> ## Documentation Index
> Fetch the complete documentation index at: https://docs.primeintellect.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

verifiers is a framework for defining tasks, running agents and harnesses, scoring them on set tasks, and using those for evaluations and reinforcement learning.

The following concepts are important when creating or running tasksets, be it for evals or training:

## Environment Hub

The [Environment Hub](https://app.primeintellect.ai/dashboard/environments?ex_sort=most_stars) is Prime Intellect's collection of user-created tasksets which are installable and ready to use with verifiers.

## Taskset

A taskset is the collection and loader for the work to evaluate or train on. Each task combines a serializable `TaskData` row (prompt, files, references, resource requirements) with its task class's behavior (lifecycle hooks, tools, metrics, and rewards). The taskset's `load()` method constructs those objects and declares their task/config types through `Taskset[TaskT, ConfigT]`.

## Harness

A harness is the program the model is run in, e.g. Claude Code, Codex or mini-swe-agent.

## Agent

An Agent is the combination of harness × model × runtime policy which produces a `Trace`.

## Environment

An environment has one or multiple agents and defines the control flow among them.

## Toolset

A set of tools defined by the taskset that are installed as MCP servers into the harnesses that support them.

## Trace

A trace records the message graph, rewards, metrics, errors, and one per-call record (`ModelCall`) per provider exchange (its model, sampling, finish reason, usage, timing, and any error), etc. When using verifiers for training with [prime-rl](https://github.com/PrimeIntellect-ai/prime-rl), it stores additional information such as tokens and logprobs, built incrementally using [renderers](https://github.com/PrimeIntellect-ai/renderers).

## Documentation

* [Getting started](/verifiers/v1/getting_started) - How to install verifiers and the needed skills.
* [Architecture](/verifiers/v1/architecture) — How verifiers works behind-the-scenes
* [Tasksets](/verifiers/v1/tasksets) — How to create tasksets
  * [Harbor Tasksets](/verifiers/v1/harbor) — How to create Harbor-based tasksets
* [Evaluation](/verifiers/v1/evaluation) — How to evaluate tasksets
* [Harnesses](/verifiers/v1/harnesses) — How to build custom harnesses
* [Agent](/verifiers/v1/agent) — How to run standalone agents
* [Env](/verifiers/v1/env) — How to build multi-agent environments

For the documentation for legacy environments, go to [the v0 documentation](/verifiers/v0/overview).