Test your agent on hundreds of different people.
Agents fail on the users you didn’t imagine. Get varied simulated users, each with a stable personality and an id that brings them back for a replay.
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Aminah Hussain
Age 34City LondonJob Retail Assistant
# Built from one Mockfolk persona: g3mkk6o3pgz467mz7ze3baml.0You are Aminah Hussain, 34, a retail assistantat Oakham Trading in London (Putney).You live in a household of 4. You enjoy yoga and lawn bowls.Personality: energetic, driven and endlessly curious. openness 55 · conscientiousness 67 extraversion 72 · agreeableness 31 neuroticism 52You are contacting customer support about a delayed order.The prompt template is an example; you write your own. Every value in it comes from one persona. Real output from Mockfolk engine v1 (preview). All people are fictional.
Simulated users you can rely on.
Variety that looks like a real customer base
census-weighted mix · IN, US, GB
People follow each country’s mix of places, ages and jobs, from factory workers in Hyderabad to retail assistants in Gloucester, so your test set is not forty software engineers called Alex.
A personality that holds
Big Five scores + a style line
Each person carries openness, conscientiousness, extraversion, agreeableness and neuroticism scores and a plain-language style that come back unchanged with the person. Turn them into a system prompt for your user simulator.
Replay any failure
persona id = spec + index
When conversation 412 goes wrong, its user is one id away. The same id always returns the same person, pinned to the engine and data-pack versions it was made with.
People around a person
friends · coworkers
Ask for a persona’s friends or coworkers to test agents that handle households, teams or referrals. The links are deterministic and go both ways.
Memory and a life that grows roadmap
not available yet
Chat personas with memory, living personas with a timeline, and personas generated from a support ticket or a landing page are planned. They are not part of the early-access build.
One id. The same user, every run.
Commit seeds alongside your eval suite. Every night’s run talks to the same people, so a score change means your agent changed, not your test users.
# 500 different users for tonight's eval run, the same 500 every nightmockfolk new --country IN --count 250 --seed 2026mockfolk new --country US --count 150 --seed 2026mockfolk new --country GB --count 100 --seed 2026# Conversation 1 failed. Fetch the same user to replay it.GET /v1/personas/g3mkk6o3pgz467mz7ze3baml.0 { "id": "g3mkk6o3pgz467mz7ze3baml.0", "identity": { "given_name": "Aminah", "family_name": "Hussain", "age": 34 }, "personality": { "neuroticism": 52, "style": "energetic, driven and endlessly curious" }, "meta": { "engine_version": "v1", "pack_version": "2026-11" }}What is Mockfolk?
Mockfolk is a hosted API and command-line tool that generates realistic fictitious people for testing AI agents and for developer test data. Give it constraints such as a country, a city, an age range, an occupation or a latitude and longitude, and it fills in the rest consistently: name (in local script where relevant), address, contact details, job, income band, personality and a short backstory. The same request with the same seed, or the same persona id, always returns the same person.
What is a simulated user?
A simulated user is a fictional customer that a language model role-plays to test your agent or chatbot. Mockfolk supplies the person behind the role: name, place, job, household, hobbies and Big Five personality scores you turn into a system prompt, plus an id that returns the same person for every replay.
How many simulated users can I generate?
Up to 1,000 people per call, from the India, US and UK data packs. Commit the seed with your eval suite and every run talks to the same population, so score changes come from your agent, not from new test users.
Bring your agent. We’ll bring the people.
Mockfolk is in private beta. Leave your email and we’ll write once, when your API key is ready.