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

# mellea.plugins.hooks.component

> Component lifecycle hook payloads.

export const SidebarFix = () => <script dangerouslySetInnerHTML={{
  __html: `
        (function () {
          const INTERVAL_MS = 500;

          const upgradeSidebar = () => {
            const links = document.querySelectorAll('a[href^="#"]');

            links.forEach((link) => {
              if (link.dataset.badged === "true") return;

              const rawText = (link.textContent || "").trim();

              // ========== FUNC ==========
              if (rawText.startsWith("FUNC ")) {
                const label = rawText.replace(/^FUNC\\s+/, "").trim();

                while (link.firstChild) link.removeChild(link.firstChild);

                // 👉 Make the whole link a single flex row & prevent wrapping
                link.style.display = "flex";
                link.style.alignItems = "center";
                link.style.whiteSpace = "nowrap";
                link.style.columnGap = "0.5rem";

                const badge = document.createElement("span");
                badge.style.marginRight = "0.5rem";
                badge.style.display = "inline-flex";
                badge.style.alignItems = "center";
                badge.style.borderRadius = "9999px";
                badge.style.padding = "0rem 0.6rem";
                badge.style.fontSize = "0.5rem";
                badge.style.fontWeight = "700";
                badge.style.letterSpacing = "0.05em";
                badge.style.backgroundColor = "rgba(48, 100, 227, 0.20)";
                badge.style.color = "#1D4ED8";

                badge.textContent = "FUNC";

                link.appendChild(badge);
                link.appendChild(document.createTextNode(label));
                link.dataset.badged = "true";
                return;
              }

              // ========== CLASS ==========
              if (rawText.startsWith("CLASS ")) {
                const label = rawText.replace(/^CLASS\\s+/, "").trim();

                while (link.firstChild) link.removeChild(link.firstChild);

                // 👉 Same flex / nowrap treatment for class links
                link.style.display = "flex";
                link.style.alignItems = "center";
                link.style.whiteSpace = "nowrap";
                link.style.columnGap = "0.5rem";

                const badge = document.createElement("span");
                badge.style.marginRight = "0.5rem";
                badge.style.display = "inline-flex";
                badge.style.alignItems = "center";
                badge.style.borderRadius = "9999px";
                badge.style.padding = "0rem 0.6rem";
                badge.style.fontSize = "0.5rem";
                badge.style.fontWeight = "700";
                badge.style.letterSpacing = "0.05em";
                badge.style.backgroundColor = "rgba(74, 222, 128, 0.20)";
                badge.style.color = "#15803D";

                badge.textContent = "CLASS";

                link.appendChild(badge);
                link.appendChild(document.createTextNode(label));
                link.dataset.badged = "true";
                return;
              }
            });
          };

          upgradeSidebar();
          setInterval(upgradeSidebar, INTERVAL_MS);
        })();
      `
}} />;

<SidebarFix />

Component lifecycle hook payloads.

## Classes

<div className="w-full h-px bg-gray-200 dark:bg-gray-700 my-4" />

### <span className="ml-2 inline-flex items-center rounded-full px-2 py-1 text-[0.7rem] font-bold tracking-wide bg-[#4ADE8033]/20 text-[#15803D]">CLASS</span> `ComponentPreExecutePayload` <sup><a href="https://github.com/generative-computing/mellea/blob/v0.6.0/mellea/plugins/hooks/component.py#L10" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

Payload for `component_pre_execute` — before component execution via `aact()`.

**Attributes:**

* `component_type`: Class name of the component being executed.
* `action`: The [`Component`](../../core/base#class-component) or [`CBlock`](../../core/base#class-cblock) about to be executed.
* `context_view`: Optional snapshot of the context as a list.
* `requirements`: List of [`Requirement`](../../core/requirement#class-requirement) instances for validation (writable).
* `model_options`: Dict of model options passed to the backend (writable).
* `format`: Optional `BaseModel` subclass for structured output / constrained decoding (writable).
* `strategy`: Optional [`SamplingStrategy`](../../core/sampling#class-samplingstrategy) instance controlling retry logic (writable).
* `tool_calls_enabled`: Whether tool calling is enabled for this execution (writable).

<div className="w-full h-px bg-gray-200 dark:bg-gray-700 my-4" />

### <span className="ml-2 inline-flex items-center rounded-full px-2 py-1 text-[0.7rem] font-bold tracking-wide bg-[#4ADE8033]/20 text-[#15803D]">CLASS</span> `ComponentPostSuccessPayload` <sup><a href="https://github.com/generative-computing/mellea/blob/v0.6.0/mellea/plugins/hooks/component.py#L34" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

Payload for `component_post_success` — after successful component execution.

**Attributes:**

* `component_type`: Class name of the executed component.
* `action`: The [`Component`](../../core/base#class-component) or [`CBlock`](../../core/base#class-cblock) that was executed.
* `result`: The [`ModelOutputThunk`](../../core/base#class-modeloutputthunk) containing the generation result.
* `context_before`: The [`Context`](../../core/base#class-context) before execution.
* `context_after`: The [`Context`](../../core/base#class-context) after execution (with action + result appended).
* `generate_log`: The [`GenerateLog`](../../core/base#class-generatelog) from the final generation pass.
* `sampling_results`: Optional list of [`ModelOutputThunk`](../../core/base#class-modeloutputthunk) from all sampling attempts.
* `latency_ms`: Wall-clock time for the full execution in milliseconds.

<div className="w-full h-px bg-gray-200 dark:bg-gray-700 my-4" />

### <span className="ml-2 inline-flex items-center rounded-full px-2 py-1 text-[0.7rem] font-bold tracking-wide bg-[#4ADE8033]/20 text-[#15803D]">CLASS</span> `ComponentPostErrorPayload` <sup><a href="https://github.com/generative-computing/mellea/blob/v0.6.0/mellea/plugins/hooks/component.py#L61" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

Payload for `component_post_error` — after component execution fails.

**Attributes:**

* `component_type`: Class name of the component that failed.
* `action`: The [`Component`](../../core/base#class-component) or [`CBlock`](../../core/base#class-cblock) that was being executed.
* `error`: The `Exception` that was raised.
* `error_type`: Class name of the exception (e.g. `"ValueError"`).
* `stack_trace`: Formatted traceback string.
* `context`: The [`Context`](../../core/base#class-context) at the time of the error.
* `model_options`: Dict of model options that were in effect.

<div className="w-full h-px bg-gray-200 dark:bg-gray-700 my-4" />