Klaar

klaar (plattdüütsch/low german) — "clear, ready" — as in "klaar kommen" (to manage, to handle). A universal AI coding agent optimizer that makes agents klaar to work.

License: MIT OR Apache-2.0 Language: Rust Runtime: Local-first

klaar is a single-binary, local Model Context Protocol (MCP) server that equips AI coding agents (such as Google Antigravity, Claude Code, or any MCP-compatible environment) with persistent, hybrid-search memory and localized development guardrails. Running local-first with zero runtime network dependencies (model weights are downloaded once on first run if semantic-search is enabled), it embeds an intelligence suite directly inside the agent's stdio lifecycle.

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🚀 Why klaar?

AI coding agents are powerful, but they suffer from significant operational inefficiencies:

• Context Bloat: They read entire 1000-line files to locate a single method signature.
• Aggressive Rewrites: They rewrite whole files to apply a 3-line bug fix, wasting tokens and causing compile errors.
• Amnesia: They forget design decisions, auth strategies, and conventions between conversation sessions.
• Brittle Pushes: They attempt to push code to remote branches without running local verification, breaking CI/CD pipelines.

klaar solves all four problems natively with 13 MCP tools and local utilities:

Feature Area	MCP Tool	What it does	Expected ROI
Context Compression	surgical_read	Reads files in skeleton, compressed, or full mode to reduce unnecessary context.	Lower token usage for navigation-heavy tasks
Localized Patching	fast_apply	Validates and applies bottom-up line hunks without rewriting entire files.	Smaller edits, fewer rewrite regressions
Hybrid Memory Recall	recall_memory	Runs SurrealDB hybrid semantic + lexical retrieval fused via Reciprocal Rank Fusion (RRF).	Better recall across semantic and exact-match queries
Decision Intelligence	record_decision / get_why	Tracks architectural decisions, file scopes, and confidence decay as code changes.	Less decision drift across sessions
CI/CD Guardrails	pre_push_check	Runs target checks from .klaar/targets.toml with timeout and bounded output.	Earlier failure detection before push

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📊 Token ROI Tracking

klaar stats reports token savings and usage from its embedded ledger. Example output:

AGENT                     | PROJECT                   |    TOKENS SAVED |    TOTAL TOKENS |  % SAVED
--------------------------+---------------------------+-----------------+-----------------+---------
antigravity               | my-project                |           11962 |           12422 |    96.3%
antigravity-system        | klaar_internal            |            2951 |               0 |     0.0%
antigravity-system        | my-project                |            9822 |            5187 |   189.4%
planning-agent            | my-project                |            3490 |            3638 |    95.9%
copilot-agent             | my-project                |             912 |            1005 |    90.7%
--------------------------+---------------------------+-----------------+-----------------+---------
TOTAL                     |                           |           29409 |           22616 |   130.0%

[!NOTE] This is an example snapshot. Actual savings depend on repository shape, agent behavior, and tool usage patterns. Disclaimer: These ROI numbers are recorded from specific, internal development sessions under targeted agent workflows. They are illustrative of potential savings and do not represent controlled, standardized open-source benchmarks.

[!TIP] How savings are tracked: klaar calculates raw token savings by measuring the difference between the full source file and the compressed/skeleton stream returned. Real-world savings vary depending on whether the agent requests follow-up reads for full files.

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🛠️ Core Upgrades & Architectural Pillars

1. Decision Intelligence (Repowise-Inspired)

Unlike flat keyword-based memory stores, klaar links architectural decisions directly to the specific source files they govern.

• Confidence Decay: As governed files are modified via fast_apply, their governing decisions automatically decay in confidence (by 0.1 per edit).
• Self-Healing Verification: When an agent inspects files, it calls get_why() to retrieve active decisions. Once it verifies they are still valid, it calls confirm_decision() to restore the confidence score to 1.0.
• Co-Change Tracker: Tracks groups of files frequently committed together, alerting agents to cross-component implications.

2. Native Hybrid Search with Reciprocal Rank Fusion (RRF)

klaar integrates local vector embeddings with lexical BM25 full-text indexing, fusing results using mathematical Reciprocal Rank Fusion (RRF):

• Semantic Layer: Generates 384-dimensional vector embeddings locally using the ONNX-backed BGESmallENV15 model (no external API keys; first run may download model weights).
• Lexical Layer: Computes full-text search scores using a BM25 snowball english stemming analyzer.
• Rust Fusion Engine: Results are merged server-side using the standard RRF formula: $$Score = \sum_{d \in D} \frac{1.0}{60.0 + Rank_d}$$ This automatically balances conceptual matching with exact symbol names, error codes, and line numbers.

3. Asynchronous Cache & Proactive Invalidation

• Serves repeated file reads and symbols via an asynchronous moka cache with $O(1)$ key lookups.
• Backed by a recursive notify filesystem watcher that proactively invalidates cache entries the moment external edits occur.

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📦 Installation & Setup

Prerequisites

• Rust toolchain (rustup.rs)

1. Run the Installer

git clone https://github.com/NMA-vc/klaar.git
cd klaar
./install/setup.sh

The installer will:

1. Compile the codebase in fully optimized release mode (cargo build --release).
2. Copy the binary to /usr/local/bin (uses sudo when needed).
3. Automatically detect and register the MCP server with your active AI environments:
   • Google Antigravity: ~/.gemini/antigravity/mcp_config.json
   • Claude Code: ~/.config/claude/claude_desktop_config.json

2. Initialize a Project

To configure klaar checks inside your coding project:

klaar install --project /path/to/your-project

This generates a localized .klaar/targets.toml file in your root folder.

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⚙️ Configuration Reference

Project Config (.klaar/targets.toml)

Placed in your project root, this defines test gates and deploy pathways per target:

[project]
name = "my-rust-app"
language = "rust" # "rust" | "typescript" | "mixed"

[[targets]]
name = "production"
pre_push_checks = [
  "cargo check --workspace",
  "cargo clippy -- -D warnings",
  "cargo test --workspace"
]
deploy_command = "dokploy deploy --app my-app-prod"

Global Config (~/.config/klaar/config.toml)

Customizes path sandboxing, memory locations, and trusted execution limits:

db_path          = "~/.local/share/klaar/db" # default location
log_level        = "info"                    # logging filter
allowed_roots    = ["/Users/username/projects"]  # Sandbox file reads/writes
trusted_projects = ["/Users/username/projects/my-project", "/Users/username/projects/klaar"] # Paths allowed to run checks
deny_when_unconfigured = true                # Secure-by-default fail-closed setting

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🔒 Security & Sandboxing Guidelines

klaar enforces a secure-by-default, fail-closed sandboxing model to ensure that AI agents only read/write files and execute commands in designated directories.

Fail-Closed Default (deny_when_unconfigured = true)

If the list of allowed_roots or trusted_projects is empty or the configuration file is missing, klaar will deny all access requests and throw an error. This prevents newly installed agents from reading sensitive system directories or running random push commands before you have explicitly authorized them.

Step-by-Step Security Setup

To authorize an agent to work on your projects:

1. Open the global config file ~/.config/klaar/config.toml.
2. Add your development parent directory to allowed_roots (this enables surgical_read, fast_apply, grep, and ls operations):

   allowed_roots = ["/Users/yourname/Projects"]
   

3. Add the specific repositories where you want klaar to run tests and pre-push hooks to trusted_projects:

   trusted_projects = [
     "/Users/yourname/Projects/my-rust-app",
     "/Users/yourname/Projects/klaar"
   ]
   

4. If you intentionally want to turn off the sandbox and fail-open with warnings (not recommended for production), you can explicitly set:

   deny_when_unconfigured = false
   

Note: trusted_projects is an MCP guardrail — it restricts which repositories AI agents can execute commands in via the pre_push_check tool. It provides no additional security boundary for direct CLI invocations by the local user, who already has full shell access.

For detailed disclosures and threat models, see SECURITY.md.

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🧰 MCP Tool Specifications

surgical_read

Reads a file in skeleton, compressed, or full mode.

• Request: { "file_path": "/src/main.rs", "mode": "skeleton", "agent_id": "agent-1" }
• Response: Signature-focused or compressed content to reduce context bloat.

fast_apply

Applies discrete hunks of edits, validating boundaries bottom-up.

• Request: { "file_path": "/src/lib.rs", "hunks": [{ "line_start": 10, "line_end": 12, "new_content": "let x = 42;" }], "agent_id": "agent-1" }

store_memory

Saves a structured memory inside the local SurrealDB instance.

• Request: { "key": "jwt-cookie", "content": "Cookie: __Secure-authjs.session-token", "tags": ["jwt", "cookie"], "project": "my-project" }

recall_memory

Performs fused vector + BM25 RRF search.

• Request: { "query": "cookie authentication", "project": "my-project", "limit": 3 }

grep

Runs a token-optimized codebase search, grouping matches by file and stripping redundant whitespace.

• Request: { "query": "surgical_read", "project_path": "/Users/username/projects/klaar", "case_insensitive": true, "include_glob": "*.rs" }

ls

Noise-filtered tree-based directory listing, automatically excluding target, node_modules, and similar artifacts.

• Request: { "project_path": "/Users/username/projects/klaar", "max_depth": 2 }

find_symbol

Fast definition lookup across the project using tree-sitter indices.

• Request: { "symbol": "surgical_read", "project_path": "/Users/username/projects/klaar" }

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🔍 Trust, Security, & Testing Disclosures

Known Security Advisories & Policy Exceptions

• RUSTSEC-2026-0002 (Transitive lru Unsoundness): This warning is policy-ignored inside .cargo/audit.toml. It is a transitive dependency of the fastembed library. The unsoundness refers to potential concurrent race conditions in thread-unsafe lru operations. Because klaar executes the embedder in isolated tasks with strictly controlled single-threaded access patterns, this is non-exploitable in our host runtime environment. Downstream users requiring a 100% warning-free supply chain out of the box can build klaar without its default semantic search feature (cargo build --release --no-default-features).

Test Coverage & Integration Verification

• Test Coverage Gap: While CONTRIBUTING.md establishes a target of 100% coverage for newly added logic, our current core integration test suite has a thin baseline (7 comprehensive end-to-end integration and stress tests). Expanding our integration and load testing matrix across all dispatchers is a high-priority item on our public roadmap, and we actively welcome community contributions in this area!

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📄 License

Dual-licensed under either:

• MIT License (LICENSE-MIT or http://opensource.org/licenses/MIT)
• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)

Choose the license that best fits your development or corporate integration goals.