What it calls

SuperExchange reads SuperPipeline and Accounts only through their public APIs, and owns neither one’s data.

Accounts (ORG_PLANE_URL)

Every call carries SuperExchange’s service credential (ORG_PLANE_SERVICE_CREDENTIAL) as a bearer. A plane that cannot answer is never read as “nobody”.

Request	For
GET /api/identities/matrix/:mxid	The principal a Matrix sender is linked to; 404 is nobody (a link still in its 15-minute hold reads as nobody too)
GET /api/principals/:id	What kind of principal that is (human, agent, service), and how a receipt names them: display name, else handle
POST /api/token/assertion { identity: { system: "matrix", externalId }, audience }	An assertion of the sender for SuperPipeline. Its sub must be the principal resolved above, or the answer is refused
GET /api/principals?kind=human	The workspace’s people with their role, for an escalation: owners and admins, not suspended
GET /api/principals/:id/identities?system=matrix	Each such admin’s linked Matrix id; an admin who linked none is not invited
POST /api/token/service { audience }	SuperExchange’s own token for SuperPipeline (audience SUPERPIPELINE_URL), held until shortly before it expires

SuperPipeline (SUPERPIPELINE_URL)

As the person who answered

Each with Accounts’ assertion for that person.

Request	For
POST /v1/boards/:boardId/gates/:gateId/resolve	A gate answer: { decision, comment?, approvalSubjectId?, approvalSubjectDigest? }
POST /v1/boards/:boardId/elicitations/:elicitationId/answer	A question’s answer
POST /v1/boards/:boardId/gates/:gateId/delivery	A follow-up: { liveUrl } or { mode: "automatic" }
POST /v1/boards/:boardId/cards/:cardId/resume	A waiting card resumed: { comment, toStageKey?, expectedWaitId }
POST /v1/boards/:boardId/cards/:cardId/archive	A waiting card archived: { expectedWaitId, comment? }
POST /v1/boards/:boardId/gates/:gateId/pull-back	A pull-back: { comment }
POST /v1/boards/:boardId/cards/:cardId/checks/:name/override	A check override: { comment }

As itself

With its own service token, on SuperPipeline’s service routes.

Request	Scope	For
GET /v1/boards/:boardId/gates/pending	gates:read	The gate sweep
GET /v1/boards/:boardId/gates/:gateId	gates:read	One gate, and how it was decided
GET /v1/boards/:boardId/elicitations/pending	approval-requests:relay	The question sweep
GET /v1/boards/:boardId/deliveries/pending	gates:read	The follow-up sweep (SuperPipeline v0.0.30 or later)
GET /v1/boards/:boardId/attention/pending	gates:read	The waiting-card sweep (SuperPipeline v0.0.30 or later)
GET /v1/boards/:boardId/cards/:cardId/checks	gates:read	An escalation of overdue checks, and re-posting for a joining admin (SuperPipeline v0.0.30 or later)

The homeserver (MATRIX_HOMESERVER_URL)

As the appservice, with MATRIX_AS_TOKEN, through the client-server API: registering and naming the speaker, the appservice login that gives the speaker its device, creating rooms, resolving an alias, reading a room’s encryption state and joined members, inviting, sending (encrypted or not), and the encryption machinery’s own requests (keys upload, query and claim, to-device messages).