ed-tech-system-mcp

Domain-Driven MCP (Model Context Protocol) server for ed-tech workflows. The server exposes validated MCP tools backed by LangGraph agents, Supabase document retrieval, web search, and YouTube video discovery — all organized with Clean Architecture and DDD.

What this project does

External MCP clients call MCP tools that validate input with Pydantic, delegate to application workflows and LangGraph agents, and reach external systems through domain ports implemented in the infrastructure layer.

MCP tools

All tool handlers are wrapped with MCP tool caching (when enabled), per-tool latency logging, and domain error mapping at the protocol boundary.

Integrations

Adapter status: Infrastructure adapters are scaffolded with domain guards and exception taxonomy; full HTTP implementations (BL-022) are deferred. MCP tools exercise the workflow and port contracts through the composition root.

Related MCP server: mcp-canon

Architecture

The codebase follows Clean Architecture with five layers under src/mcp_server/:

entrypoint  →  interface  →  application  →  domain  ←  infrastructure
(main.py)      (MCP tools)   (agents)        (ports)     (adapters)

Read next: ARCHITECTURE.md for layer rules, patterns, and anti-patterns. AGENTIC_ARCHITECTURE.md for LLM wiring, tool taxonomy, and agent flows. OBSERVABILITY.md for the local LangGraph workflow UI, execution replay, and trace debugging.

Quick start

Prerequisites

• Python 3.12 (see requires-python in pyproject.toml)

• uv — environment and dependency manager

• Doppler CLI (recommended for secrets) or a local gitignored .env

Install

uv python install 3.12
uv sync --all-groups

Configure secrets

Secrets never enter git. Use Doppler (team) or a local .env (solo dev).

doppler login
./scripts/doppler/setup-local.sh
./scripts/doppler/bootstrap-from-env-example.sh   # first time only — uploads placeholders
# Fill real values in the Doppler dashboard → ed-harness-system

Required variables: APP_ENV, SUPABASE_URL, SUPABASE_SERVICE_ROLE_KEY, YOUTUBE_API_KEY.

Optional: GROQ_API_KEY (only when an LLM path is invoked — lazy-init at first use), TAVILY_API_KEY, LOG_LEVEL (applied at bootstrap via configure_logging()), CACHE_ENABLED + REDIS_URL (production).

See ENVIRONMENT_SETUP.md for the full secrets workflow.

Run the MCP server

# With Doppler
doppler run -- uv run mcp-server

# With local .env (APP_ENV=development)
uv run mcp-server

Run the workflow UI (optional)

Local dev UI for inspecting workflow graphs, running test executions, and replaying traces:

./scripts/dev/run-workflow-ui.sh

API: http://127.0.0.1:8877 (default) · React dev server: http://127.0.0.1:4173

Graph visualization — retry loops and parallel branches are rendered on the canvas:

Trace replay & debugging — after a run, scrub through each node, inspect failures, and read LLM I/O:

Node I/O inspector — per-step state snapshots, validation errors, and LLM prompts/raw output:

See OBSERVABILITY.md for graph replay, node I/O inspection, and trace API details.

To refresh README screenshots after UI changes:

./scripts/dev/run-workflow-ui.sh   # in one terminal
npx -p playwright node scripts/dev/capture-ui-screenshots.mjs   # in another

Development

Day-to-day commands

uv sync --frozen              # after pulling lockfile changes
uv run mcp-server             # start server
uv run ruff check src/        # lint
uv run ruff format --check src/
uv run mypy src/              # type check
uv run pytest                 # tests (143 cases as of 2026-07-21)

Engineering backlog

Audit findings are triaged into backlog/BACKLOG.md (RICE-ranked, traceable to changelog audits). As of 2026-07-21: 23 done, 6 deferred (adapter HTTP implementation, profiling, trace IDs).

Add dependencies

uv add some-package           # runtime
uv add --group dev some-tool  # dev only

Do not use pip install in this repo — it bypasses the lockfile.

Quality gates (CI parity)

uv sync --frozen --all-groups
uv run ruff check src/
uv run mypy src/
npm run lint:architecture   # layer imports + boundary patterns (also runs on git push)
uv run pytest

Git hooks: Husky pre-commit runs public-repo safety checks (sensitive files, tracked leaks, secret scanners); pre-push re-checks tracked safety, scans pushed commits for secret content, then runs architecture lint — neither blocks the other tier.

Run quality-gate commands from the repository root (ed-tech-system-mcp/), not ui/. The same scripts are also available inside ui/ via npm run hooks:test and npm run lint:architecture.

Project layout

.
├── src/mcp_server/          # Application source (layered)
├── tests/                   # pytest suites
├── ui/                      # React workflow graph UI
├── scripts/
│   ├── doppler/             # Secret bootstrap and local setup
│   ├── hooks/               # Husky pre-commit guards
│   └── dev/                 # Dev tooling (workflow UI launcher)
├── docs/
│   └── assets/              # README screenshots (workflow UI)
├── ARCHITECTURE.md          # Layer boundaries and patterns
├── AGENTIC_ARCHITECTURE.md  # Agent graphs and tool orchestration
├── OBSERVABILITY.md         # Workflow UI, trace replay, debugging
└── ENVIRONMENT_SETUP.md     # uv, secrets, CI, MCP client config

Documentation index

See the documentation matrix at the end of this file for canonical docs and changelog artifacts.

MCP client integration

Register the server in your MCP host using the project interpreter:

{
  "mcpServers": {
    "ed-tech-system": {
      "command": "doppler",
      "args": ["run", "--", "uv", "--directory", "/absolute/path/to/ed-tech-system-mcp", "run", "mcp-server"]
    }
  }
}

Alternative patterns (local .env, uv launcher) are in ENVIRONMENT_SETUP.md § MCP client integration.

Documentation matrix

Read the minimum doc set for your task. Do not load everything.

Canonical docs (repo root)

Conflict resolution: ARCHITECTURE.md wins on layer boundaries; AGENTIC_ARCHITECTURE.md wins on orchestration semantics.

Engineering backlog

Changelog memory (changelog/{DATE}/{LAYER}/)

Local engineering memory for investigations, implementations, reviews, audits, and test homologation (gitignored — not published).

Pairing: IMPLEMENTATION{N} ↔ INVESTIGATION{N}; CODE_REVIEW{N} ↔ same {N}.

Quick routing

Code in a layer?        → ARCHITECTURE.md (+ AGENTIC_ARCHITECTURE.md if agents/tools/LLM)
Workflow UI / traces?   → OBSERVABILITY.md
Environment / CI?       → ENVIRONMENT_SETUP.md
Secrets / Doppler?      → ENVIRONMENT_SETUP.md § Secrets & safety
Tests / merge gate?     → pytest + quality gates in ENVIRONMENT_SETUP.md
Audits / cleanup?       → backlog/BACKLOG.md

License

MIT