ARC-1 — SAP ADT MCP Server

ARC-1 (pronounced arc one [ɑːrk wʌn]) — Enterprise-ready MCP server for SAP ABAP systems. Secure by default, deployable to BTP or on-premise, and hardened with large unit/integration/E2E test coverage.

ARC-1 connects AI assistants (Claude, GitHub Copilot, Copilot Studio, and any MCP client) to SAP systems via the ADT REST API. It ships as an npm package and Docker image.

👁 Test
👁 CodeQL
👁 Dependency Review

Full Documentation | Quickstart | Tool Reference | Blog Series

📖 New: AI ABAP Development blog series — long-form posts on AI for ABAP, ARC-1 design, and real-world BTP / Copilot Studio / Joule walkthroughs. Read the series →

Why ARC-1?

Built for organizations that need AI-assisted SAP development with guardrails. Inspired by the pioneering work of abap-adt-api, mcp-abap-adt, and vibing-steampunk — ARC-1 adds what's needed to run in production:

Security & Admin Controls

• Safe by default — read-only, no free SQL, no table preview, no transport writes, no Git writes. Enable each capability with explicit SAP_ALLOW_* flags

• Action deny list — block specific tool actions with SAP_DENY_ACTIONS (for example SAPWrite.delete), without exposing low-level operation codes to admins

• Package restrictions — limit AI write operations (create, update, delete) to specific packages with wildcards (--allowed-packages "Z*,$TMP"). Read operations are not restricted by package — use SAP's native authorization for read-level access control

• Data access control (off by default) — SAPRead(type=TABLE_CONTENTS) and SAPQuery are gated behind explicit env vars (SAP_ALLOW_DATA_PREVIEW=true, SAP_ALLOW_FREE_SQL=true). These capabilities can expose application data or run ad-hoc SQL, so they are intentionally separated from the default development-tooling surface. They can be enabled for governed use cases, but should be reviewed against the current SAP API Policy, your SAP agreement, and internal data-governance rules

• Transport safety — transport reads are available for review, while transport mutations require both --allow-writes and --allow-transport-writes. Update/delete operations auto-use the lock correction number when no explicit transport is provided

• Git workflow safety — Git operations are disabled by default. Enable explicitly with --allow-git-writes / SAP_ALLOW_GIT_WRITES=true

• API-key profiles — multi-key HTTP deployments can assign viewer, viewer-data, viewer-sql, developer, developer-data, developer-sql, or admin per key

• Writes restricted to $TMP when enabled — only local/throwaway objects; writing to transportable packages requires explicit --allowed-packages

• HTTP security headers (helmet) on by default — HSTS, CSP, X-Frame-Options, CORP, X-Content-Type-Options. COOP is deliberately not set so popup-based OAuth flows (Copilot Studio) keep working. No flag to disable.

• Opt-in CORS for browser MCP clients — ARC1_ALLOWED_ORIGINS (comma-separated, exact match). Off by default; native MCP clients don't need it

• Layered rate limiting — three layers out of the box: per-IP OAuth//mcp edge (Layer 1, default 20/min/IP, on), per-user MCP quota (Layer 2, off by default — multi-user deployments opt in via ARC1_RATE_LIMIT=60), server-wide SAP-bound semaphore (Layer 3, default 10, on). Honors Retry-After on 429/503 from SAP / BTP gateways. Two operator env vars; per-endpoint OAuth ceilings are constants in code. Closes CodeQL alert js/missing-rate-limiting. See the Rate Limiting Guide

• Supply-chain security — Dependabot (npm + GitHub Actions + Docker, weekly + same-day security advisories), npm audit --audit-level=high PR gate, GitHub Dependency Review on every PR, CodeQL SAST, Trivy container scanning (gating on release, advisory on dev), all third-party GitHub Actions pinned to commit SHA, SECURITY.md policy with severity-tiered SLAs. Image and npm package both ship with provenance attestations. See the security guide §13

Authentication

• API key — simple Bearer token for internal deployments

• OIDC / JWT — Entra ID, Keycloak, or any OpenID Connect provider

• OAuth 2.0 — local browser-based login for BTP ABAP Environment service-key development

• XSUAA — SAP BTP native auth with automatic token proxy for MCP clients

• Per-user SAP identity — BTP Destination Service forwards the MCP user to SAP: Cloud Connector principal propagation for on-premise SAP, or OAuth2UserTokenExchange for BTP ABAP Environment

BTP Cloud Foundry Deployment

Deploy ARC-1 as a Cloud Foundry app on SAP BTP with full platform integration:

• Destination Service — connect to SAP systems via managed destinations

• Cloud Connector — reach on-premise systems through the connectivity proxy

• Per-user destinations — user identity forwarded end-to-end via X.509 certificates for on-premise SAP, or exchanged for an ABAP bearer token for BTP ABAP Environment

• XSUAA OAuth proxy — MCP clients authenticate via standard OAuth, ARC-1 handles the BTP token exchange

• Audit logging — structured events to stderr, file, or BTP Audit Log Service

Token Efficiency

• 12 intent-based tools (~5K schema tokens) instead of 200+ individual tools — keeps the LLM's context window small

• Method-level read/edit — read or update a single class method, not the whole source (up to 20x fewer tokens)

• Context compression — SAPContext returns public API contracts of all dependencies in one call (7-30x compression)

Built-in Object Caching

• Server-validated source caching — every SAP object read is cached in memory (stdio) or SQLite (http-streamable). Repeated reads use If-None-Match/ETag conditional GET, so unchanged objects return from cache after SAP confirms 304 Not Modified.

• Dependency graph caching — SAPContext dep resolution keyed by source hash; unchanged objects skip all ADT calls on subsequent runs.

• Pre-warmer — start with ARC1_CACHE_WARMUP=true to pre-index all custom objects at startup, enabling reverse dependency lookup (SAPContext(action="usages")) and fast CDS impact workflows (SAPContext(action="impact", type="DDLS")).

• Active/inactive source views — SAPRead accepts version="active" | "inactive" | "auto" and warns when the active source has an unactivated draft.

• Write invalidation — when SAPWrite or SAPActivate mutates an object, both active and inactive source cache entries are dropped; next read revalidates or fetches fresh source.

See docs/caching.md for full documentation.

Testing

• 3,474 unit tests (104 unit test files, mocked HTTP)

• 262-test default integration profile against live SAP systems, with explicit skip reasons when credentials or fixtures are missing

• 141-test default E2E profile that executes real MCP tool calls against a running ARC-1 server and live SAP system

• Manual slow SAP profiles keep expensive cache warmup, broad where-used, RAP full-stack, and recursive CTS release coverage out of the PR path (test:integration:slow, test:e2e:slow, GitHub SAP Slow Tests workflow)

• CRUD lifecycle and BTP smoke lanes included (test:integration:crud, test:integration:btp:smoke)

• CI matrix on Node 22 and 24; live SAP integration + E2E run on internal PRs and manual dispatch, with SAP jobs gated off for docs/chore PRs and external forks

• Reliability telemetry + coverage published as informational CI signals (non-blocking)

Tools Refined for Real-World Usage

The 12 tools are designed from real LLM interaction feedback:

Tool definitions automatically adapt to the target system (BTP vs on-premise), removing unavailable types and adjusting descriptions so the LLM never attempts unsupported operations.

Feature Detection

ARC-1 probes the SAP system at startup and adapts its behavior:

• Detects HANA, gCTS, abapGit, RAP/CDS, AMDP, UI5, and transport availability

• Auto-detects BTP vs on-premise systems

• Maps SAP_BASIS release to the correct ABAP language version

• Each feature can be forced on/off or left on auto-detect

• In shared-credential mode (technical user), runs a startup auth preflight once and blocks SAP tool calls with a clear error on 401/403 to avoid repeated failed logins and potential user lockout

Related MCP server: SAP ERP MCP Server by CData

ADT API Status and Strategy

SAP's current SAP API Policy is v.4.2026a. It allows published/documented APIs for the purposes described in SAP documentation, while restricting unsupported internal APIs, misuse, unmanaged autonomous AI call patterns, and large-scale extraction outside endorsed paths. ARC-1 is designed as a governed development-tooling proxy around ADT behavior, not as a bulk data-extraction product.

For typical internal developer workflows, ARC-1 should be treated as generally usable when it stays close to documented/discoverable ADT behavior, runs with real user identity, respects SAP authorization, and keeps audit and rate controls in place. Customers should still review their exact landscape, SAP agreement, and AI governance rules, especially when the MCP client can plan or execute sequences of tool calls.

Concretely, ARC-1 is positioned as a custom developer utility for internal development automation: code checks, build/activate, transport management, AI-assisted ABAP authoring, and Git workflows.

Two ARC-1 capabilities can expose business data or execute ad-hoc SQL. Both are off by default and require explicit opt-in env vars, so the operator makes a deliberate decision before they are reachable:

With both flags at their defaults, ARC-1's data/sql rows are unreachable. Turning either flag on is a valid operational choice for approved scenarios, but it should be deliberate: check the current SAP API Policy, the customer's SAP agreement, SAP authorizations, and internal data-protection rules before enabling it on a productive system.

Beyond the policy, the public signals for ADT remain consistent: SAP publishes an ADT SDK, a guide for creating and consuming RESTful APIs in ADT, and has described the ABAP language server direction as an "ADT SDK 2.0".

ARC-1's strategy is to stay close to documented and discoverable ADT behavior, probe system capabilities before exposing tools, keep conservative security defaults (writes off, data preview off, free SQL off, package allowlist $TMP), and continuously review SAP's guidance as it evolves. This README is not a compliance decision for any specific customer landscape, but the default posture is intended to support normal governed development use rather than block it.

Quick Start

npx arc-1@latest --url https://your-sap-host:44300 --user YOUR_USER

• Trying it out on your laptop? → Quickstart

• Full local dev setup (Docker, cookie extractor, client configs)? → Local Development

• Deploying for a team / BTP? → Deployment

Blog Series — AI ABAP Development

A long-form series on blog.zeis.de covering AI for ABAP development, ARC-1's design, and real-world walkthroughs:

1. How I Use AI for Development and Why Context Matters

2. ABAP and Agentic AI: The Hidden Problem in Real Projects

3. Introducing ARC-1: A Secure ADT MCP Server for Enterprise SAP Development

4. ARC-1 on SAP BTP: Secure ABAP Agentic Development Beyond the Laptop

5. ARC-1 with Copilot Studio: SAP System Context Beyond Developers

6. ARC-1 with Joule Studio: Bringing Real ABAP System Context into Joule

7. From SEGW and Legacy UI5 to RAP with ARC-1

Full list and new posts → blog.zeis.de/tags/ai-abap-development-series.

Documentation

Full documentation is available at marianfoo.github.io/arc-1.

Development

npm ci && npm run build && npm test

See CLAUDE.md for codebase structure, testing commands, and contribution guidelines.

Credits

License

MIT

Maintenance

Resources

• NPM Package
• GitHub Repository
Need Help?Related Servers

Tools

• SAPContextA
• SAPDiagnoseA
• SAPLintA
• SAPManageA
• SAPNavigateA
• SAPReadA
• SAPSearchA
• SAPTransportA