Acme AP is the submitted application: an authenticated buyer portal with 12 browser WebMCP tools for purchase-order context, invoice validation and submission, exceptions, buyer cases, corrected revisions, receipt status, and payment remittance.
Supplier teams normally learn and operate a different portal for every large customer. Direct API integration is a costly project per buyer; manual work is repetitive and error-prone. Acme AP makes the existing portal agent-operable without giving up its authentication, business rules, ledger, or human approval controls.
- Open Acme AP in the ChatGPT desktop app's built-in browser, enable Site tools in Browser permissions, and sign in with the private credentials supplied in Devpost.
- Confirm that the authenticated page exposes exactly 12 tools.
- Ask: “Using only this supplier portal's tools, review its invoice requirements, open purchase orders, current invoices, exceptions, buyer cases, and payment remittance. Explain what the supplier can act on and what Acme owns. Do not make changes.”
- Use the evaluation guide for expected AP behavior. Agents can also read the deployed agent guide.
The Chrome WebMCP flag exposes the experimental page API for lower-level testing. The ChatGPT agent workflow uses the desktop app's built-in browser and Site tools; installing or opening a Chrome side panel alone does not enable Site tools.
Only apps/acme-ap and services/acme constitute the submitted application. Acme AP owns its authentication, authorization, supplier boundary, business rules, database, and ledger. Every AP tool operates only inside that boundary and has a corresponding human UI path.
The repository also contains apps/openfinance-ar, an independently operated synthetic supplier invoice system with its own deployment, authentication, database, and 7 browser tools. AR exists only to make the cross-company demo reproducible. It is not part of Acme AP or its tool count.
WebMCP exposes portal actions as defined capabilities inside the authenticated page. An agent can read Acme's current PO and evidence rules, explain which invoices qualify, submit an approved batch, route exceptions to the recorded owner, and retrieve exact remittance. Acme's backend remains authoritative, and the finance operator controls every document write.
The demonstration uses browser-mediated interoperability rather than a hidden integration. AP and AR share no database, credential, session, server-to-server API, queue, or webhook. The browser agent carries only information the operator approves, and each application writes only its own ledger.
| Area | Impact |
|---|---|
| Portal capabilities | Twelve authenticated tools cover requirements, purchase orders, invoice submission, exceptions, cases, status, and remittance. |
| Operator control | Read and write results appear in the same interface, while document writes require an exact human approval. |
| Supplier workload | An agent can handle buyer-specific rules and exception workflows that finance teams otherwise process portal by portal. |
| System boundary | AP can exchange approved information with an external supplier system without a partner-specific server integration. |
Acme AP runs independently. The repository also includes a separate synthetic AR reference system for reproducing the external-system loop shown in the video.
Opening instruction:
Submit all Acme invoices that can be paid.
Follow-up instruction:
Resolve supplier-owned exceptions, open cases for buyer-owned blockers, and reconcile approved payments back into OpenFinance.
The optional deterministic demonstration finds three external supplier invoices, submits the two that qualify for a total of $25,670 after approval, and leaves one blocked by Acme's current rules. It then resolves a supplier-owned evidence exception, opens a case for a buyer-owned blocker without claiming resolution, and reads exact payment remittance. The AR reference system separately records the AP outcomes. See the evaluation guide for the starting state and visible results.
apps/acme-apandservices/acme: submitted AP product, independent Supabase migrations, reset, and database tests.apps/openfinance-arandservices/openfinance: demo-only AR reference system with a separate Supabase boundary.tests: repository and production-contract tests.docs/openapi.yaml: same-origin HTTP contracts.docs: setup, architecture, security, WebMCP, API, and evaluation guidance.
Requires Bun 1.3.14 or newer.
bun install --frozen-lockfile
bun run typecheck
bun run lint
bun test
bun run buildEach app requires only its own Supabase URL and publishable key. See SETUP.md for migration order, local development, deployment, database tests, and deterministic reset instructions.
MIT. Copyright 2026 Ido Dubovi.