fix(api): read the error code before the status

A read-failure primitive decided from the status alone, so a 401 from a
step-up or re-proof gate would have read as an ended session and sent
the reader to sign-in. The code now decides first and the status is the
fallback for codes it does not know.

The two invitation routes answer an unknown name or e-mail with
sharing.invite.no_account. Both have a second 404 with a different next
step, and since every error now carries a code the clients match on it
instead of on the status. The status defaults move into a module the
client can import, and the contract text no longer says these arms
carry no code.

src/lib/__tests__/api-handler-error-request-id.test.ts

@@ -24,9 +24,9 @@ import { apiHandler, HttpError } from "@/lib/api-handler";
 import {
   apiError,
   apiSuccess,
-  defaultErrorCodeForStatus,
   withErrorEnvelopeDefaults,
 } from "@/lib/api-response";
+import { defaultErrorCodeForStatus } from "@/lib/api/default-error-codes";
 
 const INCOMING = "3f9a2c1b-0000-4000-8000-000000000001";
 

src/lib/api-response.ts

@@ -2,6 +2,8 @@ import { isIP } from "node:net";
 import { NextResponse } from "next/server";
 import type { ZodError, ZodIssue } from "zod/v4";
 
+import { defaultErrorCodeForStatus } from "@/lib/api/default-error-codes";
+
 export function apiSuccess<T>(data: T, status = 200) {
   return NextResponse.json({ data, error: null }, { status });
 }
@@ -308,52 +310,6 @@ function isPlainObject(value: unknown): value is Record<string, unknown> {
   return typeof value === "object" && value !== null && !Array.isArray(value);
 }
 
-/**
- * The `meta.errorCode` an error envelope carries when its route named none.
- *
- * `meta.errorCode` is what a client is told to branch on, and roughly half of
- * the refusals in the tree carried one: the rest answered prose alone, so a
- * client could branch on the code for one 404 and had to fall back to the
- * status for the next. Every error envelope now has a code. A route that names
- * its own keeps it; one that does not gets the status's code from this table,
- * so the generic family is predictable from the status alone and a client
- * never has to special-case an absent field.
- *
- * Deliberately coarse. These say which kind of refusal it was, never why —
- * a route that has a reason worth branching on names its own code. Statuses
- * not listed fall back to `http.client_error` / `http.server_error`.
- */
-export const DEFAULT_ERROR_CODES = {
-  400: "http.bad_request",
-  401: "http.unauthenticated",
-  403: "http.forbidden",
-  404: "http.not_found",
-  405: "http.method_not_allowed",
-  409: "http.conflict",
-  410: "http.gone",
-  413: "http.payload_too_large",
-  415: "http.unsupported_media_type",
-  422: "http.invalid",
-  429: "http.rate_limited",
-  500: "http.internal",
-  502: "http.bad_gateway",
-  503: "http.unavailable",
-  504: "http.gateway_timeout",
-  client: "http.client_error",
-  server: "http.server_error",
-} as const;
-
-/** The default code for an error status, see {@link DEFAULT_ERROR_CODES}. */
-export function defaultErrorCodeForStatus(status: number): string {
-  const listed = (DEFAULT_ERROR_CODES as Record<number, string | undefined>)[
-    status
-  ];
-  if (listed) return listed;
-  return status >= 500
-    ? DEFAULT_ERROR_CODES.server
-    : DEFAULT_ERROR_CODES.client;
-}
-
 /**
  * Complete an error envelope: `meta.requestId` always, and `meta.errorCode`
  * from the status when the route named none.
@@ -362,7 +318,7 @@ export function defaultErrorCodeForStatus(status: number): string {
  * envelope carries the full request id beside the `x-request-id` header, so a
  * client behind a proxy that strips headers can still show the id a person
  * reads out to the operator, who finds the event in the admin log with it.
- * The code follows {@link DEFAULT_ERROR_CODES}.
+ * The code follows `DEFAULT_ERROR_CODES` (`src/lib/api/default-error-codes.ts`).
  *
  * Applied once, by `apiHandler`, to whatever the handler answered, so a route
  * that builds its error with `apiError`, with `NextResponse.json` by hand or by

src/lib/api/default-error-codes.ts

@@ -0,0 +1,45 @@
+/**
+ * The `meta.errorCode` an error envelope carries when its route named none.
+ *
+ * `meta.errorCode` is what a client is told to branch on, and roughly half of
+ * the refusals in the tree carried one: the rest answered prose alone, so a
+ * client could branch on the code for one 404 and had to fall back to the
+ * status for the next. Every error envelope now has a code. A route that names
+ * its own keeps it; one that does not gets the status's code from this table,
+ * so the generic family is predictable from the status alone and a client
+ * never has to special-case an absent field.
+ *
+ * Deliberately coarse. These say which kind of refusal it was, never why —
+ * a route that has a reason worth branching on names its own code. Statuses
+ * not listed fall back to `http.client_error` / `http.server_error`.
+ */
+export const DEFAULT_ERROR_CODES = {
+  400: "http.bad_request",
+  401: "http.unauthenticated",
+  403: "http.forbidden",
+  404: "http.not_found",
+  405: "http.method_not_allowed",
+  409: "http.conflict",
+  410: "http.gone",
+  413: "http.payload_too_large",
+  415: "http.unsupported_media_type",
+  422: "http.invalid",
+  429: "http.rate_limited",
+  500: "http.internal",
+  502: "http.bad_gateway",
+  503: "http.unavailable",
+  504: "http.gateway_timeout",
+  client: "http.client_error",
+  server: "http.server_error",
+} as const;
+
+/** The default code for an error status, see {@link DEFAULT_ERROR_CODES}. */
+export function defaultErrorCodeForStatus(status: number): string {
+  const listed = (DEFAULT_ERROR_CODES as Record<number, string | undefined>)[
+    status
+  ];
+  if (listed) return listed;
+  return status >= 500
+    ? DEFAULT_ERROR_CODES.server
+    : DEFAULT_ERROR_CODES.client;
+}

src/lib/api/read-failure.ts

@@ -1,3 +1,6 @@
+import { AUTH_ERROR_CODES, REPROOF_REQUIRED_CODE } from "@/lib/api-errors";
+import { DEFAULT_ERROR_CODES } from "@/lib/api/default-error-codes";
+
 import { ApiError } from "./api-fetch";
 
 /**
@@ -12,12 +15,45 @@ import { ApiError } from "./api-fetch";
  *  - `throttled`: 429. The read budget is spent for now; an immediate retry
  *    would only be refused again.
  *  - `failed`: everything else, a real read failure worth a retry.
+ *
+ * The code decides before the status. A 401 is not always an ended session:
+ * a step-up or re-proof gate answers 401 too, with the session intact, and
+ * sending that reader to sign-in would end a session that was fine. So a
+ * code that names a missing proof reads as `failed`, a code that names an
+ * ended credential reads as `unauthenticated` whatever the status, and only
+ * a code this table does not know (or none, from a proxy or an older server)
+ * falls back to the status.
  */
 export type ReadFailureKind =
   "unauthenticated" | "refused" | "throttled" | "failed";
 
+/** Codes that say the credential itself is gone: sign in again. */
+const SESSION_ENDED_CODES: ReadonlySet<string> = new Set([
+  AUTH_ERROR_CODES.missing,
+  AUTH_ERROR_CODES.expired,
+  AUTH_ERROR_CODES.invalid,
+  DEFAULT_ERROR_CODES[401],
+  "auth.refresh.invalid",
+  "auth.refresh.reuse",
+  "auth.refresh.revoked",
+]);
+
+/** Codes that ask for a fresh proof on a session that is still good. */
+const PROOF_NEEDED_CODES: ReadonlySet<string> = new Set([
+  "auth.stepup.required",
+  REPROOF_REQUIRED_CODE,
+  "auth.reproof.failed",
+  "auth.reproof.too_weak",
+  AUTH_ERROR_CODES.mfaCode,
+]);
+
 export function readFailureKind(error: unknown): ReadFailureKind {
   if (error instanceof ApiError) {
+    const code = error.meta?.errorCode;
+    if (typeof code === "string") {
+      if (SESSION_ENDED_CODES.has(code)) return "unauthenticated";
+      if (PROOF_NEEDED_CODES.has(code)) return "failed";
+    }
     if (error.status === 401) return "unauthenticated";
     if (error.status === 403) return "refused";
     if (error.status === 429) return "throttled";

src/lib/openapi/error-codes.ts

@@ -1,4 +1,4 @@
-import { DEFAULT_ERROR_CODES } from "@/lib/api-response";
+import { DEFAULT_ERROR_CODES } from "@/lib/api/default-error-codes";
 
 /**
  * Every `meta.errorCode` the API emits, grouped by the surface that emits it.
@@ -412,6 +412,7 @@ export const ERROR_CODE_CATALOGUE: Readonly<Record<string, readonly string[]>> =
       "sharing.invite.invalid",
       "sharing.invite.invalid_scope",
       "sharing.invite.manage_browser_only",
+      "sharing.invite.no_account",
       "sharing.invite.refused",
       "sharing.invite.self",
       "sharing.not_permitted",

src/lib/openapi/routes/account-sharing.ts

@@ -945,7 +945,8 @@ export const accountSharingPaths: NonNullable<ZodOpenApiObject["paths"]> = {
           content: { "application/json": { schema: errorEnvelope } },
         },
         "404": {
-          description: "No account on this instance carries that identifier.",
+          description:
+            "No account on this instance carries that identifier (`meta.errorCode: sharing.invite.no_account`).",
           content: { "application/json": { schema: errorEnvelope } },
         },
         "409": {
@@ -1099,7 +1100,7 @@ export const accountSharingPaths: NonNullable<ZodOpenApiObject["paths"]> = {
         },
         "429": {
           description:
-            "More than ten profiles from one caller within the hour. No error code — rate-limit refusals carry none anywhere in this API; branch on the status. Nothing was created.",
+            "More than ten profiles from one caller within the hour (`meta.errorCode: http.rate_limited`, the status default; a 429 has one meaning here, so the status alone is enough to branch on). Nothing was created.",
           content: { "application/json": { schema: errorEnvelope } },
         },
       },
@@ -1167,7 +1168,7 @@ export const accountSharingPaths: NonNullable<ZodOpenApiObject["paths"]> = {
         },
         "429": {
           description:
-            "More than ten edits from one caller within the hour — the ceiling creation carries. No error code; branch on the status. Nothing was changed, and the refusal lands before the record named in the path is looked at.",
+            "More than ten edits from one caller within the hour — the ceiling creation carries. `meta.errorCode: http.rate_limited`, the status default. Nothing was changed, and the refusal lands before the record named in the path is looked at.",
           content: { "application/json": { schema: errorEnvelope } },
         },
       },
@@ -1239,7 +1240,7 @@ export const accountSharingPaths: NonNullable<ZodOpenApiObject["paths"]> = {
       tags: ["Account sharing"],
       summary: "Invite another Guardian",
       description:
-        "Offers somebody else a share in looking after this profile, at MANAGE over the whole record. Cookie-only and step-up gated, like every act in this family — the read beside it is not. **Resolve refusals on `meta.errorCode` first and fall back to the status only for the two arms that carry none**, because this route answers 404 twice and the codeless one is the less serious of the two: an identifier that matches no account carries no code, while `managed_profile.not_found` means the caller is not a Guardian of that profile at all. A client branching on the status first would tell somebody to check a spelling when the real answer is that the record is no longer theirs to administer.",
+        "Offers somebody else a share in looking after this profile, at MANAGE over the whole record. Cookie-only and step-up gated, like every act in this family — the read beside it is not. **Resolve refusals on `meta.errorCode`, not on the status**, because this route answers 404 twice and the two need different next steps: `sharing.invite.no_account` means no account carries that identifier, while `managed_profile.not_found` means the caller is not a Guardian of that profile at all. A client branching on the status would tell somebody to check a spelling when the real answer is that the record is no longer theirs to administer.",
       requestParams: {
         path: z.object({ id: z.string() }),
       },
@@ -1272,7 +1273,7 @@ export const accountSharingPaths: NonNullable<ZodOpenApiObject["paths"]> = {
         },
         "404": {
           description:
-            "Two refusals share this status and only one carries a code. **No `meta.errorCode`**: no account on this instance carries that identifier — the same deliberate disclosure to an authenticated caller that `POST /api/account/grants` makes, and codeless there too, so this family does not answer one way here and another way one page over. `meta.errorCode: managed_profile.not_found`: no such managed profile, or the caller is not one of its Guardians.",
+            "Two refusals share this status, each with its own code. `meta.errorCode: sharing.invite.no_account`: no account on this instance carries that identifier — the same deliberate disclosure to an authenticated caller that `POST /api/account/grants` makes, with the same code, so this family does not answer one way here and another way one page over. `meta.errorCode: managed_profile.not_found`: no such managed profile, or the caller is not one of its Guardians.",
           content: { "application/json": { schema: errorEnvelope } },
         },
         "409": {
@@ -1287,7 +1288,7 @@ export const accountSharingPaths: NonNullable<ZodOpenApiObject["paths"]> = {
         },
         "429": {
           description:
-            "More than ten invitations from one caller within the hour. No error code, as above; branch on the status.",
+            "More than ten invitations from one caller within the hour (`meta.errorCode: http.rate_limited`, the status default).",
           content: { "application/json": { schema: errorEnvelope } },
         },
       },

src/lib/openapi/routes/auth.ts

@@ -2158,7 +2158,7 @@ export const authPaths: NonNullable<ZodOpenApiObject["paths"]> = {
         },
         "403": {
           description:
-            "The operator has switched the API off instance-wide (`AppSettings.apiGlobal`). No `meta.errorCode`; nothing was revoked. The sibling list is deliberately not gated this way — a token stays live while the switch is off, so its owner can still see it here even though this call will not kill it.",
+            "The operator has switched the API off instance-wide (`AppSettings.apiGlobal`). `meta.errorCode` is the status default `http.forbidden`; nothing was revoked. The sibling list is deliberately not gated this way — a token stays live while the switch is off, so its owner can still see it here even though this call will not kill it.",
           content: { "application/json": { schema: errorEnvelope } },
         },
         "404": {

src/lib/openapi/routes/profile.ts

@@ -1426,7 +1426,7 @@ export const profilePaths: NonNullable<ZodOpenApiObject["paths"]> = {
         // quietly omits the refusal a person actually hits.
         "422": {
           description:
-            "The write was refused and nothing was stored. `meta.errorCode` distinguishes the cases: `health_score_config.too_narrow` — the selection cannot produce a score (`meta.reason` is `no_pillars_selected`, and the `error` string is the sentence to show the person). Since v1.38 the empty selection is the ONLY one refused: two areas of health, or one, now save and produce a score that labels its own breadth, so a client must not pre-empt the write with a three-area rule of its own. `health_score_config.invalid` — the body failed validation, with the per-issue list under `details.issues`; `invalid_base_updated_at` — `baseUpdatedAt` was present but unparseable, `null` included, which is rejected rather than falling back to the unconditional write. A body that is not JSON at all returns the bare message `health-score-config.body.invalid_json` with no errorCode.",
+            "The write was refused and nothing was stored. `meta.errorCode` distinguishes the cases: `health_score_config.too_narrow` — the selection cannot produce a score (`meta.reason` is `no_pillars_selected`, and the `error` string is the sentence to show the person). Since v1.38 the empty selection is the ONLY one refused: two areas of health, or one, now save and produce a score that labels its own breadth, so a client must not pre-empt the write with a three-area rule of its own. `health_score_config.invalid` — the body failed validation, with the per-issue list under `details.issues`; `invalid_base_updated_at` — `baseUpdatedAt` was present but unparseable, `null` included, which is rejected rather than falling back to the unconditional write. A body that is not JSON at all returns the bare message `health-score-config.body.invalid_json` with the status default `meta.errorCode: http.invalid`.",
           content: { "application/json": { schema: errorEnvelope } },
         },
       },

src/lib/sharing/grant-view.ts

@@ -112,3 +112,10 @@ export function toGrantView(
     revokedBy: grant.revokedBy,
   };
 }
+
+/**
+ * The 404 both invitation routes answer when no account carries the typed
+ * name or e-mail. Its own code, because each route has a second 404 that
+ * needs a different next step.
+ */
+export const INVITE_NO_ACCOUNT_CODE = "sharing.invite.no_account";