Use this when a task needs a decision you can defend — refunds, eligibility, policy compliance,
safety approvals — or a machine-checkable proof rather than a guess. It drives the NSR reasoning
API at api.nsr.stateset.com directly over HTTP or through the stateset-nsr-mcp MCP server.
NSR returns one of exactly three accountable outcomes — approved, denied, or refused — with
cited rules, a replayable derivation, and a sha256 policy pin. There is no path from an ungrounded
model answer to a confident approval.
Connect
Base URL: https://api.nsr.stateset.com. On every call send X-API-Key: nsr_… and
X-Org-ID: <your org> (a Authorization: Bearer nsr_… header is accepted in place of the API-key
header). Get a key in the console: nsr.stateset.com → API setup → Organization API keys; the
secret is shown once.
Prefer MCP if your harness speaks it — 36 typed tools, retry-safe, with client-side validation:
nsr_decide is the flagship tool; nsr_verify_proof, nsr_record_outcome and nsr_calibration
close the proof and outcome loops.
Make a verified decision
POST /v1/decisions
Read from the response:
decision — approved | denied | refused. Treat refused as “stop and verify”, never as a
soft yes.proof.cited_rules, proof.derivation — the rules and replayed steps the verdict stands on.
proof.request_policy_hash pins the exact policy inputs.refusal.missing_facts — unsatisfied premises [{predicate, args, needed_by_rule}]. Look each
one up with your tools, assert it, and retry. Absent on safety-gated refusals; those need a
human, not a retry.verifiable_bundle — present only on approvals that declared an authorization_goal; see below.
Verify the proof independently
An approval’s verifiable_bundle ({facts, rules, proof, org_id}) is self-contained. POST it
verbatim to POST /v1/proofs/verify — a stateless kernel that reads no tenant state — and require
{"verified": true} before acting on a high-stakes approval. A failure returns the located reason
and step.
Report what actually happened
Send external_ref (your order or ticket id) on the decide, then close the loop:
Outcomes: honored | reversed | overridden | escalated. This feeds
GET /v1/decisions/calibration — ECE and reliability bins — which tells you whether NSR’s stated
confidence can be trusted at each level.
Teach durable policy
POST /api/v1/rules — store an org rule. Shape: head_predicate, head_args,
body: [{predicate, args, negated?}]. Intent comes from head naming (may_* permits,
*_blocked denies, *_requires_review) or an explicit effect.POST /api/v1/rules/lint before install; POST /api/v1/rules/batch to load a book. Decide with
hydrate_org_context: true to use stored policy.POST /api/v1/facts and entities for org knowledge; POST /api/v1/backward-chain proves against
the stored org KB only.
Two encodings that trip agents up
- Facts are an envelope:
{"predicate": {"name": "…", "args": […]}} — not a flat atom.
- Request-scoped rules use
if / then atoms keyed by name; stored rules use
head_predicate / head_args / body atoms keyed by predicate. The error messages do not
always say which one was expected.
Guardrail
Before any consequential action — refund, access grant, data change — decide first, act only on
approved, and log decision_id and proof.request_policy_hash with the action. On refused,
gather the named missing facts and retry. On requires_human_review, escalate.
Further reading
Last modified on August 31, 2026
