Erp Report Engine MCP Server

erp-report-engine

The numbers for Monday's meeting are already sitting in your ERP's database. So who's still writing the report?

A read-only, self-verifying data layer for the SQL database behind your ERP — weekly reports and a guarded MCP server for AI agents. Every query provably read-only: measured against 28 attacks, not promised in prose.

🇹🇷 Türkçesi: README.tr.md

One scheduled run executes 9 audited SELECT statements and delivers a self-contained HTML report: four KPIs against an 8-week baseline, findings with named drivers, a data-quality gate, and row counts reconciled against the source. No BI license, no agent installed on the ERP server, and no writes — enforced in four layers (lexical, parse-tree, a side-effecting-function guard, and a read-only session), not promised in prose.

This exact report was produced by one command against the bundled demo database — including the three data-quality problems deliberately seeded into it, all caught by the gate.

The same guarded engine talks to AI agents, too. erp-report-engine mcp exposes the ERP to an agent through canonical entities (orders, never LG_001_01_ORFICHE) behind the same read-only guard — the layer the MCP ecosystem keeps getting wrong. The reference PostgreSQL MCP server's read-only mode was walked out of with COMMIT; DROP SCHEMA public CASCADE; and archived; Supabase's MCP became the textbook "lethal trifecta". Here the guard checks the functions a statement calls, not just its shape — and you don't have to take the adjective's word for it:

▶ Run the 28-attack trust benchmark · break the guard yourself, in your browser (the real guard.py, via Pyodide, nothing sent anywhere).

The exact guard.py the tests run, executing in the browser — a file read and the read-only-transaction escape refused, a real aggregate allowed. Paste your own attack →

60-second demo (no ERP required)

# install (pipx or uv keep it isolated; plain pip works too)
pipx install erp-report-engine          # or: uv tool install erp-report-engine
# from source instead:  pip install .

erp-report-engine init-demo             # builds demo.db + config.demo.yaml here
erp-report-engine run -c config.demo.yaml

Every command is also available as python -m erp_report_engine …. Add a database driver with the extras: pipx install "erp-report-engine[mssql]" (Logo Tiger / Netsis / Mikro — SQL Server) or [postgres].

Prefer Docker? docker build -t erp-report-engine . then docker run --rm -v "$PWD:/work" erp-report-engine run -c config.demo.yaml. SQLite and PostgreSQL work out of the box; for MSSQL add Microsoft's ODBC driver (see the Dockerfile). Publishing to PyPI is a GitHub Release away — publish.yml builds and uploads via Trusted Publishing (OIDC, no stored token), and CI already builds the wheel and asserts every bundled profile ships.

Open reports/erp_report_<week>.html. You'll see the engine catch a revenue spike and attribute it to one region, flag a two-point on-time decline, list items below two weeks of stock cover — and confess every duplicate and negative row it found on the way.

▶ See a live sample report: gulmezeren2-byte.github.io/erp-report-engine (also committed at docs/sample-report.html).

Or run run --dashboard for the premium Command Center — a dark, modern, self-contained dashboard with animated KPIs and glowing SPC control-band charts (live):

What one run produces

How it works

flowchart LR
    DB[("ERP database<br/>MSSQL · PostgreSQL · SQLite")]
    PROF["Semantic profile<br/>(YAML contract)"]
    GUARD["safe_read<br/>read-only guard + audit"]
    GATE["Data-quality gate<br/>+ source reconciliation"]
    KPI["KPI engine<br/>ISO weeks, 8-wk baseline"]
    INS["Insight rules<br/>driver attribution"]
    HTML["Self-contained<br/>HTML report"]
    STATE[("state.db<br/>run memory")]

    PROF --> GUARD
    DB --> GUARD --> GATE --> KPI --> INS --> HTML
    STATE --- HTML
    GATE --> PBI["Power BI Command Center<br/>(TMDL + PBIR, code-authored)"]

The layer that makes this portable is the semantic profile: a versioned YAML contract that maps one ERP's cryptic schema to three canonical entities — orders, order_lines, inventory — plus an optional receivables entity (open AR, for aging) that a profile maps when the ledger is reachable and everything downstream skips gracefully when it isn't. The engine only ever sees canonical columns. Swap the profile, keep the report.

The security model

Pointing software at a production ERP database is a trust decision. This engine treats it that way — the guarantees are enforced in code and covered by tests:

Read-only is enforced in four layers, so no single mistake makes the engine capable of writing:

Ad-hoc SQL — the agent path — is stricter still. query and guarded_query run in strict mode, which default-denies every function the guard cannot name: sqlglot's function registry is the allowlist, since it knows the portable analytic functions and nothing that reads a file or opens a socket. All four bundled profiles pass it — they call no unrecognised function at all.

And the layer that isn't ours. MSSQL has no session-level read-only switch, so run the engine under a least-privilege, read-only login (db_datareader on MSSQL, a SELECT-only grant on PostgreSQL — ideally a read replica). The guard is defence in depth; the grant is the layer that holds if the guard has a hole. It has had one before: these function bypasses were found by auditing this repo, and are now pinned in tests/test_guard.py by name, per dialect.

Don't take my word for it — measure it. The guard ships with a reproducible trust benchmark: 28 well-formed-SQL attacks across four dialects that a shape-only guard waves through, every one refused, plus the legitimate reads that must still pass. The number is computed from a live guard run, not asserted in prose, and CI enforces it on every commit.

And "28/28" only means something next to what a weaker guard scores on the same 28. So the benchmark runs the corpus through the shortcuts real tools actually ship — a starts-with-SELECT head check and a write-keyword blocklist — and shows the gap: they refuse 6 and 9 of the 28, and the keyword scan even blocks a legitimate read whose text contains the word "delete", while this guard refuses all 28 and blocks none. A test pins that it strictly beats every such shortcut.

erp-report-engine trust-benchmark
#   this guard               28/28 attacks refused · 8/8 reads allowed
#   starts-with-SELECT        6/28                  · 8/8   (waves 22 through)
#   write-keyword blocklist   9/28                  · 7/8   (leaky AND breaks a real read)

▶ See the results: the trust benchmark — every case, its severity, and what it actually does. Or break it yourself: paste SQL into the real guard, running in your browser (no install, nothing sent anywhere — it's the exact guard.py the tests run, via Pyodide).

Further reading: why "read-only-in-prose" is not read-only (the two famous MCP database failures and the class of attack behind them) · read-only database access for AI agents, compared (transactions vs roles vs statement guards vs semantic layers — honest about where each wins).

Plus: profile variables are identifier-safe (^[A-Za-z0-9_]{1,16}$, so "001; DROP TABLE x" raises before any connection), secrets never live in config files (the loader refuses embedded credentials in any spelling — password, passwd, pwd, sslpassword, ODBC PWD= — use url_env), every executed statement ships in the report's audit trail, and a row cap (default 500k) bounds any single query.

The test suite throws a battery of injection attempts at the guard — multi-statement, comment smuggling in three syntaxes, transaction-control splices (ROLLBACK/COMMIT), SELECT INTO, lock hints, and a DELETE hidden inside a CTE — and expects every one to raise. See SECURITY.md.

Connect your own ERP

1. Put the connection URL in an environment variable (never in the file):

# Windows (System Properties → Environment Variables, or:)
setx ERP_DB_URL "mssql+pyodbc://readonly_user:***@SERVER/LOGODB?driver=ODBC+Driver+17+for+SQL+Server"

1. Copy config.example.yaml → config.yaml:

connection:
  url_env: ERP_DB_URL          # the engine reads the URL from this env var
profile: logo_tiger            # a bundled profile name, or a path to your own YAML
profile_vars:
  firm_no: "001"               # identifier-safe values only, validated
  period_no: "01"
report:
  company_alias: "Company"     # display name — use an alias if you prefer
  lookback_weeks: 13
  low_cover_weeks: 2.0
limits:
  row_cap: 500000
  query_timeout_s: 60

1. Dry-run it — validate connects, checks the profile contract and reconciles counts, touches nothing else:

python -m erp_report_engine validate -c config.yaml
python -m erp_report_engine run -c config.yaml

Included profiles

Profiles ship inside the package and are referenced by name (generic, logo_tiger) — no profiles/ folder needs to exist next to your config.

• generic — the canonical schema; also the template for writing your own.
• logo_tiger — Logo Tiger / GO on MSSQL: LG_{firm}_{period}_ORFICHE order headers joined to CLCARD customers, ORFLINE lines, STINVTOT stock totals, TRCODE = 2 sales filter, and optional receivables aging from PAYTRANS (installment TOTAL − PAID, MODULENR = 4). Logo schemas vary by release — the profile carries field notes on exactly what to verify against your version before trusting it.
• netsis — Logo Netsis 3 on MSSQL (database-per-company): TBLSIPAMAS/TBLSIPATRA sales orders (FTIRSIP = '6'), TBLCASABIT customers, TBLSTOKPH stock totals, and optional receivables aging from TBLCAHAR (with the open-item vs. running-balance caveat called out inline — the honest weak point). Field-mapped from real production integrations, with the weak points (order status, delivery dates, AR closing method) flagged inline to verify against your install.
• mikro — Mikro ERP (Mikro Yazılım, Fly/Jump/V16–V17) on MSSQL: SIPARISLER (sip_ prefix, line-level) sales orders, CARI_HESAPLAR customers, STOK_HAREKETLERI on-hand (sth_tip in/out), and optional receivables aging from CARI_HESAP_HAREKETLERI (cha_vade due date). The honest weak points — the sip_tip sales filter, VAT-inclusiveness of the total, no ship date on the order, and a pure running-balance AR ledger with no open-item flag — are flagged inline to verify against your version.

Together, Logo Tiger, Netsis, and Mikro cover most of the Turkish SME ERP market (all MSSQL). Writing a profile for another ERP (SAP B1, Odoo, a custom system) means writing three SELECT statements that output the canonical columns — either a standalone YAML you point profile: at, or a file dropped into erp_report_engine/profiles/ to ship it bundled. That's the whole contract — and validate tells you immediately whether you got it right.

Make it autonomous

The engine is a single idempotent command, so any scheduler works:

# Windows Task Scheduler — every Monday 07:00
schtasks /create /tn "erp-weekly-report" /sc weekly /d MON /st 07:00 ^
  /tr "cmd /c cd /d C:\erp-report-engine && python -m erp_report_engine run -c config.yaml"

# cron — every Monday 07:00
0 7 * * 1  cd /opt/erp-report-engine && python -m erp_report_engine run -c config.yaml

Each run appends to state.db, which is how the report can say "third consecutive weekly decline" — memory across runs, without re-querying history from the ERP.

Exit codes let the scheduler branch on why a run failed: 0 success · 2 config error · 3 database/connection error · 4 contract error (profile schema wrong or source counts don't reconcile) · 5 data-quality failure under --strict · 1 anything unexpected. The machine-readable result goes to stdout (… run -c config.yaml | jq); logs go to stderr, optionally also to a JSON-lines file with --log-file run.jsonl. Run validate --strict in CI to fail the pipeline when the numbers don't reconcile.

An optional AI summary that can't lie. run --narrate adds an LLM executive summary — but honest by construction: the model is fed only the audited aggregates (KPIs, findings, aging/concentration — never a raw row), and the report prints the exact payload it saw, so anyone can verify what it was given. No key configured → the flag no-ops and the report is unchanged. Any OpenAI-compatible endpoint works, including a local, keyless model (Ollama / LM Studio). Most tools bolt on hallucination checks after generation; here the model simply never sees anything it could leak or over-claim from.

Delivery is built in. run --send emails the report (SMTP), posts a summary to Slack or Teams (Power Automate Workflows), and pings a healthchecks.io dead-man's-switch on success or failure — so a silent cron is detectable. Every secret comes from an environment variable; a channel that fails is logged, never fatal. Configure it in a delivery: block (see config.example.yaml). For a full hands-off pipeline, the power_automate channel posts an Adaptive Card to Teams and archives the HTML report to SharePoint/OneDrive — an importable flow and step-by-step guide live in automation/POWER-AUTOMATE.md. The report writes itself and delivers itself — the feature most BI tools charge for.

The Power BI Command Center

The engine also feeds an interactive Power BI layer — and there is no .pbix binary in this repo. The entire artifact is a PBIP project authored as code: the semantic model in TMDL (star schema, 28 documented DAX measures — including SVG micro-chart measures that draw a per-customer sparkline and a per-item cover bar straight from DAX, and a receivables-aging fact + measures — a Time Shift calculation group on a gapless week ordinal, and a field parameter), the report in PBIR (5 pages / 30 visuals, generated from compact specs by a script), and a dark futuristic theme validated against Microsoft's official theme schema.

# a demo export already ships in powerbi/data — just open the project:
#   powerbi/ERP Command Center.pbip   (Power BI Desktop)
# to feed it your own ERP (writes to gitignored powerbi/data.local by default):
erp-report-engine export-powerbi -c config.yaml

The signature is the Trust page: source reconciliation, the data-quality gate and the full SQL audit trail rendered as visuals — the dashboard shows its receipts. Alert thresholds are the same ones as insights.py, re-derived in DAX: one definition, two surfaces. Field bindings are validated against the TMDL model by pbir-cli before the project ever meets Desktop. Full guide: powerbi/README.md.

Ask your ERP through an agent — the guarded MCP server

An AI agent connecting to an ERP is a trust problem nobody has solved well: every existing "ERP MCP" is a REST wrapper that leans on the ERP's own permissions, and every database MCP hands the agent raw tables. This engine ships the combination that doesn't exist elsewhere — a Model Context Protocol server where the agent talks to canonical entities (orders, never LG_001_01_ORFICHE), through the same read-only guard and audit trail as the report — in strict mode, which default-denies every function the guard cannot name, with every data result framed as untrusted input.

pipx install "erp-report-engine[mcp]"
erp-report-engine mcp -c config.yaml          # stdio server

Six tools, all funneled through the guarded path:

The canonical model is also published as a machine-readable contract — model.json, or erp-report-engine schema — so a tool can read the entities, column types, meanings, and example queries without connecting. CI regenerates it from the code and fails on drift, so the contract can't say more than the engine holds.

A first-party agent skill pack (erp-safe-query, explain-kpi-move, write-erp-profile) teaches an agent to work with this grain — dry-run before querying, aggregate instead of dumping rows, cite audited numbers, and never treat ERP text as a command.

Point Claude Desktop (or any MCP client) at it:

{ "mcpServers": { "erp": { "command": "erp-report-engine", "args": ["mcp", "-c", "C:\\path\\config.yaml"] } } }

Or install it as a Claude Code plugin — the guarded MCP server, the safe-query skills, and zero-setup /trust-benchmark and /erp-schema commands, in two lines:

/plugin marketplace add gulmezeren2-byte/erp-report-engine
/plugin install erp-report-engine

The server launches via uvx (no manual install), reading erp-config.yaml from your project. The skills and the benchmark/schema commands work immediately, before you wire a database. (Details: .claude-plugin/.)

The agent cannot write: the guard rejects anything but a single read query calling only functions it recognises, the session is read-only, and — per the 2025 MCP data-exfiltration incidents — every returned value carries a note that rows are data, not instructions. It is, as far as we can find, the first SQL-level-guarded ERP MCP server, and the first for Logo Tiger.

What this does NOT do

Honesty over marketing — you should know the edges before pointing it at production:

• On-time here is OTIF-lite. It scores order-level shipped ≤ promised. True OTIF needs line-level receipt data most ERP order tables don't carry — so the report says "on-time shipping", not "OTIF", and the footer says why.
• On-time only scores orders that shipped — and that direction is dangerous. An order that is late and still unshipped has no actual_ship_date, so it is in neither the numerator nor the denominator, and never costs the metric a point. Taken to its end, on-time % rises as fulfilment collapses: the worst orders leave the sample. The engine cannot fix that with the data an order table carries, so it counts what the percentage can't see — "N orders were promised this week and have not shipped" — on the card and as its own finding. Read the two together or don't read the percentage.
• On-time moves are not called on thin samples. Two deliveries going 1-of-2 to 2-of-2 is "+50 points", and reporting that with a straight face is how a report loses the room. Below five scored deliveries the move is shown and explicitly not called.
• Findings are pointers, not verdicts. "Driver: region Ege, 111% of the move" tells you where to look first. It does not tell you why — that's the analyst's job (yours).
• The Logo Tiger profile is a field mapping, not a certified integration. Logo schemas differ by version and localization; the profile's field notes list what to verify.
• The current partial week is never plotted. Trends end at the last completed ISO week, because a Monday-morning "crash" that's really a two-day week is how dashboards lose trust.
• It's a weekly briefing, not a BI platform. No drill-down, no real-time, no user management. It does one job: the Monday report writes itself, with receipts.

Design decisions

Why rule-based findings instead of an LLM? Determinism. The same database state always produces the same report, it runs air-gapped next to the ERP, and a number in the report can always be traced to a SQL statement in the audit trail. Nothing is generated that can't be re-derived.

Why a self-contained HTML file? Zero infrastructure. Inline SVG charts, inline CSS, no CDN, no tracking — it renders in Outlook's browser preview, on a phone, from a file share, ten years from now.

Why reconcile row counts? Because "the DataFrame has 494 rows" and "the source query returns 494 rows" are different claims. An unattended system must audit its own inputs — every entity is re-counted with an independent COUNT(*) and any mismatch is flagged in red before anyone trusts a KPI.

Tests

pip install pytest && python -m pytest tests/ -v

The suite covers the read-only guard (a battery of injection attempts), profile contracts, the calendar core (unit + property-based), render escaping, the honesty fixes, CLI exit codes, the MCP tools, SPC signals, delivery routing, and a full end-to-end run plus Power BI PBIP integrity (exporter keys, gapless week ordinals, visual-overlap detection, every visual field exists in the model). CI additionally runs ruff and fails on PBIR generator drift, on Python 3.10–3.13.

Roadmap

Shipped: the guarded MCP server + a first-party agent skill pack, an optional LLM narrative layer (aggregates-only, honest by construction), the SPC/XmR anomaly layer, native delivery (SMTP/Slack/Teams/healthchecks) + a Power Automate pipeline, declarative profile contracts, three real Turkish-ERP profiles (Logo Tiger, Netsis, Mikro) — each with optional receivables aging (cari yaşlandırma) — revenue-concentration analysis (top-3 share + HHI), DAX SVG micro-charts, and a schema-validated dark Power BI theme. Next:

• pip install erp-report-engine on PyPI + a Docker image
• More ERP profiles (SAP Business One, Odoo, a generic ODBC template)
• Exact FIFO open-item aging for the running-balance ledgers (Netsis / Mikro), so receivables aging is precise without open-item matching configured

Part of the measurement-honesty series

Tools that tell you the truth about your operation, by Eren Gülmez:

• otif-analytics — the 5-step metric ladder from "98% reported" to "59% OTIF"
• forecast-accuracy-lab — WMAPE vs MAPE, and why zero-dropping flatters your forecast
• opsaudit — ops metrics CLI with a non-removable honesty block
• auto-report-pipeline — this engine's CSV-fed little sibling
• forecast-autoresearch — an agent improving a forecast against a sealed holdout

License

MIT © Eren Gülmez