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When the built-in and pre-installed tools do not cover something specific to your team, you can create custom tools of your own. A custom tool is a small TypeScript or Python function with a defined input and output schema. It is stored in your account and runs inside your sandbox, so it can call internal APIs, wrap proprietary tooling, or encode a repeatable step in your methodology.

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When to create a custom tool

You have an internal API or service. If a step in your workflow means calling an internal endpoint, a ticketing system, or a proprietary data source, a custom tool gives the agent a typed, reliable way to do it instead of hand-written curl commands. You repeat the same multi-step operation. Recurring logic like normalizing scan output, enriching a finding, or querying an asset inventory is more reliable as a single tool than as instructions the agent re-derives each time. You want to wrap proprietary tooling. Custom tools let you expose your own scanners or scripts to the agent with a clear contract, so it knows exactly what inputs to pass and what to expect back.

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Anatomy of a custom tool

Every custom tool Neo builds has the same structure:
  • Source code: a TypeScript or Python function that contains the tool’s logic and runs inside your sandbox.
  • Input schema: the typed parameters the agent must provide when it calls the tool.
  • Output schema: the shape of the result the tool returns, so the agent can reason about it.
  • When to use: a description of the situations this tool is for, so the agent knows when to reach for it.
  • Timeout: how long the tool is allowed to run before it is stopped.
Custom tools are grouped into toolkits, which carry the shared setup their tools depend on:
  • Language: whether the toolkit’s tools are written in TypeScript or Python.
  • Dependencies: packages the tools need, installed when the toolkit is set up.
  • Setup code: initialization that runs before the tools, such as configuring a client.
  • Environment variables: configuration and credentials made available to the tools at runtime.
  • Metadata: tags and descriptions for organizing and discovering toolkits.

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How to create a custom tool

You create and manage custom tools through Neo itself by describing what you want: the operation the tool should perform, its inputs, and what it should return. Neo writes the function, defines the input and output schema, registers it inside a toolkit, and tests it to confirm it runs. You can be as specific or as high-level as you like, and Neo fills in the gaps based on your description. For example:
The result is saved as a reusable tool in your account, ready for your agents to use.

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Sharing custom toolkits

Named toolkits can be shared privately with your Neo team. The owner chooses whether each teammate supplies personal or project credentials, or whether the toolkit uses saved credentials the owner explicitly binds for team use. See Team-shared custom toolkits for the Neo and API workflows, credential modes, access rules, and revocation behavior.

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How tools are loaded

Once created, a custom tool can reach your agents in four ways:
  • On-demand: the agent discovers and calls the tool only when a task needs it.
  • Pinned: the tool loads automatically on every task.
  • Attached: the tool is scoped to a specific custom agent, so only that agent sees it.
  • Team-shared: an active teammate discovers a named toolkit shared with their team and can attach it to their own custom agents.
Pinning and attaching let you keep a large library of tools without crowding every agent with all of them at once. Combined with custom agents, custom tools let you adapt Neo to workflows the built-in capabilities do not already cover.