Keyban API Client

Python client for the Keyban DPP Passport API. Create and manage model-granularity passports with on-chain certification on Starknet, field-level encryption, and typed Pydantic models.

Features

Model passports — create and update passports certified on Starknet
On-chain certification — automatic W3C Verifiable Credential issuance (P-256 ecdsa-jcs-2019) anchored on Starknet, signed content uploaded to IPFS
Selective certification — certified_paths to choose which fields from data go into the certificate; updating non-certified fields skips re-certification
Field-level encryption — SHA-256 hashing (integrity) or AES-256-GCM (reversible) via PassportData
Typed responses — Pydantic v2 models; py.typed marker for mypy users

Install

pip install keyban-api-client

Requires Python 3.9+.

Quick start

from uuid import UUID
from keyban_api_client import PassportClient

client = PassportClient(api_key="your-api-key")
# base_url defaults to https://api.prod.keyban.io — pass it explicitly for staging/local:
#   PassportClient(api_key="...", base_url="https://api.staging.keyban.io")

app_id = UUID("00000000-0000-0000-0000-000000000000")  # ← replace with your application UUID

passport = client.create_passport_model(
    application=app_id,
    network="StarknetMainnet",
    model_number="my-model-001",
    data=\{"brand": "Acme", "gtin": "3760001000001"\},
    certified_paths=["brand", "gtin"],
)

print(f"Passport ID: \{passport.id\}")
print(f"Token ID:    \{passport.token_id\}")       # derived immediately
print(f"IPFS CID:    \{passport.ipfs_cid\}")       # None right after creation — see below

Certification is asynchronous

When data is provided on a model passport, the backend queues a certification job. The HTTP response returns immediately with token_id populated, ipfs_cid still None, and certification_status="pending". The worker then:

Builds a W3C Verifiable Credential (credentialSubject = byte-for-byte certified content)
Uploads the signed VC to IPFS → populates ipfs_cid
Publishes a certification event on Starknet with the CID, a SHA-256 canonical content hash, and the certifier public key
Marks the passport as certification_status="certified" and stamps certified_at

Latency depends on the network: a few seconds on devnet, typically 15–20 seconds on Mainnet. Poll on certification_status to detect the transition ("pending" → "certified", or "error" if all retries are exhausted):

import time

while True:
    p = client.get_passport(passport.id)
    if p.certification_status == "certified":
        break
    if p.certification_status == "error":
        raise RuntimeError("certification failed")
    time.sleep(3)

Re-certification (triggered by an update_passport_model that changes the certified content) flips certification_status back to "pending" until the new on-chain anchor lands; on success, ipfs_cid and certified_at are updated to the new values. If the update does not change the certificate content (e.g. you touched only a field outside certified_paths), the status stays "certified" and the CID is unchanged — no re-certification is triggered.

Encryption

Protect sensitive fields locally before sending them to the API:

Algorithm	Reversible	Use case
`sha256`	No	Integrity / existence proof
`aes-256-gcm`	Yes	Confidential data (decrypt with the key)

import base64, os
from keyban_api_client import PassportData

# SHA-256 (one-way hash) — encryption_key is NOT set on this path
data = PassportData.create_encrypted(
    confidential_paths=["supplier_id"],
    enc_algorithm="sha256",
    name="Public name",
    supplier_id="SECRET-123",
)
# data.model_dump() → \{"name": "Public name", "supplier_id": "encrypted:sha256:<hex>"\}

# AES-256-GCM (symmetric, reversible). Omit `enc_key` to let the SDK generate one;
# read it back via `data.encryption_key` (only set on the AES path).
data = PassportData.create_encrypted(
    confidential_paths=["serial_number", "brand.supplier_id"],  # dot-notation supported
    enc_algorithm="aes-256-gcm",
    name="Public",
    serial_number="SN-CONFIDENTIAL",
    brand=\{"name": "Public", "supplier_id": "SECRET"\},
)
key_to_persist = data.encryption_key  # base64-encoded 32 bytes — store this in your secret manager
# data.model_dump() → \{"serial_number": "encrypted:aes-256-gcm:<b64>", ...\}

passport = client.create_passport_model(
    application=app_id,
    network="StarknetMainnet",
    model_number="enc-model",
    data=data.model_dump(),
    certified_paths=["serial_number"],
)

Do not log the AES key. Treat data.encryption_key like any other secret — if it leaks into logs, the chiffré can be reversed.

Payload format

Encrypted values carry an encrypted:<algorithm>:<payload> prefix.

SHA-256 payload is hex of sha256(canonical_json_value). Irreversible — used for proof of existence/integrity only.
AES-256-GCM payload is base64(version || nonce || ciphertext || tag) where version = 0x01, nonce is 12 bytes, and the AEAD tag (16 bytes) is appended to the ciphertext by cryptography's AESGCM. AAD is the literal byte string b"v1:aes-256-gcm".

Security: create_encrypted raises ValueError if a confidential_paths entry does not exist in the data. This prevents silently shipping unencrypted secrets on a typo.

Filtering, pagination, listing

from keyban_api_client import FilterOperator

# Filter values are strings — convert datetimes with .isoformat(), UUIDs with str(...)
filters = [
    FilterOperator(field="granularity", operator="eq", value="model"),
    FilterOperator(field="modelNumber", operator="eq", value="my-model-001"),
]
page = client.list_passports(filters=filters, current_page=1, page_size=50)

for p in page.data:
    print(f"- \{p.id\} \{p.granularity\} \{p.model_number\}")
print(f"total matching: \{page.total\}")

# Paginate. page_size > 100 returns HTTP 400 (not silently capped).
all_passports = []
cursor = 1
while True:
    resp = client.list_passports(current_page=cursor, page_size=100)
    all_passports.extend(resp.data)
    if not resp.data or len(all_passports) >= resp.total:
        break
    cursor += 1

Today the public passport endpoint only accepts eq on granularity and modelNumber. Other field/operator combinations return HTTP 400. field uses the backend (camelCase) name — modelNumber, not model_number.

Selective certification with `certified_paths`

By default (or with certified_paths=[]) the full data object is certified. Pass specific paths to certify only a subset — updating non-certified fields won't trigger re-certification:

passport = client.create_passport_model(
    application=app_id,
    network="StarknetMainnet",
    model_number="selective",
    data=\{"brand": "Acme", "gtin": "3760001000001", "notes": "internal memo"\},
    certified_paths=["brand", "gtin"],
)

# Update a non-certified field — NO re-certification
client.update_passport_model(
    passport.id,
    data=\{"brand": "Acme", "gtin": "3760001000001", "notes": "updated memo"\},
)

# Update a certified field — re-certification triggers; new ipfs_cid after the job runs
client.update_passport_model(
    passport.id,
    data=\{"brand": "NewBrand", "gtin": "3760001000001", "notes": "updated memo"\},
)

# Change the selection itself — re-certification triggers
client.update_passport_model(passport.id, certified_paths=["brand", "gtin", "notes"])

The backend only re-certifies when the resulting certificate content actually changes (content hash differs).

Error handling

from uuid import UUID
import requests
from keyban_api_client import PassportClient, KeybanAPIError

with PassportClient(api_key="...") as client:
    try:
        passport = client.get_passport(UUID("00000000-0000-0000-0000-000000000000"))
    except KeybanAPIError as e:
        print(e)                 # e.g. "HTTP 404: Not Found"
        print(e.status_code)     # 404
        print(e.detail)          # full RFC 7807 body: \{"status", "title", "detail", ...\}
    except requests.RequestException as e:
        # DNS failures, connection refused, read timeouts — see note below
        print(f"network error: \{e\}")

KeybanAPIError inherits from requests.HTTPError and is raised on any non-2xx HTTP response. Its __str__ renders as "HTTP \{status\} \{title\}: \{detail\}", with one shortcut: when title == detail (common for 404 Not Found, 401 Unauthorized, …) the message collapses to "HTTP \{status\}: \{title\}". Structured access via .status_code and .detail remains available for programmatic flows.

Network-level failures are not wrapped. Connection refused, DNS failures, TLS errors, and read timeouts surface as raw requests.exceptions.* (they never reach the HTTP layer where KeybanAPIError is raised). Catch requests.RequestException alongside KeybanAPIError if you need a single safety net.

API reference

`PassportClient(api_key, base_url="https://api.prod.keyban.io", api_version="v1", timeout=30)`

Method	Signature	Notes
`list_passports`	`(filters=None, current_page=1, page_size=10) -> PassportListResponse`	Any granularity. `page_size > 100` → `HTTP 400` from the backend (no client-side check).
`get_passport`	`(passport_id: UUID) -> Passport`	Any granularity. The `UUID` type is advisory — strings are forwarded as-is and only validated server-side.
`create_passport_model`	`(*, application, network, model_number, data=None, certified_paths=None) -> Passport`	Granularity is always `model`.
`update_passport_model`	`(passport_id, *, data=None, certified_paths=None) -> Passport`	Re-certification triggers automatically when the certificate content changes.
`close()`	—	Closes the HTTP session. Also supports `with PassportClient(...) as client:`.

Public models

Symbol	Role
`Passport`	Response model for a passport — see full field list below
`PassportListResponse`	`\{data: List[Passport], total: int\}`
`PassportData`	Helper to build the `data` dict — accepts arbitrary keyword arguments (`extra='allow'`); converts `date` to ISO strings and exposes `create_encrypted(...)`. Note: `datetime` values are truncated to date (the time component is dropped) — pre-format with `dt.isoformat()` if you need full timestamps.
`FilterOperator`	`\{field: str, operator: str, value: str\}` — values are forwarded with no client-side validation.
`KeybanAPIError`	Exception raised on any non-2xx HTTP response. Network-level failures are raised as `requests.exceptions.*` and not wrapped.

`Passport` fields

Field	Type	Notes
`id`	`UUID`	Passport identifier.
`application`	object with `.id: UUID`	Application the passport belongs to. Access via `passport.application.id`. The concrete class is internal and not part of the public API.
`network`	`str`	e.g. `"StarknetMainnet"`, `"StarknetSepolia"`. The SDK forwards the string unchanged; the backend is the source of truth for the accepted set.
`granularity`	`str`	`"model"`, `"batch"`, or `"item"`. This SDK only creates `"model"`; reads are agnostic.
`model_number`	`Optional[str]`	Identifier for model granularity.
`batch_number`	`Optional[str]`	Identifier for batch granularity.
`item_number`	`Optional[str]`	Identifier for item granularity.
`data`	`Optional[Dict[str, Any]]`	Arbitrary passport data.
`certified_paths`	`Optional[List[str]]`	Dot-notation paths selecting which fields of `data` go into the certificate. Empty/`None` ⇒ the entire `data` is certified.
`token_id`	`Optional[str]`	On-chain identifier, populated immediately on create.
`ipfs_cid`	`Optional[str]`	IPFS CID of the signed VC. `None` right after create/update — see the "Certification is asynchronous" section.
`certification_status`	`Optional[str]`	`"pending"` while the certify job is queued or retrying, `"certified"` once the on-chain transaction succeeds, `"error"` once all retries are exhausted. Read-only.
`certified_at`	`Optional[datetime]`	UTC timestamp of the last successful certification, `None` until the cert job completes. Read-only.
`allowed_claim_email`	`Optional[str]`	Email allowed to claim this passport (item granularity only).
`created_at`	`datetime`	Returned as-is from the backend; expected to be timezone-aware UTC.
`updated_at`	`datetime`	Returned as-is from the backend; expected to be timezone-aware UTC.

API endpoints

All operations go through /v1/dpp/passports:

Endpoint	Method
`/v1/dpp/passports`	GET, POST
`/v1/dpp/passports/:id`	GET, PATCH

Migrating to 2.0

2.0 focuses the public surface on passport-model operations. If you are on 0.0.x, apply both the 0.0.x → 1.0.0 steps and the 1.0.0 → 2.0 steps below.

Quick upgrade

pip install --upgrade keyban-api-client

Before / after

# BEFORE (1.0.0)
from keyban_api_client import DppClient, CreatePassportRequest, ProductFields

client = DppClient(
    base_url="https://api.prod.keyban.io",
    api_key="...",
)
passport = client.create_passport(CreatePassportRequest(
    application=UUID("00000000-0000-0000-0000-000000000000"),
    network="StarknetMainnet",
    granularity="model",
    modelNumber="my-model",
    data=\{"brand": "Acme"\},
    certifiedPaths=["brand"],
))
client.close()

# AFTER (2.0)
from keyban_api_client import PassportClient, PassportData

client = PassportClient(api_key="...")  # base_url defaults to prod
passport = client.create_passport_model(
    application=UUID("00000000-0000-0000-0000-000000000000"),
    network="StarknetMainnet",
    model_number="my-model",
    data=\{"brand": "Acme"\},
    certified_paths=["brand"],
)
client.close()

Renames

1.0.0	2.0.0
`DppClient`	`PassportClient`
`DppPassport`	`Passport`
`ProductFields`	`PassportData`
`ProductClient` (alias)	removed — use `PassportClient`

Removed (with replacement guidance)

Removed	Replacement
`client.create_passport(data)`	`client.create_passport_model(**kwargs)` — kwargs-only; granularity always `model`
`client.update_passport(id, data)`	`client.update_passport_model(id, **kwargs)`
`client.delete_passport(id)`	No SDK replacement — model passports anchor on-chain records and are intended to remain addressable
`CreatePassportRequest`	Pass fields directly as keyword arguments to `create_passport_model(...)`
`UpdatePassportRequest`	Pass fields directly as keyword arguments to `update_passport_model(...)`
`create_filter(field, op, value)`	`FilterOperator(field=..., operator=..., value=...)`
`search_passports(client, filters)`	`client.list_passports(filters=filters).data`
`QueryParams`, `DynamicFieldDef`, `Application`	Unused in public flows; made internal or removed
`playground.py`	Use the examples in this README. End-to-end tests (`test_client.py -m api`) are kept in the source repository, not shipped on PyPI.

Constructor signature

PassportClient.__init__ swaps parameter order: api_key comes first, base_url is optional and defaults to "https://api.prod.keyban.io".

# 1.0.0 — base_url required and first
DppClient(base_url="...", api_key="...")

# 2.0.0 — api_key first; base_url optional
PassportClient(api_key="...")
PassportClient(api_key="...", base_url="https://api.staging.keyban.io")

Write methods: kwargs-only, snake_case

create_passport_model and update_passport_model take named keyword arguments only. granularity is no longer part of the public surface (it is always "model" for these methods). Camel-case aliases (modelNumber, certifiedPaths) are not accepted — use model_number, certified_paths.

Behavioral changes

FilterOperator.value is now str. Non-string values raise a Pydantic validation error. Convert explicitly: value=str(x), value=dt.isoformat().
page_size > 100 is no longer silently capped. The backend returns HTTP 400 with a clear error. Use page_size<=100 and paginate.
Missing confidential_paths raises. PassportData.create_encrypted(confidential_paths=["typo"], ...) now raises ValueError instead of logging a warning and leaving the data unencrypted — this prevents silent security failures.
KeybanAPIError.__str__ format changed. print(e) now renders "HTTP 403 Forbidden: Invalid API key." instead of just "Forbidden". Attributes e.status_code and e.detail are unchanged. If your code parses str(e), switch to the structured attributes.
network is no longer validated client-side. The backend validates; the SDK passes the string through, so new networks work without a client upgrade.

Read access on key passport fields

In 0.0.x, custom data fields lived at the top level of Product/DppPassport (product.name, product.brand, …). On Passport, custom data is nested under data:

# BEFORE (0.0.x)
name = passport.name

# AFTER (2.0)
name = (passport.data or \{\}).get("name")

Anything not in the closed field list (id, application, network, granularity, model_number, batch_number, item_number, data, certified_paths, token_id, ipfs_cid, allowed_claim_email, created_at, updated_at) is now in passport.data.

From 0.0.x

Apply the 0.0.x → 1.0.0 steps first:

Move any status-driven workflow off the request body. Passports are always published from the user's perspective; the SDK injects status: "published" internally on create where the backend currently requires it.
certifiedPaths (renamed certified_paths in 2.0) is available again on model passports. Omit or pass an empty list to certify the full data.
The old "product" vocabulary (ProductClient, ProductFields, CreateProductRequest, …) has been fully replaced. Follow the renames table above.
Move custom-field reads from passport.<field> to passport.data["<field>"] (see the section above).

Then apply the 1.0.0 → 2.0 changes listed in this document.

Changelog

The full history is maintained in CHANGELOG.md in the source repository. Highlights:

2.0.2 — Documentation pass: filter example aligned with the operators the backend actually accepts (eq on granularity / modelNumber); AES payload format documented; KeybanAPIError __str__ and network-error handling clarified; passport.<field> → passport.data["<field>"] migration note added.
2.0.1 — create_passport_model re-injects status: "published" to match the backend's Draft/Published flow (passports are certifiable immediately on create again).
2.0.0 — Public surface scoped to model-granularity passports. Renames: DppClient → PassportClient, ProductFields → PassportData. See the migration section above.

License

MIT — this client is part of the DAP (Digital Asset Platform) by Keyban project.

Features​

Install​

Quick start​

Certification is asynchronous​

Encryption​

Payload format​

Filtering, pagination, listing​

Selective certification with certified_paths​

Error handling​

API reference​

PassportClient(api_key, base_url="https://api.prod.keyban.io", api_version="v1", timeout=30)​

Public models​

Passport fields​

API endpoints​

Migrating to 2.0​

Quick upgrade​

Before / after​

Renames​

Removed (with replacement guidance)​

Constructor signature​

Write methods: kwargs-only, snake_case​

Behavioral changes​

Read access on key passport fields​

From 0.0.x​

Changelog​

License​