Resale Goliath

I built this around a resale workflow question: how can software agents help with inventory, pricing, and listings without receiving the marketplace's credentials or unrestricted execution power? Goliath puts typed services, durable jobs, and account policy between a proposal and an external action.

Working backend, still under development. FastAPI, PostgreSQL, SQLAlchemy/Alembic, a Typer CLI, and MCP are implemented. Offline tests exercise the workflow and failure paths; live marketplace behavior is a separate, opt-in test layer.

The interesting engineering

• Jobs survive process restarts: workers claim leases, heartbeat, retry, cancel, and recover work through versioned state transitions.
• Inventory, comparables, pricing, drafts, and approvals use typed workflows rather than arbitrary SQL or generic account mutation.
• Human API principals, MCP service principals, workers, and marketplace accounts have distinct identities and scopes.
• Marketplace writes pass through policy, idempotency, account health, circuit breakers, emergency stops, and read-back verification.
• Marketplace sessions stay behind the broker and adapters. Agent subprocesses receive an allowlisted environment.

Boundaries

flowchart TB
    ENTRY["CLI / API / MCP"] --> SERVICE["Typed services and policy"]
    SERVICE --> DB["PostgreSQL and audit events"]
    SERVICE --> JOB["Durable jobs and leased workers"]
    JOB --> AGENT["Configured agent subprocess"]
    SERVICE --> GATE["Marketplace gateway"]
    GATE --> ADAPTER["Session broker and typed adapter"]

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The MCP interface has no generic shell, SQL, cookie, or browser-profile tool. Configured coding agents can run commands inside their allowed workspace; permissions passed to an agent are not an OS sandbox. The adapter, host permissions, and deployment isolation still matter.

Leases coordinate claims and completion; they are not an exactly-once guarantee for external effects. Idempotency and verification address that separate problem.

Run locally

Python 3.11+ and PostgreSQL are required for the normal application. SQLite is used only by the isolated test layer.

python3 -m venv .venv
source .venv/bin/activate
pip install -e '.[dev]'
pip install 'psycopg[binary]>=3,<4'

cp config/agents.example.yaml config/agents.yaml
export GOLIATH_CONFIG="$PWD/config/agents.yaml"
export GOLIATH_DATABASE_URL='postgresql+psycopg://user:password@localhost/resale_goliath'
# Create that database and edit workspace_roots/agent commands before proceeding.
alembic upgrade head
goliath agent list
goliath agent doctor

Keep credentials in the application environment, outside agent workspaces. Start the API with python -m goliath.api_runner. Example API, worker, and scheduler service units live in systemd/.

Tests and code worth reading

pytest
ruff check .

Default tests exclude sandbox and live marketplace operations. Offline SQLite coverage does not establish PostgreSQL locking behavior or live adapter reliability.

Path	What to inspect
goliath/orchestration/	Worker leases, job lifecycle, retries, and recovery
goliath/marketplace/gateway.py	Policy, idempotency, breakers, and receipts
goliath/marketplace/broker.py	Session boundary
goliath/mcp/	Bounded tools and scoped principals
tests/	Lifecycle, supervisor, API, domain, and marketplace tests
docs/ebay-adapter-design.md	eBay adapter design and limitations

Browser-backed adapters need pip install -e '.[browser]' and playwright install chromium. They remain subject to account policy and marketplace-specific behavior. This is not a claim of production readiness across every marketplace.

The repository's older name is Resale-Monster; the application/package is resale-goliath / goliath.