access-engine/workplans/FLEX-WP-0035-per-identity-application-readback.md

id	type	title	domain	repo	status	owner	topic_slug	created	updated	related	state_hub_workstream_id
FLEX-WP-0035	workplan	Per-identity application access readback and readable protected-system registry for user-engine	infotech	access-engine	active	claude	netkingdom	2026-10-09	2026-10-09	USER-WP-0026 USER-WP-0028	cb9755fa-6824-5288-81c4-3aa2fbff1a9f

user-engine (message f1637c32, 2026-10-09, routed by net-kingdom 19a0cbcd) needs to show a signed-in person which applications they can use. Its USER-WP-0026-T03 and USER-WP-0028-T02 are blocked_on access-engine. The PEP stance is already fail-closed: no decision renders unavailable, and allow is never inferred from membership, platform role, registration, or a missing record.

What exists today (2026-10-09 review)

• POST /v1/batch_check takes several resources in one call and returns one decision per resource, each with a lifetime (expires_at) per the decision envelope. Shape-wise this is close to request (1).
• Caller auth authorizes the caller token against every resource.system in the batch (cmd/flex-auth/main.go, /v1/batch_check). The flex-auth-user-engine caller is bound to its own protected system, so a readback across other systems is a 403 today. That is correct behaviour for enforcement, and the reason this needs design rather than a config change.
• There is no generic "may use this application" action. Each package has its own action vocabulary, so "access to system X" has no defined meaning yet.
• There is no registry read endpoint. The protected-system registry is loaded from files and never served.

Define the readback contract

id: FLEX-WP-0035-T01
status: progress
priority: high
state_hub_task_id: "0585a684-d462-5caa-937f-b1730efddbd8"

Decide the action that a readback evaluates per system: a declared application.access action each consumer package must opt into, versus a per-system mapping held in the registry. A system that declares nothing is returned as not_applicable, never allow. State per input class the revocation-visibility deadline the readback carries (§9.7). Decide whether the readback is a decision for audit purposes (decision record, emission) or an explicitly non-enforcing advisory read. A displayed allow must not be usable as a PEP decision by another system.

Gate: written contract in docs/ plus an ADR or decision record; reviewed with user-engine before code.

2026-10-09: activated by the founder. Draft contract docs/application-access-readback.md and FLEX-DEC-2026-019 (proposed). Key finding: each pin loads one consumer's package, so no existing pin can answer across applications. The draft proposes a dedicated readback pin with multi-package mode, a purpose: "readback" binding that keeps decisions non-transferable, and a new optional client_binding manifest field. Sent to user-engine with four review questions. The gate closes on their reply.

Caller authorization for cross-system readback

id: FLEX-WP-0035-T02
status: todo
priority: high
depends_on: [FLEX-WP-0035-T01]
state_hub_task_id: "eb0b6a91-7750-553b-b87f-c4262eb9df07"

Add a distinct caller capability (readback scope) instead of widening the flex-auth-user-engine binding to other systems' check rights. The readback caller must not be able to obtain a decision that another system's PEP would accept, and its decisions must say so in the binding.

Gate: tests prove a readback-scoped token gets 403 on /v1/check for a foreign system and is admitted only on the readback route.

Readable protected-system registry

id: FLEX-WP-0035-T03
status: todo
priority: medium
depends_on: [FLEX-WP-0035-T01]
state_hub_task_id: "5dbb3280-8490-58a5-a0bb-f3883e568f58"

Serve a read-only projection: system id, display name, key-cape client binding. Include the registry-snapshot digest so the catalogue is tied to the same snapshot that decisions record (G1, FLEX-WP-0019). Grants and revocations stay inside access-engine; user-domain admins get no grant surface from this work.

Gate: endpoint plus schema, admitted only for the readback caller, tests.

Deploy to the user-engine pin

id: FLEX-WP-0035-T04
status: wait
needs_human: true
depends_on: [FLEX-WP-0035-T02, FLEX-WP-0035-T03]
blocking_reason: "Live pin change on railiance01 needs founder go."
priority: medium
state_hub_task_id: "82a8a7e6-54e9-5262-a271-24ce2f161362"

Roll the readback route and its caller binding onto flex-auth-user-engine, then hand user-engine the evidence that unblocks USER-WP-0026-T03.