# Quick Example

> Build middleware pipelines in Python with export to JSON/YAML.

- Skill: `tools-only/quick-example-2` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add tools-only/quick-example-2`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tools-only/quick-example-2/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tools-only (https://skillmd.com/u/tools-only)
- Updated: 2026-09-29
- Page: https://skillmd.com/skills/tools-only/quick-example-2

---

# PipelineSpec

Build middleware pipelines in Python with export to JSON/YAML.

`PipelineSpec` provides a fluent API for constructing middleware pipelines that
can be compiled into middleware instances or exported as configuration files.
This is useful for configuration-driven deployments where pipeline definitions
need to be portable.

## Quick Example

```python
from pydantic_ai_middleware import PipelineSpec
from pydantic_ai_middleware.builder import MiddlewarePipelineCompiler

# Build a pipeline spec with fluent API
spec = (
    PipelineSpec()
    .add_type("logging", {"level": "DEBUG"})
    .add_type("rate_limit", {"max_requests": 100})
    .add_when(
        predicate="is_admin",
        then=[{"type": "admin_audit"}],
        else_=[{"type": "user_audit"}],
    )
)

# Export to YAML file
spec.save("middleware-pipeline.yaml")

# Or compile directly to middleware instances
compiler = MiddlewarePipelineCompiler(registry)
middleware_list = spec.compile(compiler)
```

## Supported Node Types

- **type**: A single middleware by registered name
- **chain**: Sequential execution of multiple nodes
- **parallel**: Concurrent execution with result aggregation
- **when**: Conditional branching based on predicates

## API Reference

::: pydantic_ai_middleware.pipeline_spec.PipelineSpec
    options:
      show_source: true
      members:
        - nodes
        - add
        - add_type
        - add_chain
        - add_parallel
        - add_when
        - to_config
        - dump
        - save
        - compile