Behavior Runtime MCP

io.github.putervisionPublished by GitHub account putervisionv0.4.1Updated Oct 24, 2026

In-browser ~60Hz behavior tree execution engine with reactive triggers and blackboard projection.

VerifiedSTDIODesktop onlyBrowser AutomationDeveloper Tools

Overview

AI-generated overview

A local MCP server that runs deterministic behavior trees in browser runtimes at about 60Hz, letting an assistant load, control, inspect and audit those trees.

What you can do
Load, swap and unload behavior trees in a browser runtime, and register, get or list immutable tree JSON with SHA-256 hashes. Set, query and reset runtime parameters, and read current status, history, tree state, tick counts and durations. Abort, pause or resume executions, and register or list reactive interrupt triggers with priority preemption. Capture and list deterministic browser action recordings, and read current or historical telemetry, tick durations and stuck events. Read and write shared blackboard variables, and run SQLite diagnostics, SHA-256 Merkle audits, snapshots and checkpoint rollback.
When to use it
Useful when you want an assistant to drive or supervise high-frequency, deterministic behavior-tree logic in a browser, such as game-like agent behavior, reactive trigger handling, or replaying and auditing recorded action sequences.
Requirements
Runs as a local process over stdio, installed from the npm package and started with the run command. The README's client configuration sets the PENTAD_HMAC_SECRET environment variable for signed dispatch tokens. The README also describes CLI commands for initialization, diagnostics and inspection.
Before you install
The README's configuration requires a shared secret in PENTAD_HMAC_SECRET, which must be kept private. Tools can write and change runtime state: loading or swapping trees, setting parameters, aborting or pausing executions, writing blackboard variables, and restoring snapshots. It executes actions in a browser runtime, so review the guardrails and leaf policies before letting it act.

Installation

In SourceWeft

  1. Open Behavior Runtime MCP in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

@putervision/behavior-mcp

[npm version] [version] [CI] [Node] [License: MIT]

High-Frequency (~60Hz) In-Browser Behavior Tree Tactical Runtime Engine for AI Agents

@putervision/behavior-mcp is a Model Context Protocol (MCP) server that executes deterministic behavior trees directly in browser runtimes at ~60Hz with reactive trigger preemption, frame recordings, SHA-256 Merkle audit chains, and a 5-layer safety guardrail stack.

🌐 Official Documentation: putervision.com • Interactive Web Docs

⚡ 15-Second Quick Start

bash
# 1. Initialize runtime & seed default behavior trees in your workspacenpx @putervision/behavior-mcp init
# 2. Run system diagnostic and health checksnpx @putervision/behavior-mcp doctor
# 3. Inspect active executions, blackboard state, and reactive triggersnpx @putervision/behavior-mcp inspect

🛠️ 10 Core MCP Tools

ToolActionsPurpose
load_behaviorload, unload, swapInject, initialize, or hot-swap a behavior tree in browser runtime
set_parametersset, get, resetDynamically update or query runtime execution parameters
get_statuscurrent, history, tree_stateQuery active status, node traversal path, tick count, duration
abort_behaviorabort, pause, resumeHalt, pause, or resume behavior execution safely
register_triggerregister, listConfigure reactive interrupt triggers with priority preemption
replay_recordingcapture, listCapture or inspect deterministic browser action sequences
get_metricscurrent, historyRetrieve runtime telemetry, tick durations, and stuck events
manage_behaviorsregister, get, listCRUD for immutable behavior tree JSON with SHA-256 tree hashes
manage_blackboardget, setRead, write, or query shared behavior tree blackboard variables
manage_runtime_dbstats, audit, snapshot, restoreSQLite diagnostics, SHA-256 Merkle audit, and checkpoint rollback

🛡️ 5-Layer Safety Guardrail Stack & System 1 Invariants

  1. Fail-Closed Evaluator: Unrecognized node definitions throw fatal exceptions immediately.
  2. 60Hz Tick Invariant & Synchronous semantic_check: The loop never blocks on external network calls; semantic condition checks resolve synchronously against blackboard caches.
  3. HMAC Intention Gate Verification: Intentions dispatched to execution nodes require unexpired, cryptographically signed dispatch tokens (PENTAD_HMAC_SECRET).
  4. Action Rate Limiter & Leaf Policy Gate: Strict 60 actions/sec maximum throughput ceiling and policy guardrails blocking irreversible mutations.
  5. Emergency Kill Switch & Watchdog Heartbeat: Atomic safety latch and watchdog timers halting execution if tick stalls beyond 5,000ms.

📚 Deep Documentation Guides

🔗 Client Configuration & Environment

Add to .cursor/mcp.json or .vscode/mcp.json:

json
{  "mcpServers": {    "behavior-mcp": {      "command": "behavior-mcp",      "args": ["run"],      "env": {        "PENTAD_HMAC_SECRET": "your-secure-shared-secret-here"      }    }  }}

🧪 Testing

bash
# Run full unit and integration test suite across 38 test files (266 tests)npm test

📄 License

MIT © PuterVision

Source: README.md at commit b86e6d7

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

5
  1. v0.4.1LatestOct 3, 2026
  2. v0.4.0Oct 2, 2026
  3. v0.3.1Sep 29, 2026
  4. v0.3.0Sep 26, 2026
  5. v0.2.1Sep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts