---
title: "Deliver a frontend tool execution result."
url: https://docs.gleap.ai/en/reference/rest-api/deliver-result
method: POST
path: "/frontend-tools/result"
api: "API Reference"
tag: "FrontendTools"
operationId: "DeliverResult"
updatedAt: "2026-11-01T18:40:15.677Z"
language: en
---

# Deliver a frontend tool execution result.

`POST https://api.gleap.io/v3/frontend-tools/result`

Deliver the result of a frontend tool execution from the customer's app. Called by the Gleap SDK. Requires the project API key in the `api-token` header plus a valid widget session (`gleap-id`/`gleap-hash` headers); returns 401 otherwise and 403 if the calling domain is not an allowed widget domain. `result`/`error` payloads above 50,000 characters are rejected with 400; accepted payloads are truncated to 20,000 characters before being handed to the agent. (Gleap.registerAgentTool handler) back to the awaiting agent.

## Request body (`application/json`, required)

- `error` (string)
- `result` (any)
- `toolCallId` (string, required)

## Example request

```bash
curl --request POST \
  --url https://api.gleap.io/v3/frontend-tools/result \
  --header 'Content-Type: application/json' \
  --data '{
  "toolCallId": "<toolCallId>"
}'
```

## Responses

### 200 (`application/json`)

Ok

- `delivered` (boolean, required)

```json
{
  "delivered": true
}
```