blockout-mcp

MCP (Model Context Protocol) stdio bridge for Blockout — the open-source previs desktop app for AI filmmaking. With this server connected, an AI agent can stage grey-box worlds, drop in choreographed crowds, animate characters, frame and move the camera with classic cinematography presets, scrub the timeline, take viewport screenshots, and drive exports — everything a human does in the app.

Zero dependencies. Node ≥ 18. One file.

Requirements

1. The Blockout desktop app must be running with a project open. Get it from the Blockout repo (build from source or use a release DMG).

2. On launch, Blockout starts a localhost-only control server on a random port and writes a discovery file to ~/.config/blockout/control.json (random bearer token, mode 0600, removed on quit). This bridge reads that file automatically — there is nothing to configure and no credentials to enter.

Related MCP server: nexus3d

Connect

Hermes

Add to ~/.hermes/config.yaml (or install from the Hermes MCP catalog once listed):

mcp_servers:
  blockout:
    command: "node"
    args: ["/absolute/path/to/blockout-mcp/blockout-mcp.mjs"]

Claude Code

claude mcp add blockout -- node /absolute/path/to/blockout-mcp/blockout-mcp.mjs

Any MCP client (generic stdio config)

{ "mcpServers": { "blockout": { "command": "node", "args": ["/absolute/path/to/blockout-mcp/blockout-mcp.mjs"] } } }

Tools (30)

get_state · list_assets · add_entity · move_entity · delete_entity · add_actor_mark · add_camera_mark · clear_camera_marks · set_shot · new_shot · apply_framing · list_camera_moves · apply_camera_move · set_track_subject · list_action_presets · apply_action_preset · list_sequence_styles · spawn_sequence · set_reference · snap_to_ground · set_time · play · stop · screenshot · list_presets · save_preset · apply_preset and more — call get_state first; every tool description carries the scene conventions (meters; +X right, −Z forward; heading 0 faces −Z).

A typical agent session: get_state → add_entity/spawn_sequence → apply_camera_move → screenshot to see the result → set_shot/play.

Security

The control server binds to 127.0.0.1 only, uses a per-launch random bearer token, and the app validates every action against a whitelist. Nothing is exposed off-machine.

License & credit

Apache-2.0 — see LICENSE. Per the NOTICE file, use, forks, and redistribution must credit Sam Wasserman (wassermanproductions.com).