Building Tools

A tool is Celigo's first-class reusable building block. It encapsulates logic -- lookups, imports, transforms, branching -- behind a defined input and output contract. Build it once, use it everywhere: from Flows, APIs, AI Agents, MCP Servers, and other Tools.

Tool Concepts

Why tools exist: Without tools, users build the same lookup-transform-import patterns repeatedly across Flows, APIs, and Agents. Tools solve this by providing a governed, composable abstraction: one definition, many consumers, consistent behavior.

When to build a tool:

• You're building an MCP server -- MCP servers expose tools as endpoints; every piece of logic an MCP server offers must be a tool
• The same logic is needed by 2+ consumers (flows, APIs, agents, MCP servers) -- build once, call everywhere
• You want connection flexibility -- callers can pass different connections to the same tool definition
• You're composing smaller pieces -- tools can call other tools for nested orchestration

When NOT to build a tool: