Personas & Blueprints
A persona is a fictional identity with a coherent life story. A blueprint is the concrete data that persona generates across all surfaces — database rows, API responses, MCP tool outputs.
Pre-built personas ship as JSON files and work offline without LLM calls. Custom personas are generated by the Blueprint Engine (Pro), which uses an LLM to create a coherent persona then a deterministic expander to produce consistent data across all configured surfaces.
Available pre-built personas
| Persona | Domain | Description |
|---|---|---|
finance-alex | Fintech | 32, fintech PM, $85K, 3 bank accounts, active trader, Jira power user |
freelancer-maya | Freelance | 28, freelance designer, multi-currency income, Stripe/PayPal/invoicing |
college-student | Education | 20, college junior, part-time work, student loans, budgeting |
Adapters
Adapters are Mimic’s plugin system. There are two types:
Database adapters connect to real databases and seed them with persona data. They implement DatabaseAdapter with seed() and clean() methods.
API mock adapters register Fastify routes that simulate real API endpoints. They implement ApiMockAdapter with registerRoutes() and getEndpoints() methods.
Mock Server
The mock server is a Fastify instance that:
- Loads all configured adapters from
mimic.json - Calls each adapter’s
registerRoutes()to mount route handlers - Serves HTTP requests, routing by path prefix to the correct adapter
- Provides CORS headers for browser-based agent testing
State Store
The state store is a per-adapter in-memory key-value store that holds seeded data during a mock server session.
| Method | Description |
|---|---|
set(collection, id, data) | Store a record |
get(collection, id) | Retrieve by ID |
list(collection) | List all records in a collection |
filter(collection, predicate) | Query records by predicate function |
update(collection, id, partial) | Partial update a record |
delete(collection, id) | Remove a record |
The state store resets when the server restarts. For stateful testing across sessions, the Pro tier offers session persistence.