# Payline Developers

- [Build with Payline](https://developers.paylinedata.com/index.md): Create Applications through the API and let merchants complete and sign securely.
- [Credentials and request safety](https://developers.paylinedata.com/credentials.md): Use environment-local credentials, show-once delivery and deliberate replacement.
- [Create and recover Applications](https://developers.paylinedata.com/create-applications.md): Persist one request identity, resolve pricing once and recover safely after uncertainty.
- [Merchant completion and signing](https://developers.paylinedata.com/merchant-completion.md): Let the merchant complete, review and sign without manufacturing approval or consent.
- [Poll, retrieve and download](https://developers.paylinedata.com/retrieve-applications.md): Separate safe lifecycle polling, sensitive current data and immutable signed artifacts.
- [Explicitly reissue unsigned access](https://developers.paylinedata.com/reissue-access.md): Replace an eligible predecessor once, preserving the same Application and merchant progress.
- [Create or recover the same durable Application](https://developers.paylinedata.com/api-reference/create-or-recover-the-same-durable-application.md): UUID v4 identity is environment + tenant + stable caller + requestId. Equivalent normalized original intent recovers regardless of later merchant edits, defaults, allocation or lifecycle; different intent conflicts. Pricing defaults resolve once. Protected receipt comparison is encrypted. No email,…
- [Discover current eligible local allocation users](https://developers.paylinedata.com/api-reference/discover-current-eligible-local-allocation-users.md)
- [Retrieve current authorized answers and resolved pricing](https://developers.paylinedata.com/api-reference/retrieve-current-authorized-answers-and-resolved-pricing.md): All 46 canonical fields and field states, including merchant edits and raw protected values. Audit records the verified caller/key and scope before any response release; failed or ambiguous commit returns a safe 503. Values never fall back to signed snapshots or current defaults. No query parameters…
- [Poll signing acceptance and independent artifact readiness](https://developers.paylinedata.com/api-reference/poll-signing-acceptance-and-independent-artifact-readiness.md): Accepted signing stays accepted if finalization fails. No protected answers, private storage identifiers or merchant URL. Contradictory evidence is unavailable. No query parameters.
- [Download an existing immutable signed artifact](https://developers.paylinedata.com/api-reference/download-an-existing-immutable-signed-artifact.md): Current authorization and exact Application/version/kind are rechecked on every download. Private PDF size/checksum and immutable lineage must pass before audit commit and streamed byte release. No regeneration, redirect, Blob URL/key, merchant cookie, query parameters or range delivery. Maximum obj…
- [Explicitly replace eligible unsigned access](https://developers.paylinedata.com/api-reference/explicitly-replace-eligible-unsigned-access.md): Requires a canonical draft/in_progress Application, one authoritative session and the expected active, expired or revoked predecessor. No archive, merchant linkage, ambiguous authority, building/active signing input or signing ceremony. Atomically retires the predecessor, issues one new 30-day grant…
- [Recover current handoff without issuance or renewal](https://developers.paylinedata.com/api-reference/recover-current-handoff-without-issuance-or-renewal.md)

## OpenAPI Specs

- [applications-v1](/openapi/applications-v1.json)


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