NFC Tap Builder by Tap.Giving

NFC Tap Builder by Tap.Giving

Welcome. This is the public home of Tap.Giving's MCP server, "NFC TapBuilder by Tap.Giving". A design tool first: this server helps you create print-ready NFC tap artwork proofs. Work from its published spec and design directions, compose the artwork with your own tools, and submit the finished file to see it on the disc as a proof. The artwork is yours: print-ready, vendor-neutral, yours to take to any printer. Ordering discs through Tap.Giving is an optional next step, only if you want it. The discs it designs for are customNFC tap discs, tap plates, and tap tags. No subscriptions and noongoing fees: one-time pricing per order, and the Redirect Dashboardis included free, permanently.

• Website: https://tap.giving
• Endpoint: POST https://tap.giving/mcp (MCP over StreamableHTTP, JSON-RPC 2.0, stateless). GET https://tap.giving/mcpreturns a short self-description for people and agents.
• Agent index: https://tap.giving/llms.txt,the site's llms.txt, names this server and links back to this repo.
• Spec: the published design and tool contracts live indocs/spec.md. The server is built and accepted:every acceptance leg passed, including the field-for-field invoiceparity check against Stripe test mode on 2026-11-07.
• This repo stays clean: README, the published spec, and thereleased server code. Working notes and anything touching privatebusiness operations live elsewhere by design.

Connect

Paste-ready client config. The keyless read side works exactly asshown, with no auth header:

{
  "mcpServers": {
    "tap-giving": {
      "type": "http",
      "url": "https://tap.giving/mcp"
    }
  }
}

Placing an order needs no key and no header. To present a key forthe organization-bound surfaces (order status, webhook registration,and the order questions' organization block), add it as a header onthe same block:

{
  "mcpServers": {
    "tap-giving": {
      "type": "http",
      "url": "https://tap.giving/mcp",
      "headers": { "Authorization": "Bearer <key>" }
    }
  }
}

Claude Code, one line:

claude mcp add --transport http tap-giving https://tap.giving/mcp

Discovery, product facts, the artwork spec, and theorder questions need no key; exact totals come from get_quote at theend. Placing an order needs no key either; order status and webhookregistration are the surfaces that use one. The live GET https://tap.giving/mcp self-descriptioncarries this same connect guidance.

What the server does

A design tool first: this server helps you create print-ready NFC tap artwork proofs. Work from its published spec and design directions, compose the artwork with your own tools, and submit the finished file to see it on the disc as a proof. The artwork is yours: print-ready, vendor-neutral, yours to take to any printer. Ordering discs through Tap.Giving is an optional next step, only if you want it.

The discs themselves are custom NFC tap discs, tap plates, and taptags for organizations of every kind: built for churches, nonprofits, restaurants, coffee shops, and local businesses,designed by your own agent.

The read side is open and needs no key: an agent can discover theproduct, see the per-disc price range, read the artwork spec with houseexample designs, and submit artwork for validation before any contactexists. Exact pricing is quoted only at the quote step. Placing anorder needs no key; order status is the read that uses one (see below).

This server moves no money itself and issues no invoices:a person from Tap.Giving follows up with the invoice. Payment, design approval, and production releasestay human gates: no tool takes payment, approves a design, orreleases an order to production.

Tools

Annotations are the server's own declarations, read from the livetools/list: every tool also declares destructiveHint: false andopenWorldHint: false. A client can auto-approve the read-onlytools, ask its person before the writes, and retry create_orderafter a network failure with the same idempotency key.

Worked example

One full pass through the journey, captured from the live server on2026-11-07 with test organizations, in test mode throughout (theorders and invoice below are test records). Every field name andvalue shown is exactly what the server returned; long values areshortened only where marked. Each result returns both thestructured content and a plain-text rendering, and both are shown.

1. get_discovery (no key)

Request:

{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": "get_discovery", "arguments": {}}}

Response, structured content (abbreviated):

{
  "server": {
    "name": "NFC Tap Builder by Tap.Giving",
    "endpoint": "https://tap.giving/mcp",
    "synonyms": [
      "tap discs",
      "tap plates",
      "tap tags",
      "NFC tap discs"
    ]
  },
  "introduction": {
    "builder": "NFC Tap Builder by Tap.Giving",
    "positioning": "A design tool first: this server helps you create print-ready NFC tap artwork proofs. Work from its published spec and design directions, compose the artwork with your own tools, and submit the finished file to see it on the disc as a proof. The artwork is yours: print-ready, vendor-neutral, yours to take to any printer. Ordering discs through Tap.Giving is an optional next step, only if you want it.",
    "product": "A tap disc is a small physical disc a phone taps to open your page instantly. It carries a locked tap chip. It comes in one standardized 4-inch size (100 mm), in two shapes, and it is durable waterproof PVC.",
    "firstChoice": {
      "field": "shape",
      "options": [
        "round",
        "square"
      ]
    }
  },
  "journey": [
    {
      "step": "artwork spec",
      "tool": "get_artwork_spec",
      "detail": "The production geometry and the house design directions for the chosen shape."
    },
    {
      "step": "build the artwork",
      "tool": "get_artwork_spec",
      "detail": "Compose the artwork from a design direction with your own tools."
    },
    {
      "step": "submit and proof",
      "tool": "submit_artwork",
      "detail": "Submit the finished file and see it on the disc as a proof. The artwork is yours to take to any printer."
    },
    {
      "step": "order, optional",
      "tool": "get_quote",
      "detail": "Only if you want discs from Tap.Giving: the binding quote at an exact quantity, then the order questions, order setup, and the hosted invoice."
    }
  ],
  "pricing": {
    "range": "Price range of $3.50 - $5.00 per disc depending on quantity.",
    "shipping": "Free on every order.",
    "note": "Call get_quote for the binding quote at an exact quantity."
  },
  "artworkSpec": {
    "summary": "106 mm (about 4.2 inch) square artboard; 100 mm (4 inch) cut (round or square); 3 mm (about 0.12 inch) bleed; vector artwork back (SVG preferred).",
    "tool": "get_artwork_spec"
  },
  "photos": [
    {
      "id": "phone-tap",
      "alt": "A phone tapping a Tap.Giving disc on a chair back, opening the organization's page",
      "mimeType": "image/webp",
      "displayUrl": "https://tap.giving/mcp/photos/phone-tap.webp"
    }
  ],
  "capabilities": {
    "readTools": [
      "get_discovery",
      "get_quote",
      "get_product",
      "get_artwork_spec",
      "get_order_questions",
      "get_recap"
    ],
    "keyedReadTools": [
      "get_order_status"
    ],
    "writeTools": [
      "submit_artwork",
      "start_order_intent",
      "create_order",
      "register_webhook"
    ],
    "gates": [
      "Design approval stays human: a person approves the final proof by email before production. No tool on this server records or implies an approval.",
      "Payment stays human: This server moves no money itself and issues no invoices: a person from Tap.Giving follows up with the invoice. A person pays the invoice when it arrives.",
      "Production release and the supplier handoff stay human: no tool on this server releases an order to production or touches fulfillment state."
    ],
    "howToGetAKey": "Placing an order never requires a key: discovery, product facts, the artwork spec, the order questions, the recap, and order setup all run keyless. An organization API key is optional: it enriches the order questions with the key's own organization block, and it governs order status and webhook registration. Keys are issued by the Tap.Giving team: email [email protected] from the address you want associated with the organization, say which organization the key is for, and the team replies with the key within one business day. Keys look like tg_live_<orgslug>_<secret>; test keys look like tg_test_<orgslug>_<secret>.",
    "kickoff": "get_artwork_spec",
    "benefits": [
      "Works with any platform",
      "No subscription fees",
      "Durable waterproof PVC with a locked tap chip",
      "Custom branding on every design",
      "Free shipping",
      "Covered by our 30-day money-back guarantee"
    ],
    "guarantee": "Covered by our 30-day money-back guarantee."
  }
}

Response, text rendering (complete):

NFC Tap Builder by Tap.Giving
A design tool first: this server helps you create print-ready NFC tap artwork proofs. Work from its published spec and design directions, compose the artwork with your own tools, and submit the finished file to see it on the disc as a proof. The artwork is yours: print-ready, vendor-neutral, yours to take to any printer. Ordering discs through Tap.Giving is an optional next step, only if you want it.

What it is
A tap disc is a small physical disc a phone taps to open your page instantly. It carries a locked tap chip. It comes in one standardized 4-inch size (100 mm), in two shapes, and it is durable waterproof PVC.
The discs themselves are for organizations of every kind, designed by your own agent.
Every disc carries its own Tap.Giving address, so where a tap lands is set per disc. An order starts with one destination for the whole set, the page you give at order setup. To run two destinations, for example counter discs opening your menu and door discs opening your review profile, split the set afterwards in the free Redirect Dashboard: re-point any single disc, or any group of discs, in seconds, and re-point them again anytime. Your dashboard sign-in works from order setup: the address is go.tap.giving/<your-organization-slug>, the username is that slug, and the password arrives by email with the shipping notice, before your discs arrive. Tapping needs no app: iPhone XS (2018) and later and most Android phones from about 2015 read the disc automatically in the background. Where a design carries a printed QR code (your artwork includes one, or the Tap.Giving address line on the design), a phone without NFC, or with NFC off, scans that code and lands on the same destination; a design with no printed code has the tap as its only door, and the design choice is yours at artwork time.

How it works: the design path first
1. Start with the shape, round or square.
2. Get the artwork spec and the design directions for that shape from get_artwork_spec.
3. Build the artwork from a direction with your own tools, adding the organization's logo or name.
4. Submit the finished file with submit_artwork and see it on the disc as a proof. The artwork is yours from here: take it to any printer, or order the discs from Tap.Giving.
5. Optional, only if you want the discs made: get the binding quote from get_quote, answer the order questions, and set the order up. The final proof is emailed for a person's approval before anything is printed, and a person pays the hosted invoice.

Why Tap.Giving
No subscriptions and no ongoing fees: one-time pricing per order, and the Redirect Dashboard is included free, permanently.
- Works with any platform
- No subscription fees
- Durable waterproof PVC with a locked tap chip
- Custom branding on every design
- Free shipping
- Covered by our 30-day money-back guarantee

Pricing
Price range of $3.50 - $5.00 per disc depending on quantity. Free shipping. Tax, where it applies, is calculated on the invoice. Every order is covered by our 30-day money-back guarantee. Production and delivery run 2 to 3 weeks from artwork approval.

Gates
Design approval, payment, and production release stay human: a person approves the final proof by email. This server moves no money itself and issues no invoices: a person from Tap.Giving follows up with the invoice.
Placing an order needs no key: the whole placement run is keyless (the order questions, the recap, and placing the order), and a person from Tap.Giving follows up with the invoice. Order status is the one read that uses the organization key. Placing an order never requires a key: discovery, product facts, the artwork spec, the order questions, the recap, order setup, and the invoice link all run keyless. An organization API key is optional: it enriches the order questions with the key's own organization block, and it governs order status and webhook registration. Keys are issued by the Tap.Giving team: email [email protected] from the address you want associated with the organization, say which organization the key is for, and the team replies with the key within one business day. Keys look like tg_live_<orgslug>_<secret>; test keys look like tg_test_<orgslug>_<secret>. Evaluating the server? A test key runs the full journey, including placing a test order, with no real order and no charge. There is no self-serve signup: email [email protected] and ask for a test key, and the team replies with one (a tg_test_<orgslug>_<secret> key) within one business day.
The photo with this answer shows the disc in use: a phone tapping a disc on a chair back. The structured photos list the labeled photo set from the website library.

2. get_quote at 250 (no key)

Request:

{"jsonrpc": "2.0", "id": 2, "method": "tools/call", "params": {"name": "get_quote", "arguments": {"quantity": 250}}}

Response, structured content:

{
  "quantity": 250,
  "tier": "200-399 discs",
  "unitCents": 400,
  "discUnitCents": 400,
  "discSubtotalCents": 100000,
  "discount": {
    "code": "WELCOME10",
    "percentOff": 10,
    "scope": "first order",
    "window": "7-day renewing window",
    "appliedInHeadlineTotals": false,
    "conditionalTotalCents": 90000
  },
  "addOns": [],
  "addOnCents": 0,
  "shippingCents": 0,
  "shippingLine": "Shipping: Free",
  "taxNote": "Tax, where it applies, is calculated on the invoice.",
  "grandTotalCents": 100000,
  "grandTotalWithFirstOrderDiscountCents": 90000,
  "currency": "USD"
}

Response, text rendering:

Quote for 250 discs (200-399 discs): $1,000.00 total.
Discs: 250 at $4.00 list, $1,000.00 list subtotal. First orders take 10 percent off with code WELCOME10 inside a 7-day renewing window: $900.00 when it applies.
Add-ons: none.
Shipping: Free
Tax, where it applies, is calculated on the invoice.

The headline total is the list total, $1,000.00. The first-orderdiscount is a conditional line only: $900.00 when it applies, neverbaked into the headline.

3. submit_artwork (keyed)

A 1-pixel PNG stands in for the agent-built artwork file here; thesha256 is the real hash of those bytes. This call was made with thefirst-user test organization's key.

Request:

{"jsonrpc": "2.0", "id": 3, "method": "tools/call", "params": {"name": "submit_artwork", "arguments": {"file": {"filename": "worked-example.png", "mediaType": "image/png", "contentBase64": "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg=="}, "sha256": "c414cd0e204de974f73753c7e28d7638e7b3691bb8b1a2bab6b25bb7fed7ce77"}}}

Response, structured content:

{
  "received": true,
  "artworkRef": "art_fc94d730591f03bab798edfe",
  "displayUrl": "https://tap.giving/mcp/artwork/art_fc94d730591f03bab798edfe",
  "sha256": "c414cd0e204de974f73753c7e28d7638e7b3691bb8b1a2bab6b25bb7fed7ce77",
  "validation": {"policy": "permissive", "checks": {"notMalicious": true, "sizeOk": true, "decodable": true}, "findings": ["accepted; vector preferred for production"]},
  "benefits": ["Works with any platform", "No subscription fees", "Durable waterproof PVC with a locked tap chip", "Custom branding from 100 discs", "Free shipping", "Covered by our 30-day money-back guarantee"],
  "preview": {"kind": "on-disc", "shapes": ["round", "square"], "note": "Your design on the disc, cut shape applied. This preview render is the design check at this stage; nothing is emailed at the artwork stage, because no contact is captured yet. The emailed final proof belongs to the order stage, after order setup."},
  "nextStep": "Show the person their design on the disc (the preview image), then capture the contact email at order setup (start_order_intent) and ask the order questions (get_order_questions)."
}

The result also carries the submitted design composited on the discback as image content blocks, one per shape when no shape was given,and its text rendering opens with the test-mode banner, then:"Artwork received: art_fc94d730591f03bab798edfe(worked-example.png, png, 70 bytes)."

4. create_order (no key, idempotency key)

Between artwork and order, get_recap returns a recapRef for theexact inputs the person saw (its cost object is the get_quoteobject above); create_order carries that recapRef. The recap forthis pass was recap_f562143ce62c3282468a7670, with the contactemail among its inputs.

Request:

{"jsonrpc": "2.0", "id": 5, "method": "tools/call", "params": {"name": "create_order", "arguments": {"contactName": "MCP Acceptance", "contactEmail": "[email protected]", "contactPhone": "+17135550199", "organizationName": "MCP Acceptance Test Organization", "quantity": 250, "size": "100mm-round", "mounting": "adhesive", "artworkRef": "art_2ce8de191f7035de811e224b", "recapRef": "recap_f562143ce62c3282468a7670", "exit": "pay_now", "idempotencyKey": "worked-example-2026-11-07-01", "shipTo": {"name": "MCP Acceptance Test Organization", "street": "100 Test Way", "city": "Spring", "state": "TX", "postalCode": "77380", "country": "US", "phone": "+17135550199"}}}}

Response, structured content (abbreviated; the full quote objectfrom step 2 rides as quote):

{
  "orderRef": "mcp:mcp-acceptance-test-church:93f3ebe22527b0b7",
  "invreqKey": "INVREQ:2026-11-07T21:45:50.340Z:[email protected]",
  "exit": "pay_now",
  "quote": {"quantity": 250, "tier": "200-399 discs", "grandTotalCents": 100000},
  "nextStep": "The order is placed. A person from Tap.Giving follows up with the invoice for this order; the person pays it when it arrives."
}

A retry with the same idempotency key and the same payload returnsthis same orderRef; the same key with a different payload is aconflict naming the differing fields.

5. The placement is the whole road (P-16, 2026-11-08)

There is no step 5. Placing the order in step 4 is the end of theserver's road: the order is recorded in the CRM (the invreqKey inthe step 4 response), and the full order is emailed to theTap.Giving team, whose reply in the response (orderEmail) confirmsthe send. A person from Tap.Giving follows up with the actualinvoice; this server issues no invoices and returns no invoicelink. The response's confirmation says exactly that: "Your orderis placed, and a person from Tap.Giving will follow up with yourinvoice."

Reading the order back afterwards is get_order_status with theorganization key (the one keyed read). Invoices a person latercreates in the follow-up, once recorded against the order, surfacethere as read-only state.

Errors

Every tool error returns MCP's standard error content (a text blockreading code: message) plus a structured object:{code, message, retryable, details}. The details object carrieswhat an agent needs to act, for example the differing fields on aconflict. No error ever returns another organization's data, a stacktrace, or a secret.

The two distinctions agents most often get wrong: unauthorizedis about the key itself (malformed or unknown, fix the key), whileforbidden means the key is fine and the record is not yours (donot retry). And not_found is what a cross-organization orderRefreturns on the read paths; forbidden is what the attach pathsreturn when a named order, recap, or artwork belongs to anotherorganization.

This catalog is current as of 2026-11-07, when the live-modeinvoice refusal (invoice_parity_pending) was lifted after thefield-for-field parity check passed; that code no longer exists inthe server.

Keys

An organization key looks like tg_live_<orgslug>_<secret>; a testkey looks like tg_test_<orgslug>_<secret>. Keys are sent asAuthorization: Bearer <key>. Only the SHA-256 hash of a key isstored. A key's mode binds its seat: test keys write test records andmint test invoices; live keys serve production. Real organizationsget a key by emailing [email protected]; the team replies with the keywithin one business day. Evaluating the server? A test key runs thefull keyed journey with no real order and no charge. There is noself-serve signup: email [email protected] and ask for a test key, andthe team replies with one within one business day.

A registry record for this server lives in this repo asserver.json, in the official MCP Registry format:the namespace-tied name, a short description, the server version,and the remote endpoint. The record is created and validated;publishing it to the registry is a separate step, so the server isnot listed yet.

Development

npm install
npm test          # contract tests against the published fact set
npm run typecheck
npx wrangler dev  # local run

Secrets (Stripe keys per mode, the invocation-seat secret) are setwith wrangler secret put and are never committed.