Mason MCP server
{
"mcpServers": {
"adrianczuczka-mason": {
"command": "npx",
"args": [
"-y",
"mason-context@latest"
],
"env": {
"GITHUB_TOKEN": "ghp_..."
}
}
}
}{
"mcpServers": {
"adrianczuczka-mason": {
"command": "npx",
"args": [
"-y",
"mason-context@latest"
],
"env": {
"GITHUB_TOKEN": "ghp_..."
}
}
}
}{
"mcpServers": {
"adrianczuczka-mason": {
"command": "npx",
"args": [
"-y",
"mason-context@latest"
],
"env": {
"GITHUB_TOKEN": "ghp_..."
}
}
}
}{
"servers": {
"adrianczuczka-mason": {
"command": "npx",
"args": [
"-y",
"mason-context@latest"
],
"env": {
"GITHUB_TOKEN": "${input:github_token}"
}
}
},
"inputs": [
{
"id": "github_token",
"type": "promptString",
"description": "Github token",
"password": true
}
]
}{
"mcpServers": {
"adrianczuczka-mason": {
"command": "npx",
"args": [
"-y",
"mason-context@latest"
],
"env": {
"GITHUB_TOKEN": "ghp_..."
}
}
}
}file .mcp.json (in your project root)file claude_desktop_config.jsonfile ~/.cursor/mcp.jsonfile .vscode/mcp.jsonfile ~/.codeium/windsurf/mcp_config.jsoninstall npx -y mason-contextversion 0.18.0
What it does
Mason is an MCP server that captures and retrieves engineering decisions, architectural context, and codebase history for AI assistants working in Git repositories. It helps assistants avoid re-suggesting past mistakes and provides relevant file and decision context during coding tasks.
- Audit and review commits to check for undocumented decisions and missing historical context using `mason-audit` and `mason-review`.
- Record engineering decisions and constraints during incident resolution with `save_decision`, then retrieve them as proposals with file impact and test evidence on related tasks.
- Build and maintain a concept map of features and flows to files, verified by the assistant and used by Mason to provide relevant architectural context during code changes.
Tools this server exposes
| Tool | Does |
|---|---|
| mason_init | Runs audit and review checks on the repository and returns setup guidance for adding Mason instructions to project documentation. |
| get_context | Retrieves decisions matching the current task, including rationale, file impact, tests, and trust evidence from the decision store. |
| save_decision | Records a lesson or constraint learned from a real incident or resolved problem as a decision record. |
| review_decision | Marks a decision as accepted or reaffirmed by the team. |
| verify_snapshot | Spot-checks the concept map of features, flows, and file relationships. |
Before you enable it
An MCP server runs with whatever access you give it. Start with a development account rather than production, and check which tools the server exposes before you let an agent call them unattended.