FAQ: Setup and Operation¶

Questions about running an exchange beyond the first start: seed quotes, the scheduler, watching the message bus, participant allowlists, and where the configuration and data files live. The first-day questions are in the Quick Start Guide's FAQ & Common Mistakes; questions about orders and positions are in the Participant Guide's FAQ: Orders, Sessions and Positions.

Starting the exchange¶

Why did the seed MM quote disappear after the second day?¶

By default, market_maker_quotes entries have seed_once: true. This means the seed is skipped whenever that market maker already has a live quote on the symbol that was restored from the previous run. A quote that was traded away or that expired is not restored, so its seed fires again; otherwise the real market maker is expected to keep submitting its own quotes.

To inject the seed on every startup (e.g. for a repeatable classroom demo):

market_maker_quotes:
  - gateway_id: MM01
    bid_price: 149.00
    ask_price: 151.00
    bid_qty: 500
    ask_qty: 500
    tif: DAY
    seed_once: false    # inject on every startup

To force a day-1 re-injection without changing the config:

rm data/book_stats.json    # or $EDUMATCHER_DATA_DIR/book_stats.json

Why did `pm-scheduler` exit immediately?¶

Because no configuration is deployed. The scheduler exits with a fatal error rather than falling back to its built-in default times — running a timetable the engine has never seen is worse than not starting at all.

pm-config-deploy engine_config.yaml

Seeing what is happening¶

How do I see what messages are flowing between processes?¶

Run pm-audit --terminal in a separate window. It subscribes to all ZeroMQ messages and prints them to stdout, giving a full real-time trace of every event in the system.

Participants¶

Why is my order rejected with "Gateway not authenticated"?¶

Your gateway ID is not in the engine's allowlist. Gateway IDs must be pre-configured in engine_config.yaml under participants:

participants:
    - id: GW01
      role: TRADER
      description: My first trader

Deploy the configuration (pm-config-deploy) and restart the engine after editing it.

Configuration and data files¶

The engine says it cannot find its configuration. Where should the file be?¶

In exactly one place, always:

<EDUMATCHER_DATA_DIR>/ref_data/engine_config.json

Mode	Data directory
pipx installed	`~/.local/share/edumatcher`
Source checkout	`<repo>/src/data/`
Either	`EDUMATCHER_DATA_DIR`, if set

The message means nothing has been deployed there yet. Install a configuration and the error goes away:

pm-config-deploy ~/my-session/engine_config.yaml
pm-config-deploy --show        # print the path it deployed to

There is no --config flag and no EDUMATCHER_CONFIG variable. Both used to exist, and the reason they no longer do is that they let one process be started against a configuration the rest of the exchange had never seen — the resulting symptom (a gateway reporting no instruments while the engine happily traded ten) gave no hint of the cause.

Where are my data files stored?¶

Data files (gtc_orders.json, stats.db, audit.log, etc.) go to:

Mode	Data directory
pipx installed	`~/.local/share/edumatcher`
Source checkout	`<repo>/src/data/`
Either	`EDUMATCHER_DATA_DIR` environment variable (highest priority)

To isolate two sessions from each other, run each in its own directory and set EDUMATCHER_DATA_DIR to a different path:

export EDUMATCHER_DATA_DIR=~/sessions/morning
pm-engine