Claude returned ```json blocks 14% of the time. Here is the Rust crate I wish I had earlier.
The article discusses the challenges of obtaining valid JSON responses from the Claude AI model. It highlights that 14% of the responses were not parseable as JSON due to various issues. To address this, the author created a Rust crate called llm-json-repair that performs three passes to clean up the responses before they are processed further.
- ▪Claude AI returned valid JSON 86% of the time during structured-output calls.
- ▪Common issues included JSON wrappers, leading or trailing prose, and trailing commas.
- ▪The llm-json-repair crate performs three passes to clean up the responses, improving their parseability.
DEV.to (Top) files mainly under programming. We currently carry 4,924 of its stories.
Story provenance
Source · retrieval · rights · ranking — open for full record
inspect →
Story provenance
Attribution is not the same as permission. This drawer separates discovery metadata, excerpts, WeSearch-generated summaries, reuse status, and whether the publisher receives the visit. Nothing here claims a legal grant the publisher has not made.
Record
| Original publisher | DEV.to (Top) |
| Canonical URL | https://dev.to/mukundakatta/claude-returned-json-blocks-14-of-the-time-here-is-the-rust-crate-i-wish-i-had-earlier-4dp6 |
| Publication time | Thu, 21 May 2026 01:52:16 +0000 |
| Retrieval time | 2026-05-21T02:05:03.425Z |
| Last seen | 2026-05-21T02:05:03.425Z |
| Headline source | Publisher (no WeSearch rewrite) |
| Excerpt source | publisher body |
| Excerpt method | First ~120 words (~800 chars) of extracted publisher body, fair-use limited. |
| Summary | WeSearch · cerebras-chat (WeSearch summarizer) |
| Summary source text | contentText |
| Citation coverage | Summary is a WeSearch-generated derivative; primary citation is the original publisher URL. |
| Cluster | iDF7RWaycrHn |
| Cluster logic | Grouped by semantic title/content similarity across sources within a rolling window. Same-publisher template collisions are excluded from coverage comparison. |
| Ranking reason | Story pages are not engagement-ranked. Hub feeds use recency, with optional source-diversified chronological ordering (cap consecutive stories per source). No personalized ranking. |
| Publisher visit | Yes — open original |
| Substitutes article? | No — link-out required for full text |
Rights status (four layers)
WeSearch handling by dimension
| Indexing | May the item be indexed (stored, ranked, made findable)? | Allowed |
| Snippet | May a short excerpt of the publisher's text be shown? | Allowed |
| AI summary | May WeSearch generate its own short summary of the article? | Limited |
| Retrieval / RAG | May the content be exposed for third-party retrieval-augmented generation? | Not asserted |
| Model training | May the content be used to train AI models? | Not asserted |
| Commercial reuse | May the content be reused commercially? | Not permitted |
Basis: Derived from the published RSS/Atom feed. Contact: [email protected]. Reviewed: 2026-07-24.
Opening excerpt (first ~120 words) tap to expand
try { if(localStorage) { let currentUser = localStorage.getItem('current_user'); if (currentUser) { currentUser = JSON.parse(currentUser); if (currentUser.id === 3915555) { document.getElementById('article-show-container').classList.add('current-user-is-article-author'); } } } } catch (e) { console.error(e); } Mukunda Rao Katta Posted on May 21 Claude returned ```json blocks 14% of the time. Here is the Rust crate I wish I had earlier. #hermesagent #ai #llm #rust I had a system prompt that ended with: Reply with only a JSON object. Do not include code fences. Do not include explanation. That should be enough. It is not.
…
Excerpt limited to ~120 words for fair-use compliance. The full article is at DEV.to (Top).
Discussion
0 commentsMore from DEV.to (Top)
