Midnight Toolingproof Server

Midnight Proof Server

The Midnight proof server generates zero-knowledge proofs for Midnight transactions. It can run locally as a Docker container or be accessed as a remote service on testnet/mainnet. The server exposes an HTTP API (default port 6300) that DApps use to request proof generation at runtime.

Local Development

For local development, use the devnet which manages a proof server alongside a node and indexer. Run /midnight-tooling:devnet start to start the full local network. See the devnet skill for details.

The rest of this skill covers working with proof servers directly — useful when connecting to testnet/mainnet or running a standalone instance.

Looking Up Environment Endpoints

Current proof server addresses for testnet and mainnet are published in the Midnight documentation. To look up the latest endpoints:

Use the octocode MCP to fetch the relnotes/overview page from the midnightntwrk/midnight-docs repository:

githubGetFileContent(
  owner: "midnightntwrk",
  repo: "midnight-docs",
  path: "docs/relnotes/overview.mdx",
  fullContent: true
)

This page contains the current network environment details including proof server URLs, node endpoints, and indexer endpoints for all active environments.

Terminology

The proof server is not the same as the Compact compiler. The compiler produces ZK circuits from Compact source code; the proof server uses those circuits to generate proofs at runtime. See the compact-cli skill for compiler installation, compilation commands, and output file details.

Prerequisites

Docker Desktop must be installed and running before the proof server can start.

If Docker is not installed, download it from https://www.docker.com/products/docker-desktop/.

If Docker is installed but not running, start Docker Desktop and wait for it to be ready before proceeding.

Image Version & Tag Selection

The proof server image is published to Docker Hub as midnightntwrk/proof-server with semver-based tags.

Available Tag Types

Listing Available Versions

Fetch available tags from the Docker Hub registry API:

curl -s "https://registry.hub.docker.com/v2/repositories/midnightntwrk/proof-server/tags/?page_size=100&ordering=last_updated" \
  | grep -o '"name": *"[^"]*"' \
  | sed 's/"name": *"//;s/"$//'

Resolving the Latest Stable Version

Filter to tags matching strict semver (X.Y.Z only — no prerelease suffixes, no architecture suffixes), sort numerically, and select the highest:

curl -s "https://registry.hub.docker.com/v2/repositories/midnightntwrk/proof-server/tags/?page_size=100&ordering=last_updated" \
  | grep -o '"name": *"[^"]*"' \
  | sed 's/"name": *"//;s/"$//' \
  | grep -E '^[0-9]+\.[0-9]+\.[0-9]+$' \
  | sort -t. -k1,1n -k2,2n -k3,3n \
  | tail -1

The grep -E '^[0-9]+\.[0-9]+\.[0-9]+$' pattern excludes:

• Prerelease tags (8.0.0-rc.4, 8.0.0-performance.1)
• Architecture-specific tags (7.0.2-arm64, 7.0.2-amd64)
• Non-semver tags (latest)

Version Selection Defaults

Running the Proof Server

The proof server is memory-intensive. Ensure Docker has at least 4 GB RAM allocated. See references/docker-setup.md for resource configuration.

Start the proof server in detached mode so it runs in the background (replace <tag> with the resolved version):

docker run -d --name midnight-proof-server -p 6300:6300 midnightntwrk/proof-server:<tag> -- midnight-proof-server -v

For example, with version 8.0.3:

docker run -d --name midnight-proof-server -p 6300:6300 midnightntwrk/proof-server:8.0.3 -- midnight-proof-server -v

Verifying the Server

After starting, verify the server is healthy:

# Check container is running
docker ps --filter "name=midnight-proof-server" --format "table {{.Names}}\t{{.Status}}\t{{.Ports}}"

# Health check — returns {"status":"ok","timestamp":"..."}
curl -sf http://localhost:6300/health

# Check server version
curl -sf http://localhost:6300/version

# Readiness check — returns {"status":"ok","jobsProcessing":N,"jobsPending":N,"jobCapacity":N,...}
curl -sf http://localhost:6300/ready

# View recent logs
docker logs --tail 20 midnight-proof-server

The server is ready when /health returns {"status":"ok",...} and /ready returns status "ok" with HTTP 200. If /ready returns HTTP 503 with status "busy", the server is running but its job queue is full.

For a one-shot probe of the proof server (and the rest of the devnet) from inside a script, use the midnight-tooling:devnet-health skill — its health.sh calls /version on the proof server with a 5 s timeout.

Stopping the Proof Server

docker stop midnight-proof-server

To remove the stopped container (required before starting a new one with the same name):

docker rm midnight-proof-server

Restarting / Replacing the Proof Server

If a container named midnight-proof-server already exists (running or stopped), remove it before starting a new one:

docker rm -f midnight-proof-server 2>/dev/null
docker run -d --name midnight-proof-server -p 6300:6300 midnightntwrk/proof-server:<tag> -- midnight-proof-server -v

Common Issues

API Endpoints

The proof server exposes the following HTTP endpoints on port 6300:

The /ready endpoint returns HTTP 200 when ready and HTTP 503 when the job queue is full (status "busy").

Reference Files

For local development Docker setup (node, indexer, and proof server together), see the devnet skill and its references/docker-setup.md.

Source: devrelaicom/midnight-expert — distributed by TomeVault.