# Local-first · Tech watch

[Canonical source](<https://sebastien.rigaux.be/en/tech-watch/tags/local-first>)

Applications using local data with persistence and cross-device synchronization.

## [TanStack DB 1.0 RC1: using test oracles to harden agent-written code](<https://sebastien.rigaux.be/en/tech-watch/links/tanstack-db-10-rc1-using-test-oracles-to-harden-agent-written-code>)

TanStack DB reaches 1.0 RC1 after extensive stabilization work. Kyle Mathews explains how **test oracles**—independent models that calculate expected behavior—and property-based testing uncovered bugs in collection updates and the change messages sent to subscribers.

These executable references also give coding agents precise rules to preserve when changing the implementation. The trade-off is clear: writing and refining models takes work, but their simplicity makes complex algorithms easier to verify. The RC also supports incremental adoption, from existing REST APIs to local persistence, offline mutations, and real-time sync.

2026-10-30 · [Markdown](<https://sebastien.rigaux.be/en/tech-watch/links/tanstack-db-10-rc1-using-test-oracles-to-harden-agent-written-code.md>) · [Original resource](<https://tanstack.com/blog/tanstack-db-1.0-rc1-going-all-in-on-oracles>)

## [Engram: persistent memory for MCP-compatible AI agents](<https://sebastien.rigaux.be/en/tech-watch/links/engram-persistent-memory-for-mcp-compatible-ai-agents>)

Engram provides **persistent memory** for AI agents, compatible with any agent supporting the MCP protocol (Claude Code, Gemini CLI, Codex, VS Code, etc.). The tool runs as a single Go binary with no external dependencies, storing memories in a SQLite file with built-in FTS5 search. It features a TUI, Git sync, and a self-hostable cloud extension, while remaining local-first and open source under the MIT license.

2026-10-16 · [Markdown](<https://sebastien.rigaux.be/en/tech-watch/links/engram-persistent-memory-for-mcp-compatible-ai-agents.md>) · [Original resource](<https://engram.gentlemanprogramming.com/>)

## [TinyBase for reactive, local-first JavaScript apps](<https://sebastien.rigaux.be/en/tech-watch/links/tinybase-for-reactive-local-first-javascript-apps>)

TinyBase is a reactive in-memory store for JavaScript and TypeScript apps, with persistence and synchronization. It provides building blocks for local-first experiences without prescribing one server architecture.

2026-03-08 · [Markdown](<https://sebastien.rigaux.be/en/tech-watch/links/tinybase-for-reactive-local-first-javascript-apps.md>) · [Original resource](<https://tinybase.org/>)

## [Persist TinyBase data in a SQL database](<https://sebastien.rigaux.be/en/tech-watch/links/persist-tinybase-data-in-a-sql-database>)

The guide lists TinyBase persisters for SQLite environments, PostgreSQL and SQL Server. It helps match an adapter to the application’s runtime and storage choice.

2025-07-18 · [Markdown](<https://sebastien.rigaux.be/en/tech-watch/links/persist-tinybase-data-in-a-sql-database.md>) · [Original resource](<https://tinybase.org/guides/persistence/database-persistence/>)

## [Synchronize a local-first Expo application with TinyBase](<https://sebastien.rigaux.be/en/tech-watch/links/synchronize-a-local-first-expo-application-with-tinybase>)

This guide introduces TinyBase into an Expo application to combine reactive local data with synchronization. It covers sharing data across devices and users.

2024-10-06 · [Markdown](<https://sebastien.rigaux.be/en/tech-watch/links/synchronize-a-local-first-expo-application-with-tinybase.md>) · [Original resource](<https://expo.dev/blog/how-to-synchronize-reactive-local-first-apps-with-tinybase>)