> ## Documentation Index > Fetch the complete documentation index at: https://developers.opencard.io/llms.txt > Use this file to discover all available pages before exploring further. # Overview > Full EMS customer onboarding — billing, TPA, organization, webhook, and card holders — the complete flow from client signup to live transactions. This is the **end-to-end path** for connecting one of your clients to OpenCard. Everything you need lives in the Application API — no embed plugin required. Each major step has its own guide — same pattern as [TPA flow](/ems/tpa-flow) and [Card holders](/ems/card-holders): | Guide | When | | ---------------------------------------------------- | ----------------------------------------------------------------- | | [Payment product setup](/ems/payment-products-setup) | Once per EMS account — enable products before any client onboards | | [TPA flow](/ems/tpa-flow) | Per client — legal authorisation + signatories | | [Card holders](/ems/card-holders) | Per employee — PDPC consent or instant match | | [eID signing](/ems/eid-signing) | Reference for Nordic signing modes | *** ## Who does what | Actor | Role | | ------------- | ----------------------------------------------------------------------------------------------------- | | **Client** | Your end-customer company — signs the TPA; their employees sign PDPC | | **You (EMS)** | Orchestrate setup in your product — call OpenCard APIs, store `reference_id`s, show status in your UI | | **OpenCard** | Legal signing (eID), card issuer communication, webhooks with transactions and enrichment | You own the UX. OpenCard owns signing pages, identity verification, and data delivery. *** ## Big picture ```mermaid theme={null} sequenceDiagram participant Client as Client participant You as You (EMS) participant OC as OpenCard Note over Client,OC: EMS setup (once) You->>OC: GET /payment-products + enable on account Note over Client,OC: Phase 1 — Client setup Client->>You: Choose payment product (marketplace) You->>OC: GET account payment-products (enabled) Client->>You: Choose products + invoice details You->>OC: GET publicrecords (who may sign TPA) Client->>You: Confirm TPA signatories + emails You->>OC: Configure client (billing, TPA, org, webhook) OC->>Client: TPA signing email (eID) Client->>OC: Sign TPA OC->>You: tpa.signed webhook Note over Client,OC: Phase 2 — Cardholder setup Client->>You: Add employee You->>OC: Create Card holder OC->>Client: PDPC email (eID) — Path A Client->>OC: Sign PDPC OC->>You: card_holder.identified Note over Client,OC: Phase 3 — Live OC->>You: Transaction + receipt webhooks You->>Client: Show spend in your EMS UI ``` *** ## Phase 1 — Client setup The client walks through your product: **payment product → add-ons → invoice details → TPA signatories**. You then create billing, TPA, organization, and webhook via the API (or receive the payload from the [ocTPA plugin](/ems/plugins) and POST it yourself). Complete when the TPA is signed (ideally activated), the organization exists with `billing_id` + `tpa_id`, and the webhook is active. → [Payment product setup](/ems/payment-products-setup) · [TPA flow](/ems/tpa-flow) · [Billing](/ems/model/billing) · [Webhooks](/ems/webhooks/setup) *** ## Phase 2 — Cardholder setup Add each employee as a card holder. **Email path** sends PDPC + eID; **instant path** matches on `identity_id` with no user action. Complete when you receive `card_holder.identified` — then expect transactions (including a retroactive batch). → [Card holder onboarding](/ems/card-holders) · [Model: Card holder](/ems/model/card-holder) *** ## Phase 3 — Live Card issuer pushes transaction states → OpenCard POSTs to your webhook → enrichment may follow (receipts, VAT, line items, environmental impact). → [Transaction states](/ems/webhooks/transactions) · [Events](/ems/webhooks/events) · [Receipts](/ems/receipts) *** ## Ordered checklist Do this **per client** (after your account + OAuth client exist): | # | Step | API / action | Detail guide | | - | ------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------- | | 0 | Enable payment product(s) on account (once) | `GET /payment-products` → `POST .../accounts/{id}/payment-products/{id}` (or [application.opencard.io](https://application.opencard.io)) | [Payment product setup](/ems/payment-products-setup) | | 1 | Client picks payment product | `GET .../accounts/{id}/payment-products` → `payment_product_id` on TPA | [Payment product setup](/ems/payment-products-setup) | | 2 | Client picks products | Flags on billing create | [Billing](/ems/model/billing) | | 3 | Invoice email / reference | Part of billing create | [Billing](/ems/model/billing) | | 4 | Create TPA (who signs) | `GET` publicrecords — collect signatories | [TPA flow](/ems/tpa-flow) | | 5 | Configure client | `POST` billings, tpas, signatories, orgs, webhooks | [TPA flow](/ems/tpa-flow) · [Webhooks](/ems/webhooks/setup) | | 6 | Wait for eID + `tpa.signed` | Webhook / status | [eID signing](/ems/eid-signing) | | 7 | Create card holders | `POST` cardholders | [Card holders](/ems/card-holders) | | 8 | Wait for `card_holder.identified` | Webhook | [Card holders](/ems/card-holders) | | 9 | Handle transactions + enrichment | Webhooks | [Transactions](/ems/webhooks/transactions) | *** ## Build it yourself vs embed plugin | Approach | When | | -------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------- | | **API only (this guide)** | Rebuild the same steps in your own UI — recommended for production | | **[ocTPA plugin](/ems/plugins)** | Ready-made wizard: payment product → add-ons → invoice → signatories; **you still POST** billing / TPA / signatories from `onDataSend` | The plugin mirrors Phase 1 in the UI. Organization + webhook and card holders stay in your integration. *** ## Deep dives in this section | Page | What it covers | | ---------------------------------------------------- | ----------------------------------------------------- | | [Payment product setup](/ems/payment-products-setup) | Enable products, marketplace UI, `payment_product_id` | | [TPA flow](/ems/tpa-flow) | Create TPA, signatories, activation, signed PDF | | [eID signing](/ems/eid-signing) | Sign vs auth modes across Nordic countries | | [Card holder onboarding](/ems/card-holders) | Email vs `identity_id`, webhooks, updates | **Models** (what each entity is): [Billing](/ems/model/billing) · [Organization](/ems/model/organization) · [TPA](/ems/model/tpa) · [Card holder](/ems/model/card-holder)