Open Prompt Archive (OPA)

A portable, self-contained archive format for packaging AI agent prompts together with their session history, data assets, and execution metadata.

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Ready to run OPA files? Download OPA Runner — a cross-platform desktop app for opening and executing .opa archives in sandboxed containers. Available for Windows, macOS, and Linux.

Why OPA?

Running AI analysis on the server is expensive. OPA lets you package data with analysis instructions and distribute it to users who run it with their own AI — shifting costs, preserving privacy, and giving users the flexibility to add their own context.

How OPA bridges server intelligence and user context

See Use Cases

What is OPA?

The Open Prompt Archive is a ZIP-based, portable archive format (.opa) that packages everything needed to execute an AI agent task:

A prompt — the primary instruction for the agent
Session history — prior conversation context for continuity
Data assets — files the prompt references and the agent can access
Metadata — manifest describing the archive and execution parameters

OPA archives are distributable units that any compatible client can extract and execute using any AI agent in a sandboxed container environment.

OPA Architecture Overview

Get Started

Run OPA Files

Download OPA Runner to open and execute .opa files on your desktop.

Download OPA Runner

Create OPA Files

Use an official library to generate OPA archives in your preferred language.

Browse Libraries

Read the Spec

Dive into the full specification to understand the format and build your own tools.

View Specification

Explore Use Cases

See real-world examples of OPA in action, from inventory analysis to compliance audits.

View Use Cases

Language Support

Official libraries are available for five languages:

Language	Package	Install
Java	opa-java	Maven: `ca.weblite:opa-core`
JavaScript	opa-js	`npm install opa-js`
Python	opa-python	`pip install opa-archive`
PHP	opa-php	`composer require opa/opa-php`
Ruby	opa-ruby	`gem install opa-ruby`

See all libraries

Key Design Principles

Design Principles

Principle	Description
Agent-agnostic	No assumption about a specific AI provider, model, or API
Container-friendly	Straightforwardly extractable into a container filesystem
Human-readable	Manifest and prompt files use plain text formats (Markdown, JSON)
Toolchain compatible	Openable by standard ZIP tools (`jar`, `unzip`, `7-Zip`)
Extensible	New capability fields can be added without breaking older clients
Minimal	A valid archive requires only a manifest and a prompt file

Quick Example

A typical OPA archive contains:

sales-summary.opa
│
├── META-INF/
│   └── MANIFEST.MF
│
├── prompt.md
│
├── session/
│   ├── history.json
│   └── attachments/
│       └── previous-draft.md
│
└── data/
    ├── INDEX.json
    ├── q1/
    │   ├── north-region.csv
    │   └── south-region.csv
    └── reference/
        └── targets-2026.xlsx

Status

This specification is currently in Draft status (v0.1.0). Version 1.0 will be published following at least two independent interoperable implementations.