**Thread URL:** https://www.perplexity.ai/search/[thread-url-to-be-added]
**File URL:** https://paregrinus.ai/archive/threads/external-storage-formats.md
**Date:** 2026-04-21

**Summary:** Evaluates external data storage formats for thread memory against three criteria: reliable findability (stable crawlable URLs), completeness and accuracy (data quality as primary RAG determinant), and manageable length (100–200 token summaries). Recommends Markdown-KV as primary format (highest LLM comprehension at 60.7%), JSON as secondary metadata layer for local LLM portability, one file per thread at a stable URL, and the master index functioning as a semantic cluster map enabling two-tier retrieval. Thread discipline — focused sessions — is identified as a prerequisite for useful records.

**Keywords:** Markdown-KV, JSON metadata, RAG retrieval, chunk size, two-tier retrieval, thread discipline, stable URL, semantic cluster map, token budget, autonomous maintenance

**Related:** /archive/threads/database-record-structure.md, /archive/threads/rag-architecture-retrieval.md