The Four Questions of Delegated Work, and the Invariants That Compose Their Answers
Delegated work forces four separate continuity questions: request provenance, identity attribution, target-applicable authority, and continuing work justification. Their answers compose through a common boundary contract: authoritative sources, bound and correlated evidence, explicit lifecycle semantics, local decisions, and declared failure behavior. Current proposals fill different parts of that contract; narrow profiles adopted one boundary at a time offer a more credible path than one universal delegation artifact.
A Vocabulary, a Rubric, and a Living Map for the Four Questions
Continuity Is Not One Thing argues that delegated work poses four independently governed continuity questions. This companion carries the parts built to be revised rather than to last: a vocabulary that separates facts from evidence, artifacts, authorities, decisions, and state; a twelve-question rubric a working group can apply to any proposal without accepting anyone’s architecture; worked evaluations of Transaction Tokens and Identity Chaining; the sixteen active OAuth working-group documents classified against the framing; and the two-layer standards map with dated versions and statuses.
Re-subjecting across a SaaS boundary is a mint, not an attenuation, so the IdP must issue each onward grant. ID-JAG covers the first hop, where an application holds the user’s ID Token or SAML assertion to exchange. Subsequent hops hold no end-user credential, which leaves a gap: the intermediate has nothing to present to the IdP to continue the chain. The Identity Continuation Assertion fills it. It is a short-lived, sender-constrained JWT, issued by a Chain Authority the IdP trusts, that carries opaque evidence of the in-flight delegation and is presented as the Token Exchange subject token to request an onward ID-JAG. It is evidence, not authority: it carries no subject and grants no access, the IdP resolves the target audience’s subject and re-decides at every hop, and the continuation handle never reaches a Resource Server.
In Cross-App Access, a single signed-in user’s identity has to cross applications that each name them under a different subject. Workload identity proves which service is calling, not which user delegated the work, and offline attenuation can narrow authority it already holds but cannot create a binding to a name it was never given. So crossing a subject namespace is a mint, not an attenuation: only the IdP or broker that owns the mapping can issue new audience-scoped identity evidence, while the destination Authorization Server still applies its own policy and mints the access token. The same shape holds on the authorization axis, where a different scope or policy model forces a non-amplifying re-mint rather than a narrowing. The open question is not whether that mapping authority is in the loop but how it is invoked: caller-pushed continuation, resource-pulled resolution, or another profile that preserves the trust invariant.