--- title: "Error Model Validation Architect: review, setup & limitations · Undominated.ai" canonical: https://undominated.ai/skills/jetbrains-error-model-validation-architect/ description: "Turns ad-hoc exception handling into a deliberate public error contract: an explicit taxonomy across eight failure categories, status-code mapping rules, machine-readable codes separated from human messages, framework exception coverage, and a logging rule that keeps internal detail out of client payloads." --- # Error Model Validation Architect: review, setup & limitations · Undominated.ai > Turns ad-hoc exception handling into a deliberate public error contract: an explicit taxonomy across eight failure categories, status-code mapping rules, machine-readable codes separated from human messages, framework exception coverage, and a logging rule that keeps internal detail out of client payloads. [← Explore all skills](/skills/) API DESIGN / JetBrains # Error Model Validation Architect Turns ad-hoc exception handling into a deliberate public error contract: an explicit taxonomy across eight failure categories, status-code mapping rules, machine-readable codes separated from human messages, framework exception coverage, and a logging rule that keeps internal detail out of client payloads. [See setup guidance ↓](#setup)[Original source ↗](https://github.com/JetBrains/skills/tree/e0f258b5cfed145015cb3e48da9a97947f7c4ed7/error-model-validation-architect) SOURCE REVIEW Reviewed 2026-10-13 Evidence 6 linked sources Publisher JetBrains Licence [MIT (upstream Kotlin backend agent skills) ↗](https://github.com/yalishevant/kotlin-backend-agent-skills/blob/fd0ed521d22efd28221d532c9abab97af0b9bf0e/LICENSE) Revision e0f258b5cfed [Read what was—and wasn’t—checked ↓](#review) “Design and implement consistent API validation and error-handling behavior for Kotlin plus Spring services. Use when defining error payloads, mapping framework and domain exceptions, standardizing HTTP status codes, adding `@ControllerAdvice`, preventing internal-detail leakage, or ensuring clients can rely on stable machine-readable error semantics across endpoints.” [JetBrains · upstream description ↗](https://github.com/JetBrains/skills/blob/e0f258b5cfed145015cb3e48da9a97947f7c4ed7/error-model-validation-architect/SKILL.md) Our analysis follows below. 01 / THE REASONING ## Why this made the selection. - Forces an explicit error taxonomy before any code — at minimum eight categories from malformed request to downstream dependency failure — and forbids collapsing every non-success outcome into one generic envelope. - Pins specific status-code decisions: 409 for idempotency-key and uniqueness races, 422 for structurally valid but business-invalid payloads, and downstream 500s that must not blindly become your own 500. - Separates the two audiences of an error — the client who needs to recover and the operator who needs to diagnose — and makes leaking stack traces, SQL fragments, class names or tokens a named guardrail. ### A good fit for - Designing a stable, versionable error envelope for a service whose clients integrate against it - Auditing an existing @ControllerAdvice for status-mapping mistakes and internal-detail leakage - Deciding aggregation versus first-failure semantics for field-level validation errors ### Weigh up before choosing - The worked context is Kotlin plus Spring (Bean Validation targets, @ControllerAdvice, security entry points); the taxonomy method transfers, the framework specifics do not. - Produces a design and implementation plan with named tests to write, not running code. - RFC 7807 Problem Details is handled as a set of contract decisions, not a full tutorial on the spec. - The author: Kotlin credit is added by the JetBrains mirror. The upstream SKILL.md names no author, and the upstream repository now sits under the personal account yalishevant with an MIT licence naming Anton Yalyshev. - The JetBrains/skills README disclaims the catalogue as provided for demonstration and educational purposes only and asks you to test each skill before relying on it. - The upstream repository moved: https://api.github.com/repos/Kotlin/kotlin-backend-agent-skills now returns yalishevant/kotlin-backend-agent-skills, a personal account (checked 2026-10-13). The pins and the MIT licence are unchanged. 02 / THE REVIEW RECORD ## What we actually inspected. Source review has boundaries. A clear record is more useful than a “safe” badge. ### Material inspected - error-model-validation-architect/SKILL.md (JetBrains mirror) - error-model-validation-architect/agents directory listing - upstream yalishevant/kotlin-backend-agent-skills .agents/skills/error-model-validation-architect/SKILL.md - upstream LICENSE - JetBrains/skills README mirror policy - https://github.com/Kotlin/kotlin-backend-agent-skills (answers HTTP 301 to yalishevant/kotlin-backend-agent-skills) - mirror SKILL.md diffed against the upstream SKILL.md at fd0ed521d22efd28221d532c9abab97af0b9bf0e ### Our findings - The output contract demands six named sections (taxonomy, status mapping, payload shape, framework coverage, implementation plan, logging rule), which makes a run reviewable against its own claims. - Names the exact framework exceptions a stable contract must handle explicitly — MethodArgumentNotValidException, HttpMessageNotReadableException, type-mismatch, missing-parameter, and the security entry points — rather than trusting defaults. - A diff against the upstream SKILL.md at fd0ed521d22efd28221d532c9abab97af0b9bf0e shows the mirror adds four frontmatter lines (metadata, short-description, author: Kotlin, source) and nothing else; the upstream file has no author field. agents/openai.yaml is identical in both. - Upstream health: https://github.com/Kotlin/kotlin-backend-agent-skills, which the mirror’s metadata.source and README name, now answers HTTP 301 to yalishevant/kotlin-backend-agent-skills, a personal account (https://api.github.com/repos/Kotlin/kotlin-backend-agent-skills returns full_name yalishevant/kotlin-backend-agent-skills, owner type User). fd0ed521d22efd28221d532c9abab97af0b9bf0e is still that repository’s head, and its LICENSE (MIT, copyright 2026 Anton Yalyshev) is unchanged (checked 2026-10-13). ### Not established by this review - No error model was implemented or served; the design rules were read, not executed. - The agents/openai.yaml companion file was noted but not exercised. The review applies to the material and revision named here. A newer upstream release can change its behavior. 03 / PUT IT TO WORK ## Add a skill to your workflow. [Upstream setup instructions ↗](https://github.com/vercel-labs/skills/blob/7407f3893ad4dceab546ac002c3ef806e4000c73/README.md) DOCUMENTED COMMAND npx skills add JetBrains/skills/error-model-validation-architect --skill error-model-validation-architect Copy command ↗ Run in your terminal to choose your AI tools, project or global scope, and installation method. This short command follows the current upstream version; the review covers the revision shown above. Optional: install the reviewed revision Keeps the original source and installer version where recorded, while leaving your AI tools and installation scope for you to choose. npx skills add https://github.com/JetBrains/skills/tree/e0f258b5cfed145015cb3e48da9a97947f7c4ed7/error-model-validation-architect --skill error-model-validation-architect Copy reviewed-revision command ↗ - Install the skill from the JetBrains mirror, or from the upstream Kotlin backend agent skills repository if you prefer the origin. - Bring the endpoint contracts, current exception classes and any existing error payloads; the output contract expects them as inputs. ### Before you start - Node.js/npm for the installer - An agent that supports the Agent Skills format - The API whose error contract is being designed or audited ### Compatibility Agent Skills-compatible coding agents · Kotlin plus Spring services for the worked examples · Any HTTP API designing an error contract ### Reads endpoint contracts and exception classes; writes an error-model design - Read API contracts, DTOs, validators and exception handling code - Write design documents and planned code changes - No network access is required by the workflow ### Cost model MIT-licensed instruction package; the design runs locally in the agent. 04 / FOLLOW THE EVIDENCE ## The source trail. Our notes are separate from the original resource. Check upstream before adopting a new version. - [Skill definition at reviewed revision ↗](https://github.com/JetBrains/skills/blob/e0f258b5cfed145015cb3e48da9a97947f7c4ed7/error-model-validation-architect/SKILL.md) Checked 2026-10-13 https://github.com/JetBrains/skills/blob/e0f258b5cfed145015cb3e48da9a97947f7c4ed7/error-model-validation-architect/SKILL.md Supports: summary, upstreamDescription, whySelected, bestFor, limitations, review, access - [Upstream skill definition (origin of the mirrored content) ↗](https://github.com/yalishevant/kotlin-backend-agent-skills/blob/fd0ed521d22efd28221d532c9abab97af0b9bf0e/.agents/skills/error-model-validation-architect/SKILL.md) Checked 2026-10-13 https://github.com/yalishevant/kotlin-backend-agent-skills/blob/fd0ed521d22efd28221d532c9abab97af0b9bf0e/.agents/skills/error-model-validation-architect/SKILL.md Supports: review, whySelected, limitations - [Upstream license (MIT) ↗](https://github.com/yalishevant/kotlin-backend-agent-skills/blob/fd0ed521d22efd28221d532c9abab97af0b9bf0e/LICENSE) Checked 2026-10-13 https://github.com/yalishevant/kotlin-backend-agent-skills/blob/fd0ed521d22efd28221d532c9abab97af0b9bf0e/LICENSE Supports: license - [Former upstream location (HTTP 301 to yalishevant/kotlin-backend-agent-skills) ↗](https://github.com/Kotlin/kotlin-backend-agent-skills) Checked 2026-10-13 https://github.com/Kotlin/kotlin-backend-agent-skills Supports: review, limitations - [Mirror policy: JetBrains-filtered, JetBrains-verified snapshot with source links and CI skill scanning ↗](https://github.com/JetBrains/skills/blob/e0f258b5cfed145015cb3e48da9a97947f7c4ed7/README.md) Checked 2026-10-13 https://github.com/JetBrains/skills/blob/e0f258b5cfed145015cb3e48da9a97947f7c4ed7/README.md Supports: review, install, limitations - [Skills installer source formats and selective installation ↗](https://github.com/vercel-labs/skills/blob/7407f3893ad4dceab546ac002c3ef806e4000c73/README.md) Checked 2026-10-13 https://github.com/vercel-labs/skills/blob/7407f3893ad4dceab546ac002c3ef806e4000c73/README.md Supports: install KEEP COMPARING ## Other approaches to consider. Related by category or shared topics. These are alternatives to inspect, not a measured quality order. [### Integration Resilience Engineer ↗ Designs resilient HTTP, messaging and scheduled integrations: timeout budgets derived from the caller’s SLO, retryable-versus-terminal failure classification, idempotency and deduplication, circuit breakers, DLQ behaviour, and distributed locking for scheduled jobs.](/skills/jetbrains-integration-resilience-engineer/)[### Protobuf gRPC API Review ↗ Reviews .proto and gRPC changes as long-lived contracts across binary wire, JSON and text formats, generated APIs and runtime behavior, with mixed-version rollout tracing and a four-rung verdict.](/skills/github-protobuf-grpc-api-review/)[### Azure validate ↗ Pins Microsoft's pre-deploy Azure check, which stops without an approved plan and will not run azd deploy itself.](/skills/microsoft-azure-validate/) [AI Tools ↗](/tools/)[Skills ↗](/skills/)[Agents ↗](/agents/)[MCP Servers ↗](/mcp-servers/)[Workflows ↗](/workflows/) ## Continue your investigation - [Choose a toolkit](/tools/) - [Inspect execution hosts](/agents/) - [Check tool access](/mcp-servers/) - [Check project dependencies](/check-repo/)