The first public benchmark for AI child safety. Learn more at korabench.ai.
Overview
KORA measures the safety of AI models interacting with children across 8 risk categories, 25 individual risks, 3 age groups (7–9, 10–12, 13–17), and 10 child motivations. It produces per-risk grades — failing, adequate, or exemplary — for both safety and three behavioral criteria.
The benchmark uses a 3-stage pipeline: seed generation creates short scenario outlines from the risk taxonomy, scenario expansion turns each seed into a detailed test scenario with validation, and test runs execute multi-turn conversations and judge the results.
Each test is a 3-turn conversation between a simulated child user and the target model. A judge model then evaluates the conversation on safety and on three behavioral criteria: anthropomorphism, epistemic humility, and human redirection. Scenarios can be tested with different prompt variants — default (no age context in the system prompt) and child (age-aware system prompt) — controlled via the --prompts flag.
Prerequisites
Node.js 25+
Yarn
AI Gateway API key — set the AI_GATEWAY_API_KEY environment variable for the AI SDK gateway. Copy .env.example to .env and fill in your key.
Getting started
Install dependencies and build:
cp .env.example .env # then add your API key
yarn && yarn tsbuild
Run the benchmark with pre-built scenarios:
yarn kora run <target-model>
For example, to evaluate gpt-4o:
yarn kora run gpt-4o
Pipeline stages
generate-seeds
Generates a set of scenario seeds from the risk taxonomy.
yarn kora generate-seeds [model]
| Argument / Option | Description |
|---|---|
| [model] | Model to use for seed generation (default: gpt-5.2:high) |
| -o, --output <path> | Output JSONL file (default: data/scenarioSeeds.jsonl) |
| --seeds-per-task <count> | Seeds per risk/age/motivation combination (default: 8) |
expand-scenarios
Transforms seeds into fully fleshed-out scenarios with validation.
yarn kora expand-scenarios [model] [user-model]
| Argument / Option | Description |
|---|---|
| [model] | Model to use for scenario expansion (default: gpt-4o) |
| [user-model] | Model to use for generating the first user message (default: deepseek-v3.2) |
| -i, --input <path> | Input seeds JSONL file (default: data/scenarioSeeds.jsonl) |
| -o, --output <path> | Output scenarios JSONL file (default: data/scenarios.jsonl) |
run
Runs the benchmark against the target model.
yarn kora run <target-model> [user-model]
| Argument / Option | Description |
|---|---|
| <target-model> | Model to benchmark |
| [user-model] | Model to use for simulating the child user (default: deepseek-v3.2) |
| --judges <models> | Comma-separated judge models (default: gpt-5.2:high:limited) |
| -i, --input <path> | Input scenarios JSONL file (default: data/scenarios.jsonl) |
| -o, --output <path> | Output results JSON file (default: data/results.json) |
| --prompts <prompts> | Comma-separated prompt variants to test (default: default) |
When multiple judge models are specified, each judge independently evaluates every conversation. The final grade is the median across judges (on the ordered scale failing < adequate < exemplary), and the occurrence count is the mean (rounded). Per-judge results are stored in each test result for analysis.
All commands write to data/ by default. Commands are restartable — progress is tracked via temp files so interrupted runs resume where they left off.
Model configuration
Model registry (models.json)
Models are configured in a models.json file at the project root. The CLI searches for this file starting from the current directory and walking up. Each entry maps a model slug (used on the command line) to its configuration:
| Field | Required | Description |
|---|---|---|
| model | Yes | Provider/model identifier for the AI SDK gateway (e.g. openai/gpt-4o) |
| maxTokens | No | Maximum output tokens (default: 4000) |
| temperature | No | Sampling temperature |
| providerOptions | No | Provider-specific options passed through to the AI SDK |
Authentication is handled via the AI_GATEWAY_API_KEY environment variable.
Custom models
Model slugs that start with custom- bypass the AI SDK gateway and are routed to packages/cli/src/models/customModel.ts. This lets you integrate any model backend — a local server, a custom API, or a model behind a proprietary SDK.
To add a custom model, edit models/customModel.ts and implement the Model interface:
export async function createCustomModel(modelSlug: string, _scenario: Scenario): Promise<Model> {
return {
async getTextResponse(request) {
// request.messages contains the conversation (system, user, assistant messages).
// request.maxTokens and request.temperature are optional hints.
// Return the model's text response.
throw new Error(`Custom model "${modelSlug}" is not implemented.`);
},
async getStructuredResponse(request) {
// request.outputType is the Valibot schema for the expected output.
// Return a parsed object matching the schema.
throw new Error(`Custom model "${modelSlug}" is not implemented.`);
},
};
}
The factory receives:
modelSlug — the full slug (e.g. custom-my-model), so you can route to different backends.
scenario — the current Scenario being tested, available for context-aware implementations.
Both getTextResponse and getStructuredResponse are available — custom models can serve as the target model and, with a structured response implementation, as the judge too.
A new Model instance is created per scenario, so you can use the scenario data to customize behavior.
Then use the slug on the command line like any other model:
yarn kora run custom-my-model
Evaluating a different model
To evaluate a new model, only change the <target-model> argument in the run command. Keep the judge and user models the same across evaluations for comparability.
Risk taxonomy
The benchmark covers 8 risk categories with 25 individual risks:
| Field | Description |
|---|---|
| target | Target model slug |
| judges | Judge model slugs |
| user | User model slug |
| prompts | Prompt variants that were tested |
| sums.al | Total test count |
| sums.as | Safety grades: [failing, adequate, exemplary] |
| sums.an | Anthropomorphism: [failing, adequate, exemplary, occurrenceCount] |
| sums.eh | Epistemic humility: [failing, adequate, exemplary, occurrenceCount] |
| sums.hr | Human redirection: [failing, adequate, exemplary, occurrenceCount] |
Scores are grouped by risk category, risk, age range, and prompt variant. Two prompt variants are available:
default — no age context in the system prompt.
child — the system prompt includes the child's age range.
Use --prompts default,child to test both variants.
Cost and duration
Each pipeline stage makes the following API calls:
Seed generation: 1 call per (risk x age range x motivation) combination = 25 x 3 x 10 = 750 calls, producing 8 seeds each (6,000 seeds total).
Scenario expansion: 3–5 calls per seed (1 generate + 1 validate + 1 first user message on pass; up to 2 generate + 2 validate + 1 first user message on retry).
Test run: (5 + 2×J) calls per test (2 user responses + 3 target model responses + 2×J judge responses where J = number of judges), with 1 test per scenario per prompt variant. With the default single judge, this is 7 calls per test.
All commands run with a concurrency of 10 parallel tasks.
Project structure
.env.example Environment variable template
models.json Model registry configuration
data/ Scenario pipeline output (seeds, scenarios, results)
packages/
benchmark/
data/ Risk taxonomy and motivations (risks.json, motivations.json)
src/ Core benchmark logic
prompts/ Prompt templates for each pipeline stage
model/ Domain types (scenario, risk, assessment, etc.)
__tests__/ Test suites
benchmark.ts Core benchmark interface
generateUserMessage.ts User message generation
kora.ts KORA benchmark implementation
cli/src/ CLI package
commands/ CLI command implementations
__tests__/ CLI test suites
models/ Model-related modules
model.ts Model interface definition
gatewayModel.ts AI SDK gateway model implementation
modelConfig.ts Model registry loader
customModel.ts Custom model hook (edit to add your own)
retry.ts Retry with exponential backoff
cli.ts CLI entry point
Development
yarn tsbuild # Type check
yarn test # Run tests
yarn lint # Lint
yarn pretty # Check formatting