---
title: Overview
description: How AutoFixture resolves Create requests through the kernel — pipeline, builders, and request specifications.
---

Most tests only need [Fixture and Create](/docs/fundamentals/fixture-and-create), [Build DSL](/docs/fundamentals/build-dsl), and [Customizations](/docs/fundamentals/customizations). The articles here explain **how that works inside** `Fixture` — useful when you extend AutoFixture, debug unexpected specimens, or wire custom `ISpecimenBuilder` nodes.

## In this section

1. [Specimen pipeline](/docs/advanced/specimen-pipeline) — behaviors, customizations, engine, and residue collectors
2. [Specimen builders and specifications](/docs/advanced/specimen-builders-and-specifications) — `ISpecimenBuilder`, `IRequestSpecification`, and graph composition

## Related

- [Specimen graphs](/docs/fundamentals/specimen-graphs) — nested **objects** produced by `Create<T>()` (not the kernel graph)
- [Customizations catalog](/docs/fundamentals/customizations-catalog) — reusable `ICustomization` types
- [Idioms](/docs/extensions/idioms) — guard-clause and idiom assertions
- [Seed extensions](/docs/extensions/seed-extensions) — seeded `Create` / `CreateMany` / `Freeze`