ERP MCP Wrapper System

Universal adapter pattern + MCP server for wrapping any ERP into AI-consumable tools

agent-hub/101 2026-04-07 Effort: 18-21 days 6 Adapters ~25-30 Tools

System Overview — Agent → MCP → ERP Flow

One universal MCP server with pluggable adapter backends. Agents never know which ERP they talk to.

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flowchart LR
    subgraph U["  Users  "]
        direction TB
        U1["Employee / Accountant / CEO"]
    end

    subgraph O["  AI Orchestrator  "]
        direction TB
        ORC["LLM Router\nHaiku • Sonnet • Opus"]
    end

    subgraph A["  Agent Layer  "]
        direction TB
        A1["Finance"]
        A2["HR"]
        A3["Supply"]
        A4["Sales"]
        A5["Compliance"]
        A6["Governance Hub"]
    end

    subgraph M["  Universal MCP Server  \n  Streamable HTTP + OAuth 2.1  "]
        direction TB
        REG["Tool Registry\n~25-30 curated tools"]
        WELL["/.well-known/mcp.json"]
    end

    subgraph AD["  Adapter Factory  "]
        direction TB
        AD1["Twendee"]
        AD2["MISA"]
        AD3["SAP"]
        AD4["Odoo"]
        AD5["Google"]
        AD6["Microsoft"]
    end

    subgraph E["  ERP / Digital Office Core  "]
        direction TB
        E1[("PostgreSQL")]
        E2[("MISA Amis")]
        E3[("SAP S/4")]
        E4[("Odoo")]
        E5[("Workspace")]
        E6[("MS 365")]
    end

    U1 --> ORC
    ORC --> A
    A6 -.->|monitor| A1 & A2 & A3 & A4 & A5
    A -->|MCP Protocol| M
    REG --> AD
    AD1 --> E1
    AD2 --> E2
    AD3 --> E3
    AD4 --> E4
    AD5 --> E5
    AD6 --> E6

    style U fill:#1e1b4b,stroke:#6366f1,color:#c7d2fe
    style O fill:#1c1917,stroke:#a16207,color:#fde68a
    style A fill:#052e16,stroke:#16a34a,color:#bbf7d0
    style M fill:#2e1065,stroke:#9333ea,color:#e9d5ff
    style AD fill:#0c1a3d,stroke:#2563eb,color:#bfdbfe
    style E fill:#1a1a1a,stroke:#525252,color:#d4d4d4

Domain Adapter Interfaces — Class Hierarchy

Optional domains via ? — not every ERP supports every domain. MCP only advertises implemented tools.

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classDiagram
    class IERPAdapter {
        <<interface>>
        +hr? IHRAdapter
        +crm? ICRMAdapter
        +finance? IFinanceAdapter
        +supplyChain? ISupplyChainAdapter
        +productivity? IProductivityAdapter
        +authenticate() void
        +healthCheck() HealthStatus
        +getSupportedDomains() string[]
    }
    class IHRAdapter {
        <<interface>>
        +getEmployee(id)
        +searchEmployees(query)
        +createLeaveRequest(data)
        +getAttendance(empId, range)
        +getContracts(empId)
        +getPayrollSummary(empId, month)
    }
    class ICRMAdapter {
        <<interface>>
        +getDeal(id)
        +searchDeals(query)
        +createDeal(data)
        +updateDealStage(id, stage)
        +getLeads(filter)
    }
    class IFinanceAdapter {
        <<interface>>
        +getVoucher(id)
        +createVoucher(data)
        +getFinancialReport(type, range)
    }
    class IProductivityAdapter {
        <<interface>>
        +getEmails(filter)
        +sendEmail(data)
        +getCalendarEvents(range)
        +getDocuments(filter)
    }
    class BaseAdapter {
        <<abstract>>
        #httpClient
        #rateLimiter
        #cache
        +authenticate()
        #refreshToken()
        #withRetry(fn)
        #withCache(key, fn, ttl)
    }
    class TwendeeAdapter { +hr +crm +finance }
    class MISAAdapter { +finance +hr }
    class SAPAdapter { +hr +crm +finance +supplyChain }
    class GoogleAdapter { +productivity }

    IERPAdapter <|.. BaseAdapter
    BaseAdapter <|-- TwendeeAdapter
    BaseAdapter <|-- MISAAdapter
    BaseAdapter <|-- SAPAdapter
    BaseAdapter <|-- GoogleAdapter
    IERPAdapter --> IHRAdapter
    IERPAdapter --> ICRMAdapter
    IERPAdapter --> IFinanceAdapter
    IERPAdapter --> IProductivityAdapter

New ERP Onboarding — Developer Experience

Scaffold → Fill methods → Test → Deploy → Agents auto-discover. Zero agent code changes.

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sequenceDiagram
    actor Dev as Developer
    participant CLI as Scaffold CLI
    participant FS as File System
    participant Tests as Contract Tests
    participant MCP as MCP Server
    participant Agent as AI Agent

    Dev->>CLI: npx erp-mcp scaffold --erp misa --domains hr,finance
    CLI->>FS: Generate adapter stubs
    Note over FS: adapters/misa/
misa-adapter.ts
misa-hr-adapter.ts
misa-finance-adapter.ts
misa-auth.ts • misa-client.ts
__tests__/
    Dev->>FS: Fill in API mapping (~8-10 methods/domain)
    Dev->>Tests: Run contract tests
    Tests-->>Dev: Canonical output shapes verified
    Dev->>MCP: Deploy (restart instance)
    MCP->>MCP: AdapterFactory.getAdapter("misa")
    MCP->>MCP: registerTools(supportedDomains)
    MCP-->>MCP: Emit tools/list_changed
    Agent->>MCP: tools/list
    MCP-->>Agent: hr.getEmployee, finance.getVoucher...
    Note over Agent: Zero changes to
agent prompts!
    Agent->>MCP: hr.getEmployee({ id: "123" })
    MCP-->>Agent: { id, name, email, dept, ... }

Implementation Timeline (18-21 days)

Sequential phases 01-04, then MISA + Productivity adapters in parallel.

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gantt
    dateFormat YYYY-MM-DD
    axisFormat %b %d
    section Foundation
    P01 Canonical Types and Interfaces       :p1, 2026-04-14, 3d
    P02 TwendeeERPAdapter Reference          :p2, after p1, 4d
    section MCP Enhancement
    P03 MCP Server Streamable HTTP           :p3, after p2, 3d
    P04 Scaffold CLI                         :p4, after p3, 2d
    section External Adapters
    P05 MISA Adapter Validation              :p5, after p4, 4d
    P06 Google and Microsoft Adapters        :p6, after p4, 4d

Capability Discovery — Dynamic Tool Registration

MCP server only advertises tools for domains the active adapter implements.

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flowchart LR
    subgraph C["Instance Config"]
        CFG["erpType: misa\ndomains: hr, finance"]
    end
    subgraph F["AdapterFactory"]
        AF["getAdapter(config)"]
    end
    subgraph AD["MISAAdapter"]
        direction TB
        HR["hr: MISAHRAdapter"]
        FIN["finance: MISAFinanceAdapter"]
        CRM["crm: null"]
        SUP["supplyChain: null"]
    end
    subgraph R["MCP Tool Registry"]
        direction TB
        R_HR["hr.getEmployee\nhr.searchEmployees\nhr.createLeave\nhr.getAttendance"]
        R_FIN["finance.getVoucher\nfinance.createVoucher\nfinance.getReport"]
        R_SKIP["crm SKIPPED\nsupply SKIPPED"]
    end

    CFG --> AF
    AF --> HR
    AF --> FIN
    AF --> CRM
    HR --> R_HR
    FIN --> R_FIN
    CRM -.->|not implemented| R_SKIP

    style HR fill:#052e16,stroke:#16a34a,color:#bbf7d0
    style FIN fill:#052e16,stroke:#16a34a,color:#bbf7d0
    style CRM fill:#1c1917,stroke:#525252,color:#a8a29e
    style SUP fill:#1c1917,stroke:#525252,color:#a8a29e
    style R_HR fill:#052e16,stroke:#16a34a,color:#bbf7d0
    style R_FIN fill:#052e16,stroke:#16a34a,color:#bbf7d0
    style R_SKIP fill:#2a1215,stroke:#991b1b,color:#fca5a5

Research Targets — MCP Focus

Prioritized research with assignees, deadlines, and status tracking for each implementation phase.

Critical Pending Phase 01

Canonical Model Extraction

Assignee
Backend Lead
Deadline
2026-04-13 (before Phase 01)
Blocker
Blocks all phases
Output
~30 canonical types + field mapping table
  • Which of 121 Prisma models are business entities vs join tables?
  • Minimal canonical type set agents need (~30 types)
  • Field mapping: Twendee → SAP → MISA → Odoo
  • Zod schema: auto-derive from Prisma or hand-write?
Critical Pending Phase 03

MCP SDK + Streamable HTTP

Assignee
Platform Engineer
Deadline
2026-04-20 (before Phase 03)
Blocker
Blocks MCP server enhancement
Output
NestJS + MCP SDK integration guide
  • @modelcontextprotocol/sdk with NestJS integration
  • OAuth 2.1 PKCE flow for production MCP auth
  • /.well-known/mcp.json endpoint implementation
  • tools/list_changed notification pattern
Critical Pending Phase 03

MCP Client-Side Patterns

Assignee
AI/Agent Engineer
Deadline
2026-04-20 (before Phase 03)
Blocker
Blocks agent ↔ MCP integration
Output
Client integration pattern doc
  • How LLM orchestrator discovers + calls MCP tools
  • Tool filtering per agent role
  • Error handling: MCP error → LLM response
  • Token overhead of 25-30 tool definitions
High Pending Phase 05

MISA API Capabilities

Assignee
Integration Engineer
Deadline
2026-04-28 (before Phase 05)
Blocker
Blocks MISA adapter
Output
API capability matrix + auth flow
  • REST endpoints MISA Amis exposes
  • Auth method: API key, OAuth, session?
  • Rate limits, pagination patterns
  • Vietnamese fields (CMND/CCCD, MST) mapping
Medium Pending Phase 06

Google & Microsoft Graph APIs

Assignee
Integration Engineer
Deadline
2026-04-28 (before Phase 06)
Blocker
Blocks productivity adapters
Output
API mapping + interface split recommendation
  • IProductivityAdapter: separate or sub-domains?
  • OAuth scopes for email, calendar, docs
  • Existing MCP servers to reuse?
  • Batch requests + delta queries
Medium Pending Future (V2)

SAP OData Curation

Assignee
TBD
Deadline
V2 (after MISA validation)
Blocker
No — deferred
Output
SAP endpoint curation guide
  • 5000+ endpoints → ~25-30 curated tools
  • BAPI vs OData: when to use which
  • SAP BTP OAuth 2.0 specifics
  • Existing SAP MCP integrations
ERP MCP Wrapper System · plans/260407-2200-mcp-erp-wrapper-system · Branch: agent-hub/101