Model Config Reference

Model implementation has two layers:

1. Console-global model pool in ~/.downcity/downcity.db (SQLite)
2. Project-local model.primary in each agent downcity.json

1) Persistence layout

Console-global model pool:

• file: ~/.downcity/downcity.db
• tables: model_providers, models
• write entrypoint: city model ...

Project-local binding:

• file: <project>/downcity.json
• field: model.primary

2) Write flow

1. city model ...
   writes provider/model records into ~/.downcity/downcity.db

2. Console UI model switch
   updates current agent downcity.json -> model.primary

3. city agent create
   selects a model id from console pool and writes model.primary

3) Read flow at runtime

{
  "model": {
    "primary": "default"
  }
}

primary must reference an existing model id in SQLite, otherwise startup fails.

4) Encryption behavior

Provider apiKey is not stored in plaintext:

• algorithm: AES-256-GCM field-level encryption
• key priority: DC_MODEL_DB_KEY env var > ~/.downcity/console/model-db.key
• DB field: api_key_encrypted

5) Commands

Manage model pool globally:

city model list
city model get model fast

Bind agent to a model ID:

city config set model.primary fast

6) Apply changes

Restart agent after model changes:

city agent restart .

Related docs

• downcity.json Reference