Testing Tools

The Run panel

Every tool has a built-in Run panel that lets you execute the tool with custom input and inspect the result in real time. Use it to:

Verify tool logic before connecting an AI client
Debug parameter handling
Inspect the exact JSON structure returned to the AI
Test edge cases with specific inputs

Running a tool

Open the Run tab

In the tool editor, click the Run tab (or the play button in the toolbar).

Fill in parameters

The Run panel renders a form field for each parameter you’ve defined. Required parameters are marked.Enter real values — the code runs with exactly what you provide.

Click Run tool

Click the Run tool button. The tool executes in the sandbox with your inputs.

Inspect the result

The response section shows:

Return value — the JSON the AI would receive
Console output — any console.log() / console.error() calls your code made
Execution time — how long the tool took to run
Error — if the tool threw an exception, the full stack trace

Reading console output

console.log(), console.info(), console.warn(), console.error(), and console.debug() all appear in the Run panel’s Logs section during a test run. Use them liberally while developing:

console.log("Fetching data for user:", params.userId);

const rows = await db.select("orders", { user_id: params.userId });

console.log("Found", rows.length, "orders");

if (rows.length === 0) {
  console.warn("No orders found — returning empty result");
  return { orders: [] };
}

return { orders: rows };

Debugging failures

When a tool throws an error, the Run panel shows:

The error message
The full stack trace
The log output that ran before the failure

Common failure patterns:

Symptom	Likely cause
`env.MY_KEY is undefined`	Secret not added to this server, or key name typo
`res.status()` is `401` / `403`	Wrong or expired credentials in secret
`JSON.parse()` throws	Upstream API returned non-JSON (check `res.body()` in a log)
`db.select()` throws	Wrong DB host/port/credentials, or table doesn’t exist
Execution timeout	Tool taking > 10s — inspect what step is slow with `console.time()`

Testing vs production

Runs from the Run panel are real executions — they consume API credits, write to databases, and send real requests to external services. Keep this in mind when testing tools that perform write operations or send notifications.

Test runs appear in Traffic Logs with the source dashboard-run so you can distinguish them from AI-initiated calls.

Testing with secrets

Secrets (env.*) are available during Run panel executions — no special setup needed. The same encrypted values your production code uses are injected into test runs.

Getting Started

MCP Servers

Tools

Observability

Connect AI Clients

The Run panel

Running a tool

Reading console output

Debugging failures

Testing vs production

Testing with secrets

​The Run panel

​Running a tool

​Reading console output

​Debugging failures

​Testing vs production

​Testing with secrets

The Run panel

Running a tool

Reading console output

Debugging failures

Testing vs production

Testing with secrets