> ## Documentation Index
> Fetch the complete documentation index at: https://docs.endstate.io/llms.txt
> Use this file to discover all available pages before exploring further.
# Test without hardware
> Use test chips to exercise the full verification flow in development — no physical NFC hardware required.
Test chips let you build and verify your integration end-to-end before you have encoded hardware in hand. They behave identically to real chips in every API call — the only difference is how you obtain an `e` value: you generate one on demand via the `/tap` endpoint instead of reading it from a physical tag.
Use this guide to run the complete loop — create a test chip, generate a tap credential, and verify it — entirely with `curl`.
## Full walkthrough
Pair a test chip to an existing unit by setting `is_test: true`. You do not supply a `chip_id` or an initial `e` value — Endstate assigns the `chip_id` for you.
```bash theme={null}
curl -X POST https://api2.endstate.io/v1/chips \
-H "Authorization: Bearer end_sk_test_..." \
-H "Content-Type: application/json" \
-d '{
"unit_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
"is_test": true
}'
```
```json theme={null}
{
"chip_id": "ABCDEF0123",
"is_test": true,
"scan_count": 0,
"created_at": "2026-06-15T10:00:00.000Z",
"unit": {
"id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
"external_id": null,
"name": null,
"attributes": null,
"redirect_url": null,
"created_at": "2026-06-15T09:59:00.000Z",
"collection": {
"id": "8e1a7f50-90ab-4cde-b012-3456789abcde",
"name": "Canvas Tote Collection",
"external_id": null,
"contract": {
"address": "0x1111111111111111111111111111111111111111",
"chain_id": 84532,
"status": "active"
},
"token": { "status": "pending", "serial": null }
}
}
}
```
Note the `chip_id` returned in the response — you use it in every subsequent call. Pairing the chip also triggers issuance: the unit's `token.status` transitions from `"pending"` to `"active"` and a serial number is assigned.
Call the `/tap` endpoint to get a fresh, single-use `e` value. This endpoint is only available on test chips — calling it on a real encoded chip returns `chip.not_a_test_chip`.
```bash theme={null}
curl -X POST https://api2.endstate.io/v1/chips/ABCDEF0123/tap \
-H "Authorization: Bearer end_sk_test_..."
```
```json theme={null}
{
"chip_id": "ABCDEF0123",
"e": "C78566198547116F3A715DC1C62AF96F",
"count": 1
}
```
`count` is the emulated chip counter used to generate this `e` value — it increments with each simulated tap, mirroring how a physical chip's scan counter behaves.
Each call produces a new `e` value. Use it immediately in the next step — it is single-use and cannot be reused.
`/tap` takes no required fields, and an empty body is accepted — with or
without a `Content-Type: application/json` header, the API treats it as `{}`.
Only a **non-empty** body that isn't valid JSON is rejected
(`validation.failed`).
Optionally pass `{ "count": }` in the body to pin the emulated counter for the generated `e` value — it must be greater than the chip's current counter. When omitted, the next counter value is used automatically; most integrations never need to set it.
Submit the `e` value exactly as you would for a real tap. The verify endpoint makes no distinction between test chips and encoded chips at this point — the flow is identical.
```bash theme={null}
curl -X POST https://api2.endstate.io/v1/chips/ABCDEF0123 \
-H "Authorization: Bearer end_sk_test_..." \
-H "Content-Type: application/json" \
-d '{
"e": "C78566198547116F3A715DC1C62AF96F"
}'
```
```json theme={null}
{
"id": "f9e8d7c6-b5a4-3210-fedc-ba9876543210",
"session_token": {
"token": "end_sess_AbCd1234EfGh5678IjKl9012MnOp",
"expires_at": "2026-06-15T10:10:00.000Z",
"scope": {
"chip_id": "ABCDEF0123",
"unit_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
"organization_id": "c0ffee00-1234-5678-90ab-cdef01234567"
}
},
"chip": {
"chip_id": "ABCDEF0123",
"scan_count": 1
},
"unit": {
"id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
"external_id": null,
"name": "Canvas Tote #42",
"attributes": null,
"collection": {
"id": "8e1a7f50-90ab-4cde-b012-3456789abcde",
"name": "Canvas Tote Collection",
"external_id": null,
"contract": {
"address": "0x1111111111111111111111111111111111111111",
"chain_id": 84532,
"status": "active"
},
"token": {
"status": "active",
"serial": 1
}
}
},
"redirect_url": null,
"dry_run": false
}
```
A successful response confirms verification worked. The `session_token` is short-lived proof that the chip was tapped; pass it to a client to authorize unit-scoped actions without exposing your API key.
Call `POST /v1/chips/{chip_id}/tap` again to get a new `e` value for your next verification. Each `e` is single-use — generate a fresh one for each call to the verify endpoint.
```bash theme={null}
curl -X POST https://api2.endstate.io/v1/chips/ABCDEF0123/tap \
-H "Authorization: Bearer end_sk_test_..."
```
You can run this loop as many times as you need during development. `scan_count` increments with each successful verification.
## How test chips compare to encoded chips
| | Encoded chip | Test chip |
| ------------------------- | ------------------------------- | ------------------------------------- |
| **`is_test`** | `false` | `true` |
| **Created with** | `chip_id` + `e` (from hardware) | `is_test: true` (no `chip_id` needed) |
| **`chip_id` assigned by** | You (from the physical tag) | Endstate |
| **`e` value source** | Physical tap of the NFC tag | `POST /v1/chips/{chip_id}/tap` |
| **`/tap` endpoint** | Returns `chip.not_a_test_chip` | Returns a fresh `e` value |
| **Verify endpoint** | Identical behavior | Identical behavior |
| **`scan_count`** | Increments on each verification | Increments on each verification |
Test chips are otherwise indistinguishable from encoded chips through the API. Your verification handler does not need to branch on `is_test`.
To list only your test chips, pass `is_test=true` to the chips list endpoint:
```bash theme={null}
curl "https://api2.endstate.io/v1/chips?is_test=true" \
-H "Authorization: Bearer end_sk_test_..."
```
## Validate without recording a scan
Pass `"dry_run": true` in a verify request to validate an `e` value without
recording a scan or issuing a session token. This is useful for confirming
your integration handles the request/response shape correctly before
committing real scan records. The `e` value is consumed either way — generate
a new one from `/tap` for your next call.
```bash theme={null}
curl -X POST https://api2.endstate.io/v1/chips/ABCDEF0123 \
-H "Authorization: Bearer end_sk_test_..." \
-H "Content-Type: application/json" \
-d '{
"e": "C78566198547116F3A715DC1C62AF96F",
"dry_run": true
}'
```
When `dry_run` is `true`, the response has `dry_run: true`, `session_token` and `id` are `null`, and `scan_count` does not increment.
## Development and production
Test chips are for development only. Production verification requires encoded
NFC hardware chips — physical tags that generate `e` values on each tap.
Before going live, replace test chips with encoded chips and confirm your
integration handles real tap URLs correctly. See [Environments](/environments)
for the API base URL and testing model.
## Next steps
The full production verification guide, including how real tap URLs deliver
the chip\_id and e value.
How chips work, what the e value is, and the full verification model.