acumatica-gotchas git:20260901.c608aa5A

Immutable. This exact content never changes and is served at /api/v1/blob/3053d036711edeba.

---
name: acumatica-gotchas
description: >-
  Acumatica ERP integration gotchas, tripwires, and hard-won rules for
  contract-based REST and OData Generic Inquiries (GIs). Use whenever working
  with Acumatica: writing or debugging contract-REST or OData/GIQL calls,
  choosing endpoints or entities, invoking actions (Release, ConfirmShipment,
  FinishCounting), attaching files, or diagnosing symptoms like
  CannotOptimizeException, a write that returns 200 but silently does nothing,
  License_LoginLimitExceeded / session-limit errors, "input parsing" errors,
  empty GI/OData results, or account lockouts. Also use when deciding
  GI-vs-contract-entity or reasoning about auth/session/seat behavior.
---

# Acumatica Integration Gotchas

A portable, cross-repo knowledge base of things that cost real debugging time when
integrating with Acumatica (Construction/Distribution editions, 2023 R1 → 2025 R2)
over **contract-based REST** and **OData Generic Inquiries**. Read the topic file
matching the task; each is a list of atomic entries.

## How to read every entry — the tag legend

Each entry is tagged. **This tagging is the whole point of a cross-repo kit** — it stops
you from carrying one instance's config into another repo as if it were platform truth.

- **`[UNIVERSAL]`** — behavior of the Acumatica platform / API. Holds for any tenant on
  the noted version+edition. Safe to rely on across projects (still confirm the version).
- **`[TENANT]`** — depends on *this instance's* configuration, customization, license, or
  data. **Never copy the value** into another repo — only the *lesson*. (Names, IDs, codes,
  maps, counts, hostnames, endpoint names, GI names, and secrets are always `[TENANT]`.)
- **`[CLAUDE]`** — a tooling note about Claude Code / the Acumatica MCP, not Acumatica itself.

When unsure how to classify something you're adding, read **[reference-vs-tenant.md](./reference-vs-tenant.md)** first.

Entries carry a `Verified:` line (version/edition/date) where known — Acumatica behavior
shifts across releases, so an unverified claim is a hypothesis, not a fact.

## Topics

- **[auth-sessions.md](./auth-sessions.md)** — OAuth 2.0 ROPC, bearer/session/seat behavior,
  the concurrent-login cap, revocation vs logout (and the `Content-Length: 0` / 411 trap that
  makes logout look broken), the connected app as the ONLY tenant binding
  under oauth, seat-neutral session refresh, token/session lifetimes, inactivity
  timeout scope, cookie reuse, account lockout, grant-cache flush.
- **[entities-actions.md](./entities-actions.md)** — per-entity field-name traps, PXAction
  names (Release / ConfirmShipment / FinishCounting), the post-Update-IN CorrectShipment lockout,
  keyed-GET-not-$filter, the file-attach path, long-op polling, PO number padding, drop-ship
  detection, mandatory Project, reason-code usage restrictions.
- **[giql-odata.md](./giql-odata.md)** — CannotOptimizeException, why some reads must ride a GI,
  $select+$expand drops, parameter-free GI requirement, parameterized-GI-empty-over-OData and the
  `_WithParameters` FunctionImport that does bind them, calculated-column filters returning an
  empty-body 200, display-name-derived property naming vs undocumented column order, MCP column
  renames, @odata.nextLink paging, empty-result cache poisoning.
- **[writes-idempotency.md](./writes-idempotency.md)** — the silent-200-on-revoked-write trap,
  endpoint detail collection-vs-object mapping, idempotency, operator attribution, money precision.
- **[reference-vs-tenant.md](./reference-vs-tenant.md)** — the classification rule + a checklist
  of what is ALWAYS tenant-specific. Read this before adding an entry or porting a fact.

## Adding a learning

Run **`/acumatica-learn`** and describe the lesson — it appends a correctly-tagged, version-stamped
entry to the right topic file. See [CONTRIBUTING.md](../../../../CONTRIBUTING.md) for the entry
template and maintenance cadence.