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Prompt

Array Validation-Aware Prompt Template with Error Objects

A practical prompt playbook for AI platform engineers building self-validating generation pipelines that produce arrays alongside per-record error objects, validation status flags, and fix suggestions.
Developer doing prompt engineering on laptop, prompt variations visible on screen, casual coding session.
PROMPT PLAYBOOK

When to Use This Prompt

Define the job-to-be-done, ideal user, required context, and when not to use this prompt for array generation with per-record error objects.

This prompt is designed for AI platform engineers and backend developers building self-validating generation pipelines that must produce arrays of homogeneous records. The core job-to-be-done is generating a bulk record set where every record is accompanied by a validation status, a structured error object for records that fail schema checks, and actionable fix suggestions. This is not a simple list generation prompt; it is a production-grade template for systems that must handle partial success gracefully, allowing a downstream application to ingest valid records immediately while routing invalid records to a repair queue or human review step.

Use this prompt when your pipeline must survive schema violations without failing the entire batch. Ideal scenarios include bulk data ingestion from user uploads, ETL processes where source data quality is unpredictable, and API endpoints that must return a mix of valid and invalid records with clear error provenance. Required context includes a strict target schema (preferably a JSON Schema), a set of validation rules, and a definition of what constitutes a repairable versus non-repairable error. The model is expected to self-evaluate its own output against the provided schema and produce an errors array for each record, containing field, message, severity, and fix_suggestion keys.

Do not use this prompt when you need a simple, flat array of records with no error handling, or when downstream systems cannot process a mixed response payload. If your application layer already has robust validation and repair logic, embedding this logic in the prompt adds token overhead and latency without benefit. Similarly, avoid this prompt for real-time, low-latency streaming scenarios where the self-validation step introduces unacceptable delay. For high-risk domains such as finance or healthcare, the generated error objects and fix suggestions must be treated as advisory only; a human reviewer or a deterministic post-processing validator must confirm every repair before data is committed to a system of record.

PRACTICAL GUARDRAILS

Use Case Fit

Where this prompt works and where it does not. Use these cards to quickly assess whether the Array Validation-Aware Prompt Template is the right tool for your pipeline.

01

Good Fit: Self-Healing Ingestion Pipelines

Use when: You are building a bulk data pipeline that must not fail on a single bad record. This prompt is designed to produce a valid array alongside a per-record error object, allowing you to ingest clean records immediately while flagging failures for repair. Guardrail: Always check the is_valid flag per record before inserting into your target system; never assume the entire array is clean.

02

Bad Fit: Real-Time, Single-Record APIs

Avoid when: Your API contract expects a single, perfectly formed object in a synchronous request-response cycle. The overhead of wrapping a single record in an array with error objects adds unnecessary latency and payload complexity. Guardrail: Use a strict single-object schema prompt for synchronous APIs and reserve this template for batch or asynchronous jobs.

03

Required Inputs: Strict Schema & Validation Rules

Risk: Without a concrete JSON Schema and explicit validation rules, the model will invent its own validity criteria, leading to inconsistent error objects. Guardrail: You must provide a [JSON_SCHEMA] and a set of [VALIDATION_RULES] as input. The prompt's effectiveness is directly proportional to the precision of these inputs.

04

Operational Risk: Silent Partial Failures

Risk: A downstream consumer might ignore the errors array and process only the records array, silently dropping failed records without alerting an operator. Guardrail: Implement a mandatory post-processing check that logs a warning or halts the pipeline if summary.failed_count > 0, ensuring partial success is always surfaced.

05

Good Fit: Retry Targeting

Use when: You want to minimize the cost and latency of retries. The fix_suggestion field in each error object allows you to construct a targeted repair prompt for only the failed records, rather than re-processing the entire batch. Guardrail: Validate that the fix_suggestion itself does not introduce new schema violations before applying it.

06

Bad Fit: Unbounded Collection Sizes

Avoid when: You need to process an input that could yield an extremely large or unpredictable number of records. The model's context window limits the total output size, which can lead to truncated arrays and lost error objects. Guardrail: Chunk the input into smaller batches with a known maximum record count per request to guarantee a complete output.

PROMPT PLAYBOOK

Copy-Ready Prompt Template

A reusable prompt that generates arrays alongside per-record error objects, validation status flags, and fix suggestions for records that fail schema checks.

This template is designed for AI platform engineers building self-validating generation pipelines where partial success is expected. Instead of failing the entire batch when some records don't conform, the prompt instructs the model to produce a structured envelope containing both valid records and detailed error objects for invalid ones. This enables retry targeting, downstream quarantine logic, and audit trails without losing the records that did pass validation.

text
You are a structured data generator operating in a validation-aware pipeline. Your task is to produce an array of records from the provided [INPUT] that conform to the target schema defined in [OUTPUT_SCHEMA]. Not all input items may be valid or complete. For each record, you must assess whether it passes schema validation and include that assessment in your output.

## Output Envelope
Return a single JSON object with the following structure:
{
  "records": [],
  "errors": [],
  "summary": {
    "total_processed": 0,
    "total_valid": 0,
    "total_invalid": 0
  }
}

## Records Array
Each element in `records` must conform exactly to [OUTPUT_SCHEMA]. Only include records that pass validation. Do not include partial or repaired records here unless [REPAIR_MODE] is set to `true`.

## Errors Array
For each input item that fails validation, include an error object in the `errors` array with:
- `index`: the zero-based position of the failed item in the input
- `input_snippet`: a truncated representation of the failed input for traceability
- `validation_errors`: an array of specific field-level failures, each containing:
  - `field`: the field path that failed (use dot notation for nested fields, e.g., "address.zip")
  - `rule`: the validation rule that was violated (e.g., "required", "type_mismatch", "enum_violation", "pattern_mismatch")
  - `expected`: what the schema requires
  - `received`: what the input provided (or "null" if missing)
- `fix_suggestion`: a human-readable suggestion for how to correct the record, or "cannot_suggest" if the input is too ambiguous
- `retry_priority`: one of [HIGH, MEDIUM, LOW] indicating whether this record is likely fixable with a targeted retry

## Validation Rules
Apply the following checks in order, stopping at the first failure for each field:
1. Required field presence: all fields listed in [REQUIRED_FIELDS] must exist and not be null
2. Type conformance: each field must match the type specified in [OUTPUT_SCHEMA] with no coercion
3. Enum constraints: fields restricted to [ENUM_VALUES] must contain only allowed values
4. Pattern constraints: fields with [PATTERN_RULES] must match the specified regex
5. Custom constraints: apply any additional rules in [CUSTOM_VALIDATION_RULES]

## Constraints
- Do not invent data to fill missing required fields unless [DEFAULT_MAP] is provided and the field is listed there
- Do not coerce types: "123" is a string, not an integer
- If [RISK_LEVEL] is HIGH, flag any record where you have less than [CONFIDENCE_THRESHOLD] confidence in the extraction as invalid
- Preserve the original input ordering in the errors array
- The `records` array may be empty if no input items pass validation
- The `errors` array may be empty if all input items pass validation

## Input
[INPUT]

## Output Schema
[OUTPUT_SCHEMA]

## Examples
[EXAMPLES]

To adapt this template, replace the square-bracket placeholders with your specific configuration. [OUTPUT_SCHEMA] should contain your target JSON Schema or a plain-text description of field names, types, and constraints. [REQUIRED_FIELDS] should list the fields that cannot be null or absent. [ENUM_VALUES] should map field names to their allowed value sets. [PATTERN_RULES] should specify regex patterns for fields like emails or phone numbers. [CUSTOM_VALIDATION_RULES] can include business logic checks such as "end_date must be after start_date." [DEFAULT_MAP] is optional but useful when you want the model to populate safe defaults for missing optional fields rather than flagging them as errors. [EXAMPLES] should include at least one valid record and one error object to anchor the model's output shape. [REPAIR_MODE] controls whether the model attempts to fix minor issues (like whitespace normalization) and include repaired records in the records array. Set [RISK_LEVEL] to HIGH for regulated domains where false positives in the valid set are unacceptable; this activates the confidence threshold check. [CONFIDENCE_THRESHOLD] should be a value between 0.0 and 1.0 that reflects your tolerance for extraction uncertainty.

Before deploying this prompt, test it with inputs that include at least one fully valid record, one record with a missing required field, one with a type mismatch, and one with an enum violation. Verify that the error objects contain actionable fix_suggestion values and correct retry_priority assignments. In production, always validate the output envelope structure before processing the records array—a malformed envelope should trigger a full retry, not partial ingestion. Wire the errors array into a retry queue that can feed individual failed records back through a repair prompt or a human review interface.

IMPLEMENTATION TABLE

Prompt Variables

Required inputs for the Array Validation-Aware Prompt Template. Each placeholder must be populated before the prompt is sent. Validation notes describe how to check the input before execution.

PlaceholderPurposeExampleValidation Notes

[TARGET_SCHEMA]

Defines the expected shape of each record in the output array, including required fields, types, and constraints.

{"type": "object", "properties": {"id": {"type": "string"}, "score": {"type": "number"}}, "required": ["id", "score"]}

Must be valid JSON Schema. Parse with a JSON Schema validator before injection. Reject if schema has circular references or unsupported keywords for the target model.

[INPUT_RECORDS]

The raw, unvalidated array of records that the model must validate and annotate.

[{"id": "abc", "score": 95}, {"id": "def", "score": "high"}]

Must be a valid JSON array. Check array length; if empty, skip the prompt and return an empty result set. If the array exceeds the model's context window, split into batches.

[ERROR_DEFINITIONS]

A map of error codes to human-readable descriptions and severity levels used to classify validation failures.

{"MISSING_REQUIRED": {"severity": "error", "message": "A required field is missing."}}

Must be a valid JSON object. Every key must be a non-empty string. Severity must be one of 'error', 'warning', or 'info'. Validate against a predefined list of supported error codes.

[VALIDATION_RULES]

Natural language or structured rules that go beyond schema validation, such as cross-field constraints or business logic checks.

"score must be between 0 and 100. If status is 'closed', resolved_date is required."

String input. Check for empty string. For structured rules, parse as JSON and validate rule syntax. If rules reference fields not in [TARGET_SCHEMA], flag as a configuration error before execution.

[OUTPUT_SCHEMA]

The JSON Schema for the final output envelope, including the 'records' array and 'errors' array.

{"type": "object", "properties": {"records": {"type": "array"}, "errors": {"type": "array"}}, "required": ["records", "errors"]}

Must be a valid JSON Schema. The schema must define an object with at least 'records' and 'errors' array properties. Validate that the schema allows for partial success (records array can contain nulls or partial objects if specified).

[MAX_RECORDS_PER_REQUEST]

An integer limit on the number of input records to process in a single model call to manage context window and latency.

50

Must be a positive integer. If [INPUT_RECORDS] length exceeds this value, the harness must split the input into chunks before calling the prompt. Validate that the chunk size plus the prompt overhead fits within the model's context limit.

[RETRY_TARGET_FILTER]

A filter expression that selects which failed records from a previous run should be retried.

"$.errors[*].record_id"

Must be a valid JSONPath or JMESPath expression. Test the expression against a sample error output to ensure it resolves to an array of record identifiers. If null or empty, the prompt runs on the full [INPUT_RECORDS] set.

PROMPT PLAYBOOK

Implementation Harness Notes

How to wire the Array Validation-Aware Prompt Template with Error Objects into a production application, including validation, retries, and partial success handling.

This prompt is designed for a self-validating generation pipeline where the model produces both an array of records and a parallel array of error objects. The implementation harness must treat the model's output as a candidate payload, not a trusted result. After receiving the response, the application layer should parse the JSON, iterate over the records array, and cross-reference each record against its corresponding entry in the errors array using the shared index or record_id. Records with a valid: false flag or a non-empty errors object should be routed to a repair queue, while valid records proceed directly to the downstream system. This design allows partial success: a batch of 100 records where 7 fail validation can still deliver 93 clean records without blocking the entire pipeline.

Validation and Retry Logic: The harness must implement a strict post-processing validator that checks the model's output against the expected schema before trusting the model's self-reported valid flags. A common failure mode is the model marking a record as valid: true while the record still contains a type mismatch or missing required field. Your validator should re-validate every record against the target JSON Schema, regardless of the model's self-assessment. For records that fail, extract the fix_suggestion string from the error object and feed it back into a targeted retry prompt that includes only the failed record and its specific error context—not the entire batch. Limit retries to 2 attempts per record to avoid infinite loops. If a record still fails after retries, log it to a dead-letter queue with the full error object and original input for human review.

Model Choice and Tool Use: This prompt works best with models that have strong JSON mode or structured output capabilities (e.g., GPT-4o with response_format: { type: "json_object" }, Claude 3.5 Sonnet with tool use, or any model supporting constrained decoding). Do not rely on the prompt alone to enforce schema compliance—always pair it with a JSON Schema validator in your application code. For high-throughput pipelines, consider batching records into groups of 20–50 to balance context window usage against retry granularity. If your use case involves regulated data (finance, healthcare, legal), add a human review step for any record where the model's confidence score falls below a configurable threshold or where the error object indicates ambiguity. Log every generation with the prompt version, model ID, input hash, output payload, validation results, and retry count for auditability and prompt regression testing.

IMPLEMENTATION TABLE

Expected Output Contract

Define the exact shape of the validation-aware array output. Every record must include a validation status, and the response must contain a separate error collection for failed records. Use this contract to build downstream retry logic and partial-success handling.

Field or ElementType or FormatRequiredValidation Rule

[RECORDS_ARRAY]

Array of Objects

Must be a JSON array. Can be empty if no records pass validation. Each element must conform to the [RECORD_SCHEMA].

[RECORDS_ARRAY][*].record

Object

Must match the target [RECORD_SCHEMA] exactly. No extra or missing required fields.

[RECORDS_ARRAY][*].validation_status

String (enum)

Must be one of: 'VALID', 'WARNING', 'ERROR'. No other values allowed.

[RECORDS_ARRAY][*].validation_errors

Array of Strings

Required when validation_status is 'ERROR' or 'WARNING'. Must be an empty array or absent when status is 'VALID'.

[ERROR_OBJECTS_ARRAY]

Array of Objects

Must be a JSON array. Contains one entry for every input record that failed validation. Must be empty if all records are valid.

[ERROR_OBJECTS_ARRAY][*].input_index

Integer

Zero-based index referencing the original input record that failed. Must be >= 0 and < length of input batch.

[ERROR_OBJECTS_ARRAY][*].error_code

String

Machine-readable error code (e.g., 'MISSING_REQUIRED_FIELD', 'TYPE_MISMATCH'). Must not be empty.

[ERROR_OBJECTS_ARRAY][*].fix_suggestion

String

Human-readable suggestion for how to fix the record. Can be null if no automated suggestion is possible.

PRACTICAL GUARDRAILS

Common Failure Modes

When generating validated arrays with error objects, these failures surface first in production. Each card identifies a specific breakage pattern and the guardrail that prevents it.

01

Error Object Drift from Validation Schema

What to watch: The model generates error objects with inconsistent field names, missing required error fields, or nested structures that don't match the downstream validation contract. Error payloads become unparseable even when the main records pass. Guardrail: Provide the exact error object schema alongside the record schema in the prompt. Include a [ERROR_SCHEMA] placeholder with required fields like record_index, field, error_code, message, and suggestion. Validate error objects with the same strictness as records.

02

Partial Success Without Retry Targeting

What to watch: The prompt returns 3 valid records and 2 error objects, but the error objects lack enough detail to retry only the failed records. The application must re-process the entire batch, wasting tokens and introducing inconsistency. Guardrail: Require each error object to include a retry_payload field containing the original input or a minimal reconstruction sufficient for single-record retry. Design the retry loop to consume error objects directly without re-extracting from the original input.

03

Validation Status Flag Inconsistency

What to watch: A record appears in the output array with validation_status: "valid" but contains missing required fields or type violations. The status flag and the actual record content disagree, breaking downstream trust in the flag. Guardrail: Add a post-generation validation pass that re-checks every record against the schema regardless of its self-reported status flag. Treat the model's status flag as a hint, not as ground truth. Log mismatches between claimed status and actual validation result for prompt improvement.

04

Error Object Index Mismatch with Record Array

What to watch: Error objects reference record_index: 4 but the output array only contains 3 records, or indices shift when the model drops invalid records from the main array while keeping error objects pointing to original positions. Guardrail: Require error objects to include a stable record identifier from the input rather than relying solely on positional indices. Use input_record_id or a content hash as the primary reference. Validate that every error object's referenced record can be located in either the output array or the input batch.

05

Silent Record Dropping on Validation Failure

What to watch: The model encounters a record it cannot validate and simply omits it from the output array without generating a corresponding error object. The application assumes all inputs were processed, but some records disappeared silently. Guardrail: Add an explicit instruction: 'For every input record, you MUST produce either a valid output record OR an error object. No input record may be silently dropped.' Include a count check in the harness comparing len(input_records) to len(output_records) + len(error_objects).

06

Fix Suggestion Hallucination for Unfixable Records

What to watch: The model generates plausible-sounding fix suggestions for records where the correct value is unknowable, such as a missing transaction amount with no contextual clues. The suggestion looks reasonable but introduces fabricated data into the pipeline. Guardrail: Add a constraint that fix suggestions must include a confidence field and a requires_human_review boolean. For unfixable fields, require the suggestion to be null with requires_human_review: true. Route all human-review-required error objects to a review queue before any automated retry.

IMPLEMENTATION TABLE

Evaluation Rubric

Use this rubric to test the quality of array outputs with error objects before shipping. Each criterion targets a specific failure mode in self-validating generation pipelines.

CriterionPass StandardFailure SignalTest Method

Schema Compliance

Every record in the [OUTPUT_ARRAY] passes JSON Schema validation for the target record type

Validation errors on required fields, type mismatches, or enum violations in any record

Run jsonschema.validate() on each element; fail if any record raises ValidationError

Error Object Presence

Every record in [ERROR_ARRAY] has a non-null error object when [VALIDATION_STATUS] is 'FAILED'

Failed records with null or missing error objects; passed records with populated error objects

Assert error_object is not None iff validation_status == 'FAILED' for all records

Error Object Schema

Each error object contains required fields: [ERROR_CODE], [FIELD_PATH], [MESSAGE], [SEVERITY]

Missing required fields, severity values outside [ERROR, WARN, INFO] enum, or field_path pointing to nonexistent fields

Validate error objects against error schema; check enum membership and field path existence

Fix Suggestion Quality

Fix suggestions in [SUGGESTED_FIX] are actionable and reference specific field values from the invalid record

Vague suggestions like 'fix the value', suggestions referencing fields not present in the record, or null suggestions for ERROR severity

Manual review of 20 random failed records; check that suggestion includes target field name and concrete replacement value

Partial Success Handling

Array output includes all valid records plus error objects for invalid records; no records silently dropped

Total record count in output is less than input count; valid records missing from output; error objects present but corresponding record absent

Assert len([OUTPUT_ARRAY]) + len([ERROR_ARRAY]) == len([INPUT_ARRAY]); verify record IDs match across input and output

Retry Targeting

Error objects include enough context to construct a targeted retry prompt for only the failed records

Error objects lack record identifier, input context, or field-level detail needed to isolate retry to specific records

Extract error objects and attempt to build retry payloads; fail if any retry payload is missing record_id or failed_field_values

Confidence Score Calibration

Confidence scores in [CONFIDENCE] field correlate with actual validation outcomes

High confidence scores on records that fail validation; low confidence on records that pass; missing confidence field entirely

Calculate pass rate by confidence bucket; assert monotonic relationship between confidence and pass rate across buckets

No Hallucinated Fields

Output records contain only fields defined in the target schema; no invented or extra fields

Additional fields present in output records not defined in schema; field names that approximate but don't match schema fields

Compare set of output field names to schema property names; fail if any output field is not in schema

ADAPTATION OPTIONS

Adapt This Prompt

How to adapt

Start with the base prompt but relax strict schema enforcement. Use a simpler output contract: request an array of objects with a valid boolean and an errors string array per record. Skip the retry loop and just log failures.

code
Return a JSON array. Each element must have:
- "record": [OBJECT]
- "valid": boolean
- "errors": string[]

Watch for

  • Model omitting the errors field on valid records instead of returning an empty array
  • Inconsistent error message formats across records
  • Model generating prose explanations outside the error objects
Prasad Kumkar

About the author

Prasad Kumkar

CEO & MD, Inference Systems

Prasad Kumkar is the CEO & MD of Inference Systems and writes about AI systems architecture, LLM infrastructure, model serving, evaluation, and production deployment. Over 5+ years, he has worked across computer vision models, L5 autonomous vehicle systems, and LLM research, with a focus on taking complex AI ideas into real-world engineering systems.

His work and writing cover AI systems, large language models, AI agents, multimodal systems, autonomous systems, inference optimization, RAG, evaluation, and production AI engineering.