removes mcp

.github/workflows/tests.yaml

@@ -46,7 +46,11 @@ jobs:
 
       - name: Upload coverage to Codecov
         if: success() && github.repository_owner == 'withtwoemms'
-        run: bash <(curl -s https://codecov.io/bash) -t ${{ secrets.CODECOV_TOKEN }}
+        uses: codecov/codecov-action@v5
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: coverage.xml
+          fail_ci_if_error: false
 
       - name: Archive coverage report
         if: always()
@@ -61,6 +65,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v5
+        with:
+          submodules: true
 
       - name: Install uv
         uses: astral-sh/setup-uv@v5

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "docs/external/ucon-tools"]
+	path = docs/external/ucon-tools
+	url = https://github.com/withtwoemms/ucon-tools.git

CHANGELOG.md

@@ -7,6 +7,22 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.9.4] - 2026-02-28
+
+### Changed
+
+- MCP subpackage extracted to [ucon-tools](https://github.com/withtwoemms/ucon-tools) (#212)
+  - Install MCP server via `pip install ucon-tools[mcp]`
+  - Core ucon package no longer has MCP dependencies
+  - Namespace package support via `pkgutil.extend_path()` enables coexistence
+
+### Removed
+
+- `ucon.mcp` subpackage (moved to ucon-tools)
+- `ucon-mcp` CLI entry point (now in ucon-tools)
+- `mcp` optional dependency
+- MCP documentation (moved to ucon-tools, sourced via submodule)
+
 ## [0.9.3] - 2026-02-26
 
 ### Added
@@ -438,7 +454,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Initial commit
 
 <!-- Links -->
-[Unreleased]: https://github.com/withtwoemms/ucon/compare/0.9.3...HEAD
+[Unreleased]: https://github.com/withtwoemms/ucon/compare/0.9.4...HEAD
+[0.9.4]: https://github.com/withtwoemms/ucon/compare/0.9.3...0.9.4
 [0.9.3]: https://github.com/withtwoemms/ucon/compare/0.9.2...0.9.3
 [0.9.2]: https://github.com/withtwoemms/ucon/compare/0.9.1...0.9.2
 [0.9.1]: https://github.com/withtwoemms/ucon/compare/0.9.0...0.9.1

Makefile

@@ -58,7 +58,7 @@ ${UV_VENV}: ${UV_INSTALLED}
 
 ${DEPS_INSTALLED}: pyproject.toml uv.lock | ${UV_VENV}
 	@echo "${GREEN}Syncing dependencies into ${UV_VENV}...${RESET}"
-	@UV_PROJECT_ENVIRONMENT=${UV_VENV} uv sync --python ${PYTHON} --extra test --extra pydantic --extra mcp
+	@UV_PROJECT_ENVIRONMENT=${UV_VENV} uv sync --python ${PYTHON} --extra test --extra pydantic
 	@touch ${DEPS_INSTALLED}
 
 .PHONY: venv
@@ -74,7 +74,7 @@ install-test: ${UV_VENV}
 .PHONY: install
 install: ${UV_VENV}
 	@echo "${GREEN}Installing with all extras into ${UV_VENV}...${RESET}"
-	@UV_PROJECT_ENVIRONMENT=${UV_VENV} uv sync --python ${PYTHON} --extra test --extra pydantic --extra mcp
+	@UV_PROJECT_ENVIRONMENT=${UV_VENV} uv sync --python ${PYTHON} --extra test --extra pydantic
 
 # --- Testing ---
 .PHONY: test

README.md

@@ -49,7 +49,7 @@ With extras:
 
 ```bash
 pip install ucon[pydantic]  # Pydantic v2 integration
-pip install ucon[mcp]       # MCP server for AI agents
+pip install ucon-tools[mcp] # MCP server for AI agents (separate package)
 ```
 
 ---
@@ -108,14 +108,18 @@ print(m.model_dump_json())
 
 ### MCP Server for AI Agents
 
-Configure in Claude Desktop:
+Install `ucon-tools` and configure in Claude Desktop:
+
+```bash
+pip install ucon-tools[mcp]
+```
 
 ```json
 {
   "mcpServers": {
     "ucon": {
       "command": "uvx",
-      "args": ["--from", "ucon[mcp]", "ucon-mcp"]
+      "args": ["--from", "ucon-tools[mcp]", "ucon-mcp"]
     }
   }
 }
@@ -128,7 +132,7 @@ AI agents can then convert units, check dimensions, and perform factor-label cal
 ## Features
 
 - **Physical constants** — CODATA 2022 values with uncertainty propagation (`E = m * c**2`)
-- **Custom constants** — Define domain-specific constants with uncertainty propagation via MCP or Python API
+- **Custom constants** — Define domain-specific constants with uncertainty propagation
 - **String parsing** — `parse("9.81 m/s^2")` with uncertainty support (`1.234 ± 0.005 m`)
 - **Dimensional algebra** — Units combine through multiplication/division with automatic dimension tracking
 - **Scale prefixes** — Full SI (kilo, milli, micro, etc.) and binary (kibi, mebi) prefix support

ROADMAP.md

@@ -47,14 +47,15 @@ ucon is a dimensional analysis library for engineers building systems where unit
 | v0.9.1 | Logarithmic Units | Complete |
 | v0.9.2 | MCP Constants Tools | Complete |
 | v0.9.3 | Natural Units + MCP Session Fixes | Complete |
+| v0.9.4 | MCP Extraction | Complete |
 | v0.10.0 | Scientific Computing | Planned |
 | v1.0.0 | API Stability | Planned |
 
 ---
 
-## Current Version: **v0.9.3** (complete)
+## Current Version: **v0.9.4** (complete)
 
-Building on v0.9.2 baseline:
+Building on v0.9.3 baseline:
 - `ucon.basis` (`Basis`, `BasisComponent`, `Vector`, `BasisTransform`, `BasisGraph`, `ConstantAwareBasisTransform`)
 - `ucon.bases` (standard bases: `SI`, `CGS`, `CGS_ESU`, `NATURAL`; standard transforms including `SI_TO_NATURAL`)
 - `ucon.dimension` (`Dimension` as frozen dataclass backed by basis-aware `Vector`)
@@ -63,7 +64,6 @@ Building on v0.9.2 baseline:
 - `ucon.graph` (`ConversionGraph`, default graph, `get_default_graph()`, `using_graph()`, cross-basis conversion)
 - `ucon.units` (SI + imperial + information + angle + ratio units, callable syntax, `si` and `imperial` systems, `get_unit_by_name()`)
 - `ucon.pydantic` (`Number` type for Pydantic v2 models)
-- `ucon.mcp` (`SessionState`, `DefaultSessionState` for injectable session management)
 - Callable unit API: `meter(5)`, `(mile / hour)(60)`
 - `Number.simplify()` for base-scale normalization
 - Pseudo-dimensions: `ANGLE`, `SOLID_ANGLE`, `RATIO`, `COUNT` with semantic isolation
@@ -77,9 +77,8 @@ Building on v0.9.2 baseline:
 - Quantity string parsing: `parse("1.234 ± 0.005 m")` → `Number` with uncertainty
 - Physical constants: `Constant` class with CODATA 2022 values and uncertainty propagation
 - Logarithmic units: pH with concentration dimension, dBm, dBW, dBV, dBSPL
-- MCP constants tools: `list_constants()`, `define_constant()` for AI agent access
 - Natural units: `NATURAL` basis with c=ℏ=k_B=1, `ConstantAwareBasisTransform` for non-square transforms
-- MCP session persistence: lifespan-scoped session state across tool calls
+- Namespace package support: `pkgutil.extend_path` enables coexistence with ucon-tools
 
 ---
 
@@ -213,6 +212,9 @@ Building on v0.9.2 baseline:
 
 **Theme:** AI agent integration.
 
+> **Note:** MCP functionality moved to [ucon-tools](https://github.com/withtwoemms/ucon-tools) in v0.9.4.
+> Install via `pip install ucon-tools[mcp]`.
+
 - [x] MCP server exposing unit conversion tools
 - [x] `convert` tool with dimensional validation
 - [x] `list_units`, `list_scales`, `list_dimensions` discovery tools
@@ -655,6 +657,24 @@ Prerequisite for factor-label chains with countable items (tablets, doses).
 
 ---
 
+## v0.9.4 — MCP Extraction (Complete)
+
+**Theme:** Separate MCP tooling into ucon-tools package.
+
+- [x] Extract `ucon.mcp` subpackage to `ucon-tools` repository
+- [x] Add `pkgutil.extend_path()` for namespace package coexistence
+- [x] Remove MCP optional dependency and entry point from pyproject.toml
+- [x] Update documentation to reference `ucon-tools[mcp]` for MCP features
+- [x] MCP docs moved to ucon-tools (sourced via git submodule)
+
+**Outcomes:**
+- Core ucon package has no MCP dependencies (simpler install, broader compatibility)
+- MCP tooling available via `pip install ucon-tools[mcp]`
+- Namespace package allows both packages to coexist under `ucon.*`
+- ucon-tools can iterate independently on AI agent features
+
+---
+
 ## v0.10.0 — Scientific Computing
 
 **Theme:** NumPy and DataFrame integration.

docs/guides/custom-units-and-graphs.md

@@ -3,7 +3,7 @@
 ucon's unit system is extensible. You can define domain-specific units and conversions for aerospace, medicine, finance, or any specialized field.
 
 !!! tip "MCP Users"
-    For AI agent use cases, see [Custom Units via MCP](mcp-server/custom-units.md).
+    For AI agent use cases, see [Custom Units via MCP](../external/ucon-tools/docs/guides/mcp-server/custom-units.md).
 
 ## Unit Definition
 

docs/guides/index.md

@@ -4,9 +4,9 @@ Task-oriented guides for common use cases.
 
 ## MCP Server
 
-- **[Overview](mcp-server/index.md)** - Setup and available tools
-- **[Custom Units](mcp-server/custom-units.md)** - Define domain-specific units at runtime
-- **[Registering Formulas](mcp-server/registering-formulas.md)** - Expose dimensionally-typed calculations to agents
+- **[Overview](../external/ucon-tools/docs/guides/mcp-server/index.md)** - Setup and available tools
+- **[Custom Units](../external/ucon-tools/docs/guides/mcp-server/custom-units.md)** - Define domain-specific units at runtime
+- **[Registering Formulas](../external/ucon-tools/docs/guides/mcp-server/registering-formulas.md)** - Expose dimensionally-typed calculations to agents
 
 ## Integration Guides