code MCP Server Builder Skill
A meta-skill MCP server that scaffolds, manages, validates, and publishes MCP servers within the OpenSIN-Code ecosystem. It provides 8 tools:
Scaffold a new MCP server (
mcp_scaffold): Generate a fully structured server from a spec using templates likepython-fastmcp,node-mcp, orgo-mcp.List available templates (
mcp_template_list): View all supported templates with details like language, framework, and entry point.Add a tool to an existing server (
mcp_tool_add): Inject a new tool into an existingmcp_server.pyfile while preserving CoDocs compliance.Generate pytest tests for a tool (
mcp_tool_test): Automatically produce pytest test stubs for a specified tool.Register a server (
mcp_register): Add a server configuration (command, env vars, enabled state) toopencode.json.Validate a server (
mcp_validate): Run static checks on type hints, docstrings, CoDocs compliance, and tool structure.Publish to PyPI or npm (
mcp_publish): Deploy a server package with support for dry-run and TestPyPI modes.Run a quality audit (
mcp_audit): Execute a 47-gateceo-auditwith a configurable profile (QUICKorFULL) and minimum grade threshold.
Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type
@followed by the MCP server name and your instructions, e.g., "@SIN-Code MCP Server Builder Skill scaffold a new python mcp server called my-tool"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
Archived on July 28, 2026. This standalone repository is read-only because its functionality moved to OpenSIN-Code/SIN-Code in PR #513.
Use the canonical surface sin mcp-server. The former builder CLI shims and Python namespace sin_mcp_server_builder remain available for compatibility.
⚠️ DEPRECATED — This skill has been merged into sin-code-bundle
As of v0.9.3 (2026-06-06), this standalone skill is now a subcommand of the
sin-code-bundleCLI:
Old
New
standalone skill
sin mcp-serverMigrate now:
pip install --upgrade sin-code-bundleThis repo is archived; no further updates will be made. See issue #29 for the consolidation rationale.
SIN-Code-MCP-Server-Builder-Skill
Meta-skill that scaffolds new MCP servers for the OpenSIN-Code ecosystem. Supports
python-fastmcp,node-mcp, andgo-mcptemplates — 8 FastMCP tools, 113 tests, 100% CoDocs.
Related MCP server: mcp-starter-kit
What it does
The OpenSIN-Code ecosystem runs 30+ MCP servers (sin-websearch, sin-scheduler, sin-marketplace, sin-slash, sin-goal-mode, sin-infisical, …). Every one of them followed the same canonical pattern: pyproject.toml + src/<pkg>/mcp_server.py + tests/ + *.doc.md + ceo-audit.yml. This meta-skill codifies that pattern — give it a name + a list of tools and you get a fully scaffolded, CoDocs-compliant, ceo-audit-ready MCP server in one tool call.
Features
3 templates —
python-fastmcp(FastMCP),node-mcp(official SDK),go-mcp(go-sdk)8 FastMCP tools — scaffold, template_list, add_tool, test, register, validate, publish, audit
113 tests covering scaffolding, template rendering, tool addition, test generation, registration, validation, MCP server
100% CoDocs — every
.pyhas a sibling.doc.md6 bash scripts —
mcp-scaffold.sh,mcp-add-tool.sh,mcp-test.sh,mcp-register.sh,mcp-validate.sh,mcp-publish.shceo-audit workflow with grade gate B
Quick Start
git clone https://github.com/OpenSIN-Code/SIN-Code-MCP-Server-Builder-Skill.git
cd SIN-Code-MCP-Server-Builder-Skill
pip install -e ".[dev]"Run the MCP server
sin-mcp-server-builder-mcp
# or
python -m sin_mcp_server_builder.mcp_serverScaffold a new MCP server
./scripts/mcp-scaffold.sh -n "My Tool" -d "Does cool things" -T python-fastmcp -o "do_x,do_y"Validate a freshly scaffolded server
./scripts/mcp-validate.sh ./my-new-toolMCP Tools
Tool | Purpose |
| Scaffold a new MCP server from a spec |
| List available templates |
| Add a new tool to an existing MCP server (preserves CoDocs) |
| Generate pytest tests for a tool |
| Register the server in |
| Validate tools (type hints, docstrings, CoDocs) |
| Publish to PyPI / npm |
| Run ceo-audit (47 quality gates) |
Architecture
MCP Client (OpenCode, Claude, …)
↓ FastMCP (stdio)
mcp_server.py
↓
┌──────────────────────────────────────────────┐
│ Scaffolder │ ToolAdder │ TestGenerator │
│ Templates │ Registrar │ Validator │
│ Publisher │ Auditor │
└──────────────────────────────────────────────┘
↓
┌──────────────────────────────────────────────┐
│ python-fastmcp / node-mcp / go-mcp templates │
│ (CoDocs + ceo-audit.yml + tests + scripts) │
└──────────────────────────────────────────────┘Project Structure
SIN-Code-MCP-Server-Builder-Skill/
├── src/sin_mcp_server_builder/
│ ├── __init__.py — Package entry, public API
│ ├── mcp_server.py — FastMCP server (8 tools)
│ ├── scaffolder.py — Scaffold new servers from a spec
│ ├── templates.py — Jinja2 engine + template registry
│ ├── tool_adder.py — Add tools to existing servers
│ ├── test_gen.py — Generate pytest tests
│ ├── registrar.py — Update opencode.json
│ ├── validator.py — Static validator (47 gates subset)
│ ├── publisher.py — PyPI / npm publish
│ └── auditor.py — ceo-audit runner
├── templates/
│ ├── python-fastmcp/ — Python + FastMCP
│ ├── node-mcp/ — Node.js + @modelcontextprotocol/sdk
│ └── go-mcp/ — Go + go-sdk
├── scripts/ — Bash CLI wrappers
├── tests/ — 113 tests
├── .github/workflows/ceo-audit.yml
├── pyproject.toml
├── README.md
├── SKILL.md
└── AGENTS.mdTesting
pytest -q
pytest --cov=src/sin_mcp_server_builder --cov-report=term-missingCoDocs
Every .py file has a sibling .doc.md companion. Run sin codocs check to verify.
CI
The ceo-audit.yml workflow runs on every push to main and:
Installs the package + dev deps
Runs
pytest -qLints with
black+ruffType-checks with
mypyRuns
sin ceo-audit run . --profile=QUICK --grade=B
License
MIT — OpenSIN-Code
Available Tools
8 toolsmcp_auditC
Run a ceo-audit (47 quality gates) on a new MCP server.
Inputs: project_dir (required), grade, profile. Returns: result
mcp_publishB
Publish an MCP server to PyPI (Python) or npm (Node).
Inputs: project_dir (required), test, dry_run, registry, +1 more. Returns: result
mcp_registerB
Register a new MCP server in opencode.json.
Inputs: name (required), command (required), env, enabled, +1 more. Returns: result
mcp_scaffoldB
Scaffold a new MCP server from a spec.
Inputs: name (required), description (required), tools, target, +1 more. Returns: result
mcp_template_listA
List available MCP server templates.
Returns:
JSON array of {name, language, framework, entry_point, ...}.
Inputs: no named parameters. Returns: result
mcp_tool_addB
Add a new tool to an existing MCP server.
Inputs: tool_name (required), description (required), server_path (required), body, +1 more. Returns: result
mcp_tool_testB
Generate pytest tests for an MCP tool.
Inputs: tool_name (required), server_path (required), output_path. Returns: result
mcp_validateB
Validate an MCP server (tools, type hints, docstrings, CoDocs).
Inputs: project_dir (required). Returns: result
Tool Schema Changelog
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
Loading tool schema changelog…
TDQS
Scored across 8 tools
Each tool targets a distinct action in the MCP server lifecycle: scaffolding, tool addition, validation, audit, testing, publishing, registration, and template listing. No two tools have overlapping purposes.
All tool names follow a consistent 'mcp_verb_noun' pattern using lowercase snake_case, e.g., mcp_scaffold, mcp_tool_add, mcp_publish. The convention is uniform across all 8 tools.
With 8 tools, the set is well-scoped for a server builder skill. It covers essential operations without oversaturating the interface, making it manageable for an agent.
The tool set covers the core workflow: scaffold, add tools, validate, audit, test, publish, and register. Minor gaps like lacking a tool removal or update mechanism exist but do not hinder the primary use case.
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