Tool Call
A tool call is a structured action Theo invokes during a response — like create_flowchart, send_email, or db_run_sql — that produces a real artifact or side effect, not just text.
In depth
Tool calls are how Theo turns natural language into actual work. Each tool has a typed schema, a permission descriptor, and a server-side execution path. The model proposes the call, the runtime validates it, and the result streams back to the chat as an artifact card or status update.
OpenCharts ships dozens of tools — flowchart, whiteboard, notes, presentation, table, code project, podcast, calendar, image, video, knowledge map, integrations, and more. Skills extend the set with namespaced custom tools.
Examples
- create_flowchart
- send_telegram
- db_run_sql
- create_podcast
Also known as
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How tools workRelated terms
Artifact
An artifact is any concrete deliverable Theo produces — a flowchart, deck, document, table, podcast, movie, code project, calendar, image, or video — surfaced as an interactive card in chat.
Skill
A skill is an installable extension that gives Theo a new behavior — a domain prompt, custom tools, allowed base tools, and an optional trigger (manual, event, schedule, or keyword).
Generative UI
Generative UI is OpenCharts’ pattern of streaming live, interactive components — flowcharts, tables, code previews, calendars, image canvases — directly into the chat as Theo answers.