LeanCTX
yvgude
Local Rust 'context layer' that compresses file reads and shell output for coding agents over MCP.
What is LeanCTX?
A single local Rust binary that acts as a context layer between AI coding agents and their environment: it compresses file reads and shell output, caches results, keeps persistent session memory, enforces file-access limits and secret/injection defence, and tracks token budgets on a dashboard. It exposes dozens of MCP tools and connects to 30+ agents over MCP.
Pros & Cons
Pros
- A single dependency-free Rust binary with broad install and SDK coverage and 30+ MCP-agent compatibility
- Local-first with explicit security controls (path jail, secret/injection defence, zero telemetry)
- Very active development (200+ releases) on an Apache-2.0 core
Cons
- Token-savings percentages and install counts are unverified project claims; the 'provable savings' ledger is self-reported
- Open-core: some value sits behind paid tiers, so 'open source' needs the local-use asterisk
- Dozens of tools and read modes are real configuration surface to learn
License
Apache-2.0 (OSI-open)
Apache-2.0 and free for local use forever; some features sit behind paid Builders/Teams/Enterprise tiers (open-core).
When it is interesting
An agent burns context on large file reads and noisy shell output and you want a local, MCP-drop-in compression layer.
When it is too early
If you need independently verified token-reduction numbers, or want everything OSI-open with no commercial tier.
This repo featured in the 2026-07 edition of the Open-Source AI Radar.
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