REMITT SERVER

REMITT (Electronic Medical Information Translation and Transmission) — Go rewrite of the J2EE 0.5.x SOAP backend, targeting 100% feature parity against the same MySQL schema. Runs against a valid REMITT 0.5.x database with no modifications.

Architecture

Layer	Technology
Language	Go 1.25
Web framework	Echo v5 (migrated from Gin)
ORM	GORP + supplementary sqlc query layer
Database	MySQL (same schema as REMITT 0.5.x — tables, stored procedures, column names are a fixed contract)
Auth	Stateless HTTP BasicAuth (MD5 hashes — legacy 0.5.x compatibility)
Config	YAML (config.yaml)
Plugin model	Registry + factory pattern (init() self-registration)

Plugin Systems (all complete)

Every plugin type follows a uniform registry/factory pattern with init() self-registration:

System	Interface	Implementations	Status
Eligibility	EligibilityChecker	Dummy, Gateway EDI (SOAP+PGP), NC Medicaid (SFTP+PGP), SFTP (optional PGP), Optum (Change Healthcare OAuth2 REST), Stedi (OAuth2 REST), BCBS FHIR (1upHealth), Medicare HETS (CMS SOAP/X12 270/271)	8/8 done
Transport	Transporter	Script (otto JS), SFTP, StoreFile, StoreFilePdf, ClaimLogic, Gateway EDI, ScriptedHttp	7/7 done
Parser	Parser	X12 envelope (ISA/GS/ST/SE/GE/IEA), X12 835 remittance, X12 271 eligibility response, X12 997 functional ack	4/4 done
Translation	Translator	X12Xml (XML→EDI text), X12Passthrough (raw bytes), FixedFormXml (XML→fixed-width), FixedFormPdf (XML→PDF via gofpdf+gofpdi)	4/4 done
Render	Renderer	XsltPlugin (ratago or xsltproc), PreRenderedPlugin (passthrough)	2/2 done
Callback	CallbackSender	SOAP callback to originating systems (WS-Security UsernameToken, fires non-blocking post-pipeline)	1/1 done
Validation	Validator	X12Validator (otto JS engine, scripts in resources/scripts/validation/)	1/1 done
Scooper	Scooper	SftpScooper, GatewayEdiSftpScooper (SFTP + PGP decrypt)	2/2 done

EDI Pipeline

Render → Translation → Transport → Callback

1. Render — produces intermediate output (XSLT transform or passthrough)
2. Translation — resolves format bridge (e.g. X12Xml → X12 EDI text, FixedFormXml → PDF)
3. Transport — delivers the result (SFTP, script, HTTP, local file store)
4. Callback — non-blocking SOAP notification to originating systems with job result

Jobs are dispatched through a channel-based worker pool (jobqueue/). Scheduled tasks (eligibility checks, scooper runs) are driven by task/scheduler.go.

API Endpoints (20/20 complete)

All 20 endpoints from the Java 0.5.x API surface are implemented:

• Authentication & users: changePassword, getCurrentUsername, addRemittUser, listRemittUsers
• Config: getConfigValues, setConfigValue
• Payloads: insertPayload, resubmitPayload, getStatus, getBulkStatus
• Files: getFile, getFileList, getOutputMonths, getOutputYears
• Eligibility: getEligibility, batchEligibilityCheck
• Keyring: addKeyToKeyring
• Plugins: getPlugins, getPluginOptions
• Protocol: getProtocolVersion
• Validation: validatePayload
• Parsing: parseData

Access control is role-based (admin / user) via BasicAuth middleware.

Architectural Changes from REMITT 0.5.x

• Language: Java/J2EE → Go with Echo v5 web framework
• Framework: Apache CXF SOAP → RESTful JSON API + SOAP 1.1 compatibility layer (soap/) for legacy Java clients
• ORM: Hibernate → GORP with supplementary sqlc query layer for type-safe generated queries
• Plugin model: Spring beans → registry/factory pattern with init() self-registration
• Job execution: Thread-per-job → channel-based worker pool (jobqueue/)
• Scheduling: Quartz → lightweight in-process scheduler (task/scheduler.go)
• Auth: Container-managed security → stateless HTTP BasicAuth with MD5 password hashing (legacy DB compatibility)
• Eligibility: Expanded from 4 to 8 checkers — added OAuth2 REST (Optum, Stedi), FHIR R4 (BCBS via 1upHealth), and CMS HETS SOAP/X12 270/271 (Medicare)
• X12: Full envelope + 835/271/997 parsers with 22 DTO structs
• PGP/GPG: Native Go armoring (crypto/pgp.go) — encrypt, decrypt, detect
• Testing: E2E pipeline test suite (test/e2e/) with testdata fixtures + per-plugin unit tests

Dependencies

• Echo v5 — web framework
• GORP — database access layer
• sqlc — type-safe generated queries (internal/db/)
• Go-MySQL-Driver — MySQL driver
• otto — JavaScript engine (script transports, X12 validation)
• goquery — HTML scraping (scripted HTTP transport)
• pkg/sftp — SFTP client
• gofpdf + gofpdi — PDF generation (FixedFormPdf translation)
• ratago — native Go XSLT processor
• gokogiri — native Go XML/DOM/XPath support
• golang-migrate — database migrations
• prometheus/client_golang — metrics instrumentation

Operations

Prometheus Metrics

The server exposes standard HTTP metrics at /metrics in Prometheus text format:

• http_requests_total — counter by method, path, status
• http_request_duration_seconds — histogram by method, path, status
• http_requests_in_flight — gauge of concurrent requests

Docker

docker build -t remitt-server .
docker run -p 3000:3000 -v ./remitt.yml:/etc/remitt/remitt.yml remitt-server

The multi-stage Dockerfile produces a minimal Debian-slim image with xsltproc for external XSLT transforms. All SSH/SFTP connections use Go's golang.org/x/crypto/ssh — no system SSH client required.

Quick Start

cp config.yaml.example config.yaml
# edit config.yaml with your MySQL credentials
go run ./cmd/remitt-server/

The server starts on the port configured in config.yaml (default: 8080).

Code in this repository runs against a valid REMITT 0.5.x series database with no modifications.

Full migration task list: TODO.md