Take the reading.
Measure the fleet without ingesting the cargo.
Open the Console
Port is the customer-data boundary. Model state, raw responses, credentials, and PII stay inside customer infrastructure; only the derived evidence needed for the record crosses the Port. Content a customer chooses to preserve alongside a record travels a separate, opt-in path as ciphertext it encrypted itself — Planisphere receives neither the plaintext nor the key.
Where this instrument sits.
Astrolabe takes the reading, Backstaff keeps the record, and Starboard steers the fleet. Each instrument inherits the same proof object without moving the underlying cargo.
Port · AI Evidence Boundary.
A hosted AI tool is a black box. Every prompt opens a connection to a model provider; every response carries the provider’s posture; every audit log lives on the vendor’s servers under the vendor’s schema. A firm that wants to measure the tool runs into the same wall every time: how do we evaluate behavior without ingesting the cargo.
The Port is the answer. It is the named, typed, code-enforced boundary between Planisphere’s measurement substrate and the customer’s data plane. Only sha-pinned evidence metadata crosses the Port outward; raw probe responses, callable references, secrets, and customer PII never do. The boundary is not a paragraph in a contract — it is a frozen dataclass in planisphere.backstaff.port and a continuous-integration test that fails the build if anything else tries to cross.
from planisphere.backstaff.port import PORT — that is the answer on the record.
The Port.
The porthole is the visual claim: a structural opening with two reinforcing rings, a cross-brace, and four rivets — designed to let exactly one well-typed object through and absolutely nothing else.
planisphere.tests.test_port_contract — the build fails if either list is silently expanded.
What crosses.
The boundary exposes only the derived artifacts needed for the evidence record. The API reference is canonical for the current record contract. Each artifact is hashed, aggregated into the canonical Merkle root, and covered by the receipt signature.
from planisphere.backstaff.port import PORT
PORT.crosses
# ("AttestationManifest",
# "attestation_root",
# "fleet_sha256",
# "spectral_geometry_sha",
# "per_adapter_signature",
# "fleet_grades_csv",
# "nist_controls",
# "rank_collapse_attestation")What doesn’t.
The never_crosses tuple is the structural commitment. These seven classes of object never traverse the Port — not because someone promised, but because the CI test fails the build if they appear in any payload that crosses. "We don’t exfiltrate your data" is a marketing claim; this list is the form-factor that lets the firm verify the claim against the running system.
PORT.never_crosses
# ("raw_probe_responses",
# "callable_references",
# "api_keys",
# "bearer_tokens",
# "customer_pii",
# "raw_behavioral_signature_vector",
# "raw_rank_trajectory")
Enforcement: editing PortContract.crosses or PortContract.never_crosses without updating planisphere.tests.test_port_contract fails the build. The two lists are the contract; the test is the proof. The customer’s security team verifies the contract by running the test on a published commit.
The Universal Container.
The Port’s value is that it is content-agnostic. A legal-research AI, a K-5 grader fleet, a defense-procurement classifier, a clinical-decision support tool — all of them are universal containers: hosted, opaque, vendor-controlled. The Port does not care what kind of cargo the container holds. It cares about the boundary itself, and the form-factor of the attestation that emerges from inside it.
PORT.never_crosses — lives here and never leaves.planisphere.tests.test_port_contract. Every commit, every artifact crossing the boundary is checked against the contract. The build fails if either list is silently expanded.The fleet.
The customer’s tool is the merchant ship. Our fleet is what we send out from the Port to inspect it. Six classes — each named in web/icons.html, each tuned to a different measurement posture.
Port and Starboard.
The Port is one half of a paired schema. Its sibling is the Starboard — the outbound surface from which the *-board verticals emit. Together they name the entire Planisphere boundary: the universal container docks at the Port; the per-vertical attestation report emits from the Starboard.
*-board is an Astrolabe audit-render.*-board verticals emit here, each carrying its domain’s mark. War-board (Defense). School-board (Education). Law-board (Law). Medicine-board (forthcoming). Each is a per-domain Astrolabe audit-render + sub-mark.Verification, not disclosure.
The market’s instinct is to demand disclosure — show me the model, show me the prompts, show me the data. That request is unanswerable for a frontier vendor and undesirable for a regulated customer. The Port resolves the standoff by shaping the boundary itself so neither side has to disclose anything sensitive: the vendor’s weights stay with the vendor, the customer’s matter stays with the customer, and the attestation root is verifiable by any third party from the manifest and the public key alone.
That is the form of proof a court can rely on and a firm can produce without waiving anything. The seven entries in PORT.never_crosses are the runtime witness that the boundary holds.
Next step.
Start with a free test key and integrate through the Port boundary. Sandbox receipts are visibly non-production; paid checkout with the same email upgrades the tenant and rotates the key. The vendor never sees us; we never see the customer’s matter.
planisphere.backstaff.port.PORT ———