Free & open source · Runs 100% on your machine

The simulator for conversations.

Practice interviews, negotiations, language, and difficult conversations with AI characters whose reactions evolve as you speak — all running locally on your computer. No account. No cloud. No telemetry.

Windows · macOS · Linux · Steam Deck  —  or build the Apache-2.0 source for free.

No cloud inference No account No telemetry No subscription

Practice the conversation before it matters.

Four official scenario packs ship free with every copy — openly licensed and yours to remix — with premium expansion packs available on Steam:

Job Interview Basics

Walk in ready.

  • Behavioral interview
  • Hostile executive
  • Blue-collar trade
  • Stretch role

Everyday Negotiation

Get to yes without giving in.

  • Used car
  • Apartment lease
  • Freelance scope
  • Customer-service refund

Language Café

Order the coffee in Spanish.

  • Spanish coffee shop
  • French hotel check-in
  • Japanese convenience store
  • English small talk

Difficult Conversations

Say the hard thing well.

  • Coworker feedback
  • Missed-deadline apology
  • Boundary with a friend
  • Ask for a raise

How a session works

  1. Choose a scenario

    Browse the library, read your player brief, and set the difficulty. Every scenario has goals, state variables, and events waiting to fire.

  2. Talk it out

    Type or speak. The character across the table pushes back, warms up, loses patience — its reactions evolve with every turn you take.

  3. Watch the state shift

    Live meters — credibility, composure, pressure — show the dynamic changing in real time. Say the wrong thing and you’ll see it.

  4. Debrief. Then run it again.

    A scored debrief shows what you said clearly, where you hedged, and the turning points. Adjust, rerun, improve. That’s the whole point.

Local-first is not a feature. It’s the architecture.

The conversations you most need to practice are exactly the ones you’d never type into someone else’s server. So there is no server.

WhatWhere it runs
Language modelYour machine — llama.cpp
Speech-to-textYour machine — whisper.cpp
Text-to-speechYour machine — Kokoro / sherpa-onnx
Transcripts & scoresYour disk — SQLite, never uploaded
TelemetryNowhere — none is built in

Don’t take our word for it

The code is open. And any time you like, one command runs a scripted conversation and confirms not a single byte left your machine:

npx convsim offline-smoke-test \
  packs/official/job-interview-basic

It exits with an error if any subsystem so much as tries to reach an external host.

Read the full privacy policy →

Have a look around

Scenario Library filtered by the search word "interview": the Job Interview Basics pack listing four scenario cards with summaries, rating, role, length, language, difficulty and tag chips, and a Launch button on each.
Scenario Library — search and filter installed packs
Conversation screen mid-session: the NPC panel reads Impressed and Listening, the transcript alternates player and NPC turns tagged with event flags, and seven NPC state meters sit below it — trust, patience, rapport, openness, objective_progress, conviction and preparation_score.
Conversation — live transcript, event flags, state meters
Session debrief scoring the session 53 out of 100 with a Player Exit badge, a six-dimension rubric scorecard, a telemetry panel with conversation metrics and a sparkline per state meter, and strengths that each cite the turn they came from.
Debrief — score, rubric scorecard, what to fix
Creator Workbench with a green "Pack is valid" banner, the pack list showing official packs and one editable local copy, that copy's file tree, and a YAML editor open on a scenario file.
Creator Workbench — build packs in YAML

Real captures from one playthrough on a local Qwen3 4B model — no mockups, no cloud.

Write your own scenarios. No code required.

A scenario pack is a folder of YAML files — the situation, the character, the scoring rubric, the safety rules. If you can describe a conversation, you can build one.

The built-in Creator Workbench lets you copy an official pack, edit, validate with one click, test in the browser, and export a shareable zip. Publish to Steam Workshop or hand the file to a friend.

scenario_id: ask_for_a_raise
title: The Salary Conversation
player_role:
  brief: Make the case for the raise
    you already deserve.
npc:
  ref: ../npcs/your_manager.yaml
state:
  variables:
    rapport:
      default: 50
      visibility: visible

Practice the conversation
before it matters.