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Public story · 2026-08-10 · high
Version 3.9.18 auto-migrates basic-mode users, adds an 83rd MCP tool, and fixes a JSON-RPC spec bug.
Why now: The version lands with lean-ctx's tool count past 80 and CognitiveMode::Full now the default read path, dated August 10.
Version 3.9.18 of lean-ctx made spaced repetition its default context policy, auto-migrating every user still running CognitiveMode::Basic, per the release notes on GitHub.
Two fixes in the same release matter to anyone writing MCP servers, per the notes. The server used to exit on an unknown JSON-RPC method instead of returning MethodNotFound as the spec requires. ctx_patch batches applied partially instead of atomically before this release. Now a batch either fully applies or not at all.
The release also promotes CognitiveMode::Full to default. It wires an FSRS scheduler and Wasserstein-optimal token allocation into the production read path. Graph expansion, verbosity learning and prefetch warming go in alongside it. ctx_cognitive joins as the 83rd tool in lean-ctx's MCP surface.
Spaced repetition was built to schedule human memory review, not to decide what a coding agent keeps in its context window. Using it here reads as an admission that bigger context windows never solved the actual problem: deciding what to forget. Watch whether other context-management tools start citing spaced-repetition research instead of just raising token limits.
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Claude uses MCP / Shared entities / Same source domain / Shared topic / Earlier coverage
Linked by a graph relationship (Claude uses MCP); both cover JSON, MCP; reported by the same outlet (github.com).
MCP deprecates Sampling / Shared entities / Earlier coverage
Linked by a graph relationship (MCP deprecates Sampling); both cover JSON, MCP, RPC; earlier JSON coverage from 2026-07-28.
Linked by a graph relationship (MCP deprecates Sampling); both cover JSON, MCP, RPC; earlier JSON coverage from 2026-07-21.
Linked by a graph relationship (MCP deprecates Sampling); both cover JSON, MCP, RPC; earlier JSON coverage from 2026-07-10.
Claude Code uses MCP / Shared entities / Same source domain / Earlier coverage
Linked by a graph relationship (Claude Code uses MCP); both cover JSON, MCP; reported by the same outlet (github.com).
Context7 uses MCP / Shared entity: MCP / Same source domain / Shared topic / Earlier coverage
Linked by a graph relationship (Context7 uses MCP); both cover MCP; reported by the same outlet (github.com).
Pydantic AI supports MCP / Shared entity: MCP / Same source domain / Shared topic / Earlier coverage
Linked by a graph relationship (Pydantic AI supports MCP); both cover MCP; reported by the same outlet (github.com).
Microsoft supports MCP / Shared entities / Earlier coverage / Tension
Linked by a graph relationship (Microsoft supports MCP); both cover Full, MCP; earlier Full coverage from 2026-07-23.