Tx3 Protocol API Layer

JSON-RPC 2.0 server that dynamically exposes Tx3 protocols. Drop a .tii file into protocols/, restart the server, and the protocol's transactions become available as RPC methods.

Quick start

cargo run

The server listens on http://0.0.0.0:8080 by default.

Configuration

All configuration is read from environment variables at startup.

Variable	Default	Description
PORT	8080	Port the API server listens on.
NETWORK	mainnet	Network / profile name (mainnet, preview, preprod).
PROTOCOLS_DIR	./protocols	Directory scanned for *.tii files at startup.
TRP_URL	(not set)	Override the TRP endpoint (uses Demeter public endpoints by default).
TRP_HEADERS	(not set)	HTTP headers for the TRP endpoint, comma-separated key=value pairs (e.g. dmtr-api-key=mykey). Used when TRP_URL is set.

API Discovery (OpenRPC)

The server implements OpenRPC 1.4.1 for runtime API discovery. The spec is generated dynamically from the loaded .tii files — no manual updates needed.

Endpoint	Description
POST / with method rpc.discover	Returns the full OpenRPC document via JSON-RPC
GET /openrpc.json	Returns the OpenRPC document as plain HTTP
GET /docs	Redirects to the interactive OpenRPC Playground

Discover available methods:

curl http://localhost:8080/openrpc.json

Open interactive docs:

http://localhost:8080/docs

Usage

Methods follow the format <protocol>.<tx>. Parameters are the transaction arguments directly.

Example request:

curl -X POST http://localhost:8080 \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "ticketing-2026.buy_ticket",
    "params": {
      "buyer": "addr1qx2fxv2umyhttkxyxp8x0dlpdt3k6cwng5pxj3jhsydzer3jcu5d8ps7zex2k2xt3uqxgjqnnj83ws8lhrn648jjxtwq2ytjqp"
    }
  }'

Example response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "tx": "84a500818258204dce7e..."
  }
}

Adding protocols

1. Generate a .tii file with trix build.
2. Copy it into the protocols/ directory.
3. Restart the server.

No code changes needed — the server discovers protocols dynamically.

Architecture diagrams

C4 architecture diagrams live in design/001-assets/ as PlantUML sources. To regenerate the SVGs:

docker run --rm \
  -v ./design/001-assets:/data \
  plantuml/plantuml -tsvg /data/c4-context.puml /data/c4-container.puml

See design/001-api-scaffolding-spec.md for the scaffolding specification and design/002-openrpc-discovery-spec.md for the OpenRPC discovery specification.

Development

# Build
cargo build

# Run tests
cargo test

# Run with custom config
NETWORK=preview PORT=3000 cargo run