> Source: https://builder-docs.ema.ai/agent-reference/core/response-validator
> Title: Response Validator Agent

# Response Validator Agent

The Response Validator agent validates generated responses against configurable quality and compliance criteria. It evaluates a response and returns a pass/fail judgment with specific issues identified when validation fails. Use this agent as a quality gate in any workflow where AI-generated content must meet defined standards before reaching the end user.

## Use Cases

-   You need automated quality checks on AI-generated responses before they reach the user.
-   Compliance rules require that responses meet specific criteria (no PII, no unauthorized claims, appropriate tone).
-   You want to gate responses and route failures to human review or a retry loop.
-   You want to validate that action calling results or search-grounded responses meet accuracy and formatting standards before delivery.

## Inputs

Input

Type

Description

`response`

Text

The response to validate.

`query`

Text

(Optional) The original query, for relevance checking.

`search_results`

SearchResults

(Optional) The source material, for grounding checks.

## Outputs

Output

Type

Description

`is_valid`

Boolean

Whether the response passed all validation criteria.

`issues`

Text

Description of any validation failures. Empty if valid.

## Configurations

Parameter

Description

Default

`criteria`

List of validation criteria. Each criterion has a name, description, and severity.

Required

`instructions`

Additional validation instructions.

None

### Defining Validation Criteria

Each criterion is defined in natural language with a name and description. Common validation patterns include:

-   **Grounding** -- "The response must be supported by the provided search results. Do not include claims that are not backed by a source."
-   **Tone and brand compliance** -- "The response must use a professional, empathetic tone. Avoid jargon or overly casual language."
-   **PII protection** -- "The response must not include personal identifiable information such as email addresses, phone numbers, or account numbers."
-   **Relevance** -- "The response must directly address the user's query. Flag responses that go off-topic or provide unrequested information."
-   **Completeness** -- "The response must fully answer the question. If partial information is available, the response should acknowledge what is missing."

### Quality Gating Patterns

The Response Validator is typically used as a quality gate between a response agent and the workflow output. When validation fails, you can:

-   **Route to human review** -- Send invalid responses to a human reviewer via the [Human Collaboration](/legacy-docs/agent-reference/core/human-collaboration) agent.
-   **Abstain from answering** -- Suppress the response entirely using the [Abstain from Answering](/legacy-docs/agent-reference/core/abstain-from-answering) agent and return a safe fallback message.
-   **Branch on severity** -- Use the `is_valid` output as a condition to branch the workflow: valid responses proceed to output, while invalid responses take an alternate path.

## How to Use This Agent

Quality gate with human fallback:

```
chat_trigger -> knowledge_search -> respond_using_search_results -> response_validator
 -> [valid] -> workflow_output
 -> [invalid] -> human_collaboration -> workflow_output
```

Validate action calling results before delivery:

```
chat_trigger -> intelligent_actions -> respond_using_action_calling_results -> response_validator
 -> [valid] -> workflow_output
 -> [invalid] -> abstain_from_answering -> workflow_output
```

## Related Agents

-   [Rule Validation](/legacy-docs/agent-reference/core/rule-validation) -- validates documents or data against rule sets (not specifically responses).
-   [Abstain from Answering](/legacy-docs/agent-reference/core/abstain-from-answering) -- for suppressing responses entirely.
-   [Human Collaboration](/legacy-docs/agent-reference/core/human-collaboration) -- for routing failed validations to human review.
-   [Respond using Search Results](/legacy-docs/agent-reference/core/respond-using-search-results) -- a common upstream agent whose output benefits from validation.
-   [Respond using Action Calling Results](/legacy-docs/agent-reference/core/respond-using-action-calling-results) -- validate action summaries before they reach the user.