Experts
An Expert is a saved program. Extella supports Experts written in fython / Python, CSPL Experts and composite Experts built from several parts.
Section 02 / Software
iCon containers
Store programs for repeated use.
iCon is an interpreted container: a capability packaged so it can be read, called, moved and changed in parts.
Why it helps
A saved program can be called again. The model does not need to recreate the same action every time.
What it contains
CSPL
The program and its handler are separate. An action description can be changed independently of its execution, and handler changes can be checked before replacement.
Handlers
A handler determines how a program runs. The map describes handlers for tasks ranging from data and web pages to a robot simulation.
Where code runs
The targets array names the devices where the Expert should run. Use a device identifier in this array. The tool and its execution device are separate building blocks.
What was measured
Extella measurements, September and October 2026. Each number holds under the conditions given.
- A rule changes for every program at once.
Live site extella.dev/live/, 16.10.2026: a new site law was registered in 8.8 seconds. The page changed for 24 kinds of visitors out of 72, and not a single line of the saved programs changed. A site law here is a new version of the handler.
- A new handler version is not registered if it breaks a saved program.
Before registration it runs every saved program. A law that would have broken 2 programs out of 3 was not registered. The check catches only what is written in the site rules, and a person writes those rules.
- A program in a small language is checked in full.
Checking the site program against all 72 kinds of visitors took 0.3 milliseconds, and against a million kinds, 4 seconds. Measured on a MacBook.
- The check was attacked and made stronger.
On 16.10.2026 about 40 attacks were sent to the four open languages of the extella.dev site. Three kinds of holes turned up: a banned word with a look-alike letter from another alphabet or an invisible character, a button with no length limit, and a crash on the character «²». Each hole was closed by editing one handler file; the saved programs did not change. These attacks now run before every handler replacement.
- An expert is a large operation, not a small function.
The same task split into 27 experts took 630 seconds, and built as one expert, 90 seconds, with the same result. Every expert call goes through the platform and takes seconds.
Articles and demos
ArticleCSPL: a program is stored separately from the way it is executedTechnical description: the expert record, the two calls, declaring a language, what was verified, limits and how to reproduce.What it shows: New tools for an agent without changing the server: a program is stored with the name of its language and runs under a handler on any prepared device.ArticleHow Extella is builtThe program and its execution are configured separately; the handler can be changed without touching the program.What it shows: The program and the way it runs are separate: the handler changes, the program text stays the same.DocumentationA program is stored under a nameSave the code once and call the same program from an agent, an application or your own script.DemoTen CSPL gamesIn each game you change a short program in a narrow language; its handler on a Linux server answers or names the line it refuses. Handlers call other handlers and themselves.What it shows: The rules live in the handler, not in the prompt: a refusal names the line it refuses, one law change reaches every saved program of the language, and a run makes no model calls.DemoRush hourWrite the rules for a city's traffic lights in a tiny language; the handler checks them before the city runs.What it shows: One language, one result everywhere: the traffic-light rules run the same in the browser and on the server, which replays them and confirms the score, so the mayors' table cannot be faked.
Related articles and examples.
Where it is used
AppsBuild a request-tracking appExplore apps ReportsGenerate a report from a CSV fileTry the report demo RobotsTest a delivery routeTry the simulation SensorsRespond to a sensor readingHow device execution works WebsitesAdapt a page to its visitorsOpen the coffee shop site AI assistantsFind answers in team materialsHow agents use tools