> ## Documentation Index
> Fetch the complete documentation index at: https://isol8.notdhruv.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Execute

> Run code and return buffered execution results.

Runs one execution request and returns complete `stdout`/`stderr` and metadata.

## Body

<ParamField body="request" type="ExecutionRequest" required>
  Execution payload including `code` and `runtime` plus optional per-request fields.
</ParamField>

<ParamField body="options" type="Isol8Options">
  Optional engine-level overrides merged over server defaults.
</ParamField>

<ParamField body="sessionId" type="string">
  Optional persistent session key. If provided, server creates/reuses a persistent session.
</ParamField>

## Success response

<ResponseField name="stdout" type="string">
  Captured standard output.
</ResponseField>

<ResponseField name="stderr" type="string">
  Captured standard error.
</ResponseField>

<ResponseField name="exitCode" type="number">
  Process exit code.
</ResponseField>

<ResponseField name="durationMs" type="number">
  Execution duration in milliseconds.
</ResponseField>

<ResponseField name="truncated" type="boolean">
  Whether output was truncated by max output limits.
</ResponseField>

<ResponseField name="executionId" type="string">
  Unique execution identifier.
</ResponseField>

<ResponseField name="runtime" type="string">
  Runtime used for this execution.
</ResponseField>

<ResponseField name="timestamp" type="string">
  ISO timestamp for execution completion.
</ResponseField>

<RequestExample>
  ```bash theme={null}
  curl -X POST http://localhost:3000/execute \
    -H "Authorization: Bearer $ISOL8_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{
      "request": {
        "runtime": "python",
        "code": "print(2 ** 10)"
      },
      "options": {
        "network": "none",
        "timeoutMs": 30000
      }
    }'
  ```
</RequestExample>

<ResponseExample>
  ```json theme={null}
  {
    "stdout": "1024\n",
    "stderr": "",
    "exitCode": 0,
    "durationMs": 82,
    "truncated": false,
    "executionId": "550e8400-e29b-41d4-a716-446655440000",
    "runtime": "python",
    "timestamp": "2026-02-19T12:00:00.000Z"
  }
  ```
</ResponseExample>