Synopsis - .NET Workspace Dependency & Blast-Radius Explorer

Static analysis tool that scans .NET workspaces via Roslyn, builds a dependency graph, and answers blast-radius and breaking-change queries. Supports both one-shot CLI use and long-running daemon mode for multi-repo workspaces.

Requirements

No SDK or manual installation needed. The detect script auto-downloads the correct binary on first use.

External dependencies for auto-download:

• macOS/Linux: curl (pre-installed) or wget
• Windows: PowerShell 5+ (built-in System.Net.Http)

Install (optional - build from source)

Only needed if you want to rebuild or no GitHub Release is available. Requires .NET 10+ SDK.

Bash (Linux/macOS):

./skills/dotnet-techne-synopsis/scripts/install.sh

PowerShell (Windows):

.\skills\dotnet-techne-synopsis\scripts\install.ps1

When to use this skill

Use when the user asks to:

• Analyze blast radius of a code change
• Map dependencies across .NET repos
• Find what endpoints/services are affected by a change
• Trace call chains from controller to database
• Review cross-repo boundaries
• Audit ambiguous/unresolved dependencies
• Compare architecture between two snapshots (diff)
• Classify breaking changes between two snapshots
• Scope a PR's impact via git diff
• Run a persistent daemon serving multiple repos under one graph
• Find all callers of an HTTP endpoint across repos (endpoint_callers)
• Find which services depend on a NuGet package and at what version (package_dependents)
• Find HTTP endpoints that write to a specific database table (table_entry_points)
• Get a service-to-service HTTP call dependency map (repo_dependency_matrix)

Workflow

Step 0: Detect tool

Bash:

./skills/dotnet-techne-synopsis/scripts/detect-tool.sh

PowerShell:

.\skills\dotnet-techne-synopsis\scripts\detect-tool.ps1

Step 1: Scan a workspace

synopsis scan /path/to/workspace -o graph.json

This produces graph.json containing all nodes (repos, projects, controllers, methods, endpoints, HTTP clients, DB contexts, entities, tables, NuGet packages) and edges (calls, injects, implements, cross-repo, depends-on-package, etc.).

Step 2: Query the graph

Blast radius of a symbol:

synopsis query symbol --fqn "OrdersController" --blast-radius --graph graph.json
synopsis query symbol --fqn "IOrderRepository" --blast-radius --direction upstream --graph graph.json

Impact analysis:

synopsis query impact --node "OrdersController" --direction downstream --graph graph.json --json
synopsis query impact --node "Orders" --direction upstream --graph graph.json --json

Find paths between nodes:

synopsis query paths --from "OrdersController" --to "Orders" --graph graph.json --json

Audit ambiguous edges:

synopsis query ambiguous --graph graph.json --json

Step 3: Git-aware analysis

Scope analysis to files changed in a PR:

synopsis git-scan /path/to/workspace --base main --json

Step 4: Diff two scans

Compare architecture before/after a change:

synopsis diff before.json after.json --json

Step 5: Breaking-change classification

Classify typed breaking changes between two snapshots:

synopsis breaking-diff before.json after.json --json
synopsis breaking-diff before.json after.json -o report.json

Produces typed BreakingChangeKind values:

• Paired changes: NugetVersionBump, EndpointRouteChange, EndpointVerbChange, ApiSignatureChange, TableRename
• Removals: PackageRemoved, EndpointRemoved, ApiRemoved, TableRemoved

Heuristic pairings carry Ambiguous certainty; unmatched nodes flow into removal kinds.

Step 6: MCP daemon mode (multi-repo)

For persistent AI agent integration over multiple repositories. The daemon holds a CombinedGraph that merges per-repo scans in memory and persists state to disk.

stdio (one-shot, single repo):

synopsis mcp --root /path/to/workspace
synopsis mcp --graph graph.json

Unix socket daemon (multi-repo, persistent):

synopsis mcp --root /path/to/workspace --socket /tmp/synopsis.sock --state-dir ~/.synopsis/workspace

TCP daemon:

synopsis mcp --root /path/to/workspace --tcp localhost:5100

State is persisted to --state-dir and restored on restart. On restart, repos are loaded from disk without re-scanning; use reindex_all to force a fresh scan of all known repos.

Quick Reference

# === One-shot scan and query ===
synopsis scan /workspace -o graph.json                              # Scan
synopsis query symbol --fqn "OrdersController" --blast-radius       # Blast radius
synopsis query impact --node "Orders" --direction upstream --json   # Upstream impact
synopsis git-scan /workspace --base main --json                     # PR impact
synopsis breaking-diff before.json after.json --json                # Breaking changes

# === Export formats ===
synopsis export json /workspace -o graph.json
synopsis export csv /workspace -o output/
synopsis export jsonl /workspace -o graph.jsonl

# === Daemon (multi-repo) ===
synopsis mcp --root /workspace --socket /tmp/synopsis.sock --state-dir ~/.synopsis/ws

# === All commands support --json for machine-readable output ===
synopsis scan /workspace --json
synopsis query impact --node X --json

Output Contract

When --json is used, stdout contains a single JSON envelope:

{"command":"query impact","ok":true,"result":{...},"ms":142}

All diagnostics and progress go to stderr. stdout is always machine-readable when --json is specified.

MCP Tools Available

When running in MCP mode (synopsis mcp), the following tools are exposed:

HTTP Cross-Service Resolution

Synopsis traces HTTP calls across microservice boundaries. For best resolution accuracy:

• Use `IHttpClientFactory` with named clients — the client name is the strongest signal for matching
• Put base URLs in appsettings with descriptive keys — Services:CatalogApi:BaseUrl not generic ApiUrl
• Name repos and projects consistently — CatalogClient auto-matches repo catalog-api and project Catalog.Api

See http-resolution.md for the full guide on supported patterns, appsettings configuration, service-affinity matching, certainty levels, and recommendations.

Notes

• Synopsis uses Roslyn MSBuildWorkspace for semantic analysis — it understands DI registration, interface dispatch, call graphs, and EF Core mappings
• The tool targets .NET Core/.NET 5+ projects only (no .NET Framework 4.x support)
• First scan of a large workspace takes 15–60s; subsequent queries on a loaded graph.json are instant
• MCP daemon mode scans once at startup (or on reindex_* calls), then serves queries with no re-scan overhead
• NuGet packages are first-class graph nodes (Package type, DependsOnPackage edges) from v1.4.0
• Graph node IDs are SHA256-based and stable across scans of the same codebase