Chronos

An AI agent that collaborates with historians to extract structured datasets from primary sources, adapt to heterogeneous documents, and accumulate domain knowledge across sessions. Chronos combines a document analysis agent with a VS Code extension to analyze scanned page images, extract structured data, and build knowledge about archival sources.

Prerequisites

• VS Code (v1.110+)
• Node.js (v18+) — required by the underlying pi agent the extension installs on first run
• An API key for an AI provider with a vision-capable model (Anthropic, Google, OpenAI, …). You connect it from inside the panel — see Start the agent.

Installation

Install the Chronos — The AI Historian extension from inside VS Code:

1. Open the Extensions view (Ctrl+Shift+X, or Cmd+Shift+X on macOS).
2. Search for Chronos — The AI Historian.
3. Click Install.

Several extensions match "Chronos" — pick Chronos — The AI Historian (by AI-Historian), then click Install.

That's it. The first time you run a Chronos command, the extension checks for pi (the AI agent framework Chronos runs on) and the Chronos pi-package, and offers to install both in a terminal — no manual npm install -g or pi install step required.

Manual install (advanced / offline)

If you'd rather install everything by hand:

# 1. Install the pi agent globally
npm install -g @earendil-works/pi-coding-agent

# 2. Register the Chronos pi-package
pi install https://github.com/ai-historian/chronos

# 3. Install the VS Code extension from a downloaded .vsix
code --install-extension chronos-ai-historian-0.2.0.vsix

The .vsix is published on GitHub Releases.

Getting started

Every Chronos action lives in the Command Palette — press Ctrl+Shift+P and type chronos.

The three steps below all start here: Start Agent Session, Connect AI Provider, and Import Sources.

1. Initialize a workspace

Open VS Code in an empty folder. Press Ctrl+Shift+P and run Chronos: Init Workspace. This creates the workspace structure. (You connect an AI provider in step 3 — no key is needed yet.)

Init Workspace scaffolds sources/, data/, memory/, skills/, and sessions/ into the folder.

2. Import sources

Press Ctrl+Shift+P and run Chronos: Import Sources. Choose whether to select individual files or a whole folder of source material — PDFs, images (PNG, JPG, TIFF, BMP), or text files. Each file is treated as a source. PDFs are automatically converted to page images. You can import additional sources at any time by running the command again.

Pick individual files (PDF / image / text) or a whole folder.

Converting a large PDF can take a few minutes. Imports are crash-safe: a source only appears once it has finished converting, and if VS Code is closed or crashes mid-conversion, Chronos detects the interrupted import on the next launch (and when you next run Import Sources) and offers to Resume it (it picks up where it left off) or Discard the partial data.

Note: PDFs are streamed page-by-page during conversion, so there are no extra tools to install. Files over 2 GiB are automatically split into smaller parts first (this briefly uses a few GB of RAM). If a very large PDF still gives you trouble, please open an issue so we can look into it.

3. Start the agent

Press Ctrl+Shift+P and run Chronos: Start Agent Session. The Chronos panel opens — a page viewer on the left and a chat on the right.

From the panel header you select a Source, Log in, or start a New session.

On first startup no AI models are available until you connect a provider. Click Log in in the panel header (or run Chronos: Connect AI Provider) and choose how to sign in:

• Anthropic — Claude Pro/Max (subscription): signs in with your Claude subscription via OAuth in the browser — no API key needed. The credential is stored in pi's ~/.pi/agent/auth.json.
• API key (any provider): paste a key; Chronos saves it to the workspace .chronos/.env.

Sign in with a Claude subscription, or paste an API key for any supported provider.

Either way Chronos reconnects automatically. You can switch or add providers the same way at any time.

Pick a source from the header dropdown (or type /select-source) and begin working.

Once a source is selected, its pages render in the viewer and the agent is ready.

Configuration

AI provider & models

Connect a provider with the Log in button (above); it stores the key in .chronos/.env. You can also edit that file directly — pi reads the standard per-provider variables:

ANTHROPIC_API_KEY=...      # Claude
GEMINI_API_KEY=...         # Google Gemini
OPENAI_API_KEY=...         # OpenAI
# OPENROUTER_API_KEY, XAI_API_KEY, MISTRAL_API_KEY, GROQ_API_KEY, DEEPSEEK_API_KEY, …

The page-analysis tools (task / task_batch) default to the model selected in the header, but accept any vision-capable model pi has auth for via a model: "provider/model-id" argument. Chronos is provider-agnostic — choose what fits your budget and accuracy needs. As a starting point, a fast/cheap vision model (e.g. google/gemini-3-flash-preview) works well for routine pages, and a stronger model (e.g. google/gemini-3.1-pro-preview or anthropic/claude-opus-4-8) helps on dense or damaged pages.

pi options

pi supports many options natively. Common ones:

# Use a specific model
pi --model anthropic/claude-opus-4-8

# Continue previous session
pi -c

# Resume a specific session
pi -r

Run pi --help for the full list.

Documentation

See DOCS.md for technical details on workspace structure, tools, skills, memory, and the VS Code extension.

Citation

@article{hufe2026towards,
  title={Towards the AI Historian: Agentic Information Extraction from Primary Sources},
  author={Hufe, Lorenz and Griesshaber, Niclas and Greif, Gavin and Eck, Sebastian Oliver and Torr, Philip},
  journal={arXiv preprint arXiv:2604.03553},
  year={2026}
}

License

Chronos is licensed under the PolyForm Noncommercial License 1.0.0. You may use, modify, and share it freely for any noncommercial purpose (including research, education, and use by nonprofit and government organizations). Commercial use requires a separate license — please get in touch.

See LICENSE for the full terms.