Panopticon (core)

I wrote this library to encapsulate some required functionality for a series of tools I want to build. This project started with a icky and arguably 'vibe-coded' attempt to build a TUI tool for chaining KQL queries run against Sentinel workspaces (See kql-panopticon). This worked fine at first but fell apart when I started trying to build 'packs', the workflows of 'steps' (now commands) and input parameters. This library provides a way to execute commands in a much safer / observable way and a way to add in new commands. I plan to write commands that implement these traits in other crates and then use the core + extended crates to write more delibrate tooling.

What does it do?

Panopticon-core is a Rust library for building declarative data pipelines. You define commands, wire them together in namespaces, and execute them through a state-machine pipeline (Draft → Ready → Completed). The type system enforces valid transitions at compile time — you can't execute a pipeline that hasn't been compiled, and you can't add commands to one that's already running.

Commands implement three traits: Descriptor (schema), FromAttributes (construction from key-value pairs), and Executable (async execution). Each command declares its expected inputs and outputs through a spec system that validates attribute names, types, and reference kinds. A CommandSpecBuilder provides compile-time guarantees — for example, derived result names (where a result's name comes from an attribute value) can only reference fields proven to be literals via an opaque LiteralFieldRef type.

Namespaces group commands and control execution mode:

• Once — commands run sequentially, one time.
• Iterative — commands run N times over an array, object keys, or table rows, with item and index injected into context each iteration.
• Static — no execution, just key-value configuration loaded at pipeline start.

During execution, commands read and write to two stores: a scalar store (backed by Tera contexts, so values are available in template expressions) and a tabular store (Polars DataFrames). Commands can reference other commands' outputs via StorePath dot-notation (namespace.command.field), and the pipeline resolves dependencies to determine execution order.

The library ships with five built-in commands:

• file — load CSV, JSON, or Parquet files into the tabular store.
• sql — run SQL queries against tabular data using Polars' SQL context.
• aggregate — compute sum, mean, min, max, count, etc. over tabular columns.
• condition — evaluate conditional branches using Tera expressions.
• template — render Tera templates to files or capture output as a result.

After execution, a ResultStore collects all outputs, writes tabular data to disk in the requested format, and separates metadata (status, duration) from data results.

Examples

examples/prelude/ covers pipeline usage:

• aggregate_and_export.rs — load CSV, run aggregations, export results.
• when_conditional.rs — conditionally skip commands using the when attribute.
• pipeline_reuse.rs — re-enter Draft from Completed to add commands and re-execute.
• iterate_object_keys.rs — iterate over object keys in a namespace.
• template_inheritance.rs — render Tera templates with inheritance.
• multi_format_load.rs — load CSV, JSON, and Parquet in one pipeline.

examples/extend/ covers implementing new commands:

• custom_command.rs — implement a custom command end-to-end (Descriptor, FromAttributes, Executable) and run it in a pipeline.
• command_spec_safety.rs — demonstrates the CommandSpecBuilder safety mechanisms: LiteralFieldRef compile-time proofs, NamePolicy violations, and builder validation errors.

What's next?

• Additional safety checks at compile and lazylock time.
• Narrow the extend API surface, starting with AttributeSpec used in CommandSpecBuilder, need to write a builder or change the attribute function.
• Extend the spec types to support more verbose ResultStore schema (Maybe consider a ser/de approach to result capture using the specs as a schema?)
• Add some serde support for the specs.
• Write actual documentation, lol
• Create a dedicated panopticon-kql crate that uses the panopticon-core traits. Will likely write two commands, one for Defender XDR (via the Graph API) and one for Sentinel workspaces (basically already done in the previous tool attempts).
• Explore forensic parser integrations, for example a command type that can expose a EVTX file as a TabularValue. Lots of very fun applications for something like this.
• Finish the TUI attempt started in kql-panopticon but using this library and pipeline approach. I think the way I've written the API lends itself well to the REPL approach started but I wasn't engaged enough in how the Ratatui library was being used and alot of functionality got conflated in with the UI (so it's not a quick fix, better to focus on deliberate CLIs for specific tasks).

Changelog

1. v0.1.0 - Initial implementation
2. v0.2.0 - Added in the extensions and services modules. Services are specific bits of functionality I want to allow consumers of this library to extend, that includes PipelineIO and EventHooks right now. Extensions is a new type that lives inside ExecutionContext, runtime within Pipeline::<Ready> during execution. The inner map can contain an Arc of a specific type. The idea is certain commands will want to generate and or consume a shared type, for example a HTTP client (the use case that drove the design of these type). Added tokio_utils CancellationToken as a test of extensions, this is a built in example but the M365 crate client will be a true extension.