diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0a520e6..a81d5d4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Routing eval (GW-049): optional `contribution_mode` on outcomes, additive eval `ground_truth.routing`, reconstructed routing corpus kept out of frozen headline accuracy, `false_build_occupied` stays 0 for definitive ownership.
 - Local watch registry (GW-048): `gitworthy watch add|list|show|recheck|remove` and MCP `watch_*`. Fingerprint recheck reports exact deltas. No auto-create from WATCH routes and no GitHub writes.
 - Contribution routing v2 (GW-043–047): `worth_check` can attach a `routing` decision; `gitworthy portfolio` / MCP `portfolio` ranks issue+PR opportunities by contribution mode with separate `dispatch_state`; `gitworthy prs` / MCP `pr_scan` is a bounded two-stage PR inventory. Verdict policy is unchanged. Hermes `contribution_profile` examples stay in docs, not global defaults. Org portfolio fans out PR scans to at most 5 hunt repos (inventory ≤25, enrich ≤5). Advisory `failed_checks` do not demote BUILD.
 - Agent Plugins v1.0.0 packaging: `plugin.json`, `mcp.json`, canonical `skills/gitworthy/SKILL.md`, CI sync check (`pnpm agent-plugins:check`).
diff --git a/docs/EVALS.md b/docs/EVALS.md
index 98ef7e6..6a06a50 100644
--- a/docs/EVALS.md
+++ b/docs/EVALS.md
@@ -11,6 +11,7 @@ Full detail: [`../eval/README.md`](../eval/README.md), [`../eval/METRICS.md`](..
 | **frozen** | Offline fixture replay | Yes |
 | **live** | Public GitHub/npm/git | Advisory |
 | **private** | Local captures (gitignored) | No |
+| **reconstructed routing** | In-process `routeContribution` fixtures | Advisory; never mixed into frozen headline accuracy |
 
 ```sh
 pnpm eval:frozen
diff --git a/eval/reconstructed/README.md b/eval/reconstructed/README.md
new file mode 100644
index 0000000..39a8808
--- /dev/null
+++ b/eval/reconstructed/README.md
@@ -0,0 +1,8 @@
+# Reconstructed routing eval
+
+This partition is **not** snapshot-backed frozen eval.
+
+- Cases live in `src/core/routing-eval-cases.ts`.
+- Headline accuracy (`mode_top1_accuracy`) uses only `partition: snapshot` cases.
+- Reconstructed / research cases never mix into frozen-suite accuracy.
+- `false_build_occupied` must stay `0` for definitive-ownership fixtures.
diff --git a/schemas/gitworthy-eval-case-catalog.v1.schema.json b/schemas/gitworthy-eval-case-catalog.v1.schema.json
index 087b779..fd53f7d 100644
--- a/schemas/gitworthy-eval-case-catalog.v1.schema.json
+++ b/schemas/gitworthy-eval-case-catalog.v1.schema.json
@@ -185,6 +185,72 @@
                   "type": "string",
                   "minLength": 1
                 }
+              },
+              "routing": {
+                "type": "object",
+                "properties": {
+                  "primary_mode": {
+                    "type": "string",
+                    "enum": [
+                      "BUILD",
+                      "REVIEW",
+                      "SALVAGE",
+                      "REPRODUCE",
+                      "EVAL",
+                      "DOC",
+                      "WATCH",
+                      "PASS"
+                    ]
+                  },
+                  "acceptable_modes": {
+                    "default": [],
+                    "type": "array",
+                    "items": {
+                      "type": "string",
+                      "enum": [
+                        "BUILD",
+                        "REVIEW",
+                        "SALVAGE",
+                        "REPRODUCE",
+                        "EVAL",
+                        "DOC",
+                        "WATCH",
+                        "PASS"
+                      ]
+                    }
+                  },
+                  "forbidden_modes": {
+                    "default": [],
+                    "type": "array",
+                    "items": {
+                      "type": "string",
+                      "enum": [
+                        "BUILD",
+                        "REVIEW",
+                        "SALVAGE",
+                        "REPRODUCE",
+                        "EVAL",
+                        "DOC",
+                        "WATCH",
+                        "PASS"
+                      ]
+                    }
+                  },
+                  "build_contention": {
+                    "type": "string",
+                    "enum": [
+                      "GREEN",
+                      "YELLOW",
+                      "RED"
+                    ]
+                  }
+                },
+                "required": [
+                  "primary_mode",
+                  "acceptable_modes",
+                  "forbidden_modes"
+                ],
+                "additionalProperties": false
               }
             },
             "required": [
diff --git a/schemas/gitworthy-eval-case.v1.schema.json b/schemas/gitworthy-eval-case.v1.schema.json
index 5a6b281..b2c19db 100644
--- a/schemas/gitworthy-eval-case.v1.schema.json
+++ b/schemas/gitworthy-eval-case.v1.schema.json
@@ -162,6 +162,72 @@
             "type": "string",
             "minLength": 1
           }
+        },
+        "routing": {
+          "type": "object",
+          "properties": {
+            "primary_mode": {
+              "type": "string",
+              "enum": [
+                "BUILD",
+                "REVIEW",
+                "SALVAGE",
+                "REPRODUCE",
+                "EVAL",
+                "DOC",
+                "WATCH",
+                "PASS"
+              ]
+            },
+            "acceptable_modes": {
+              "default": [],
+              "type": "array",
+              "items": {
+                "type": "string",
+                "enum": [
+                  "BUILD",
+                  "REVIEW",
+                  "SALVAGE",
+                  "REPRODUCE",
+                  "EVAL",
+                  "DOC",
+                  "WATCH",
+                  "PASS"
+                ]
+              }
+            },
+            "forbidden_modes": {
+              "default": [],
+              "type": "array",
+              "items": {
+                "type": "string",
+                "enum": [
+                  "BUILD",
+                  "REVIEW",
+                  "SALVAGE",
+                  "REPRODUCE",
+                  "EVAL",
+                  "DOC",
+                  "WATCH",
+                  "PASS"
+                ]
+              }
+            },
+            "build_contention": {
+              "type": "string",
+              "enum": [
+                "GREEN",
+                "YELLOW",
+                "RED"
+              ]
+            }
+          },
+          "required": [
+            "primary_mode",
+            "acceptable_modes",
+            "forbidden_modes"
+          ],
+          "additionalProperties": false
         }
       },
       "required": [
diff --git a/schemas/gitworthy-outcome-event.v1.schema.json b/schemas/gitworthy-outcome-event.v1.schema.json
index 9e76c3b..d7309a0 100644
--- a/schemas/gitworthy-outcome-event.v1.schema.json
+++ b/schemas/gitworthy-outcome-event.v1.schema.json
@@ -93,6 +93,31 @@
     "pr_url": {
       "type": "string",
       "format": "uri"
+    },
+    "contribution_mode": {
+      "type": "string",
+      "enum": [
+        "BUILD",
+        "REVIEW",
+        "SALVAGE",
+        "REPRODUCE",
+        "EVAL",
+        "DOC",
+        "WATCH",
+        "PASS"
+      ]
+    },
+    "investigation_class": {
+      "type": "string",
+      "enum": [
+        "repro",
+        "ci_triage",
+        "history",
+        "review",
+        "salvage",
+        "docs",
+        "eval"
+      ]
     }
   },
   "required": [
diff --git a/schemas/gitworthy-routing-eval-metrics.v1.schema.json b/schemas/gitworthy-routing-eval-metrics.v1.schema.json
new file mode 100644
index 0000000..b3a94ba
--- /dev/null
+++ b/schemas/gitworthy-routing-eval-metrics.v1.schema.json
@@ -0,0 +1,112 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "type": "object",
+  "properties": {
+    "routing_cases": {
+      "type": "integer",
+      "minimum": 0,
+      "maximum": 9007199254740991
+    },
+    "snapshot_cases": {
+      "type": "integer",
+      "minimum": 0,
+      "maximum": 9007199254740991
+    },
+    "reconstructed_cases": {
+      "type": "integer",
+      "minimum": 0,
+      "maximum": 9007199254740991
+    },
+    "mode_top1_accuracy": {
+      "anyOf": [
+        {
+          "type": "number",
+          "minimum": 0,
+          "maximum": 1
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "acceptable_mode_accuracy": {
+      "anyOf": [
+        {
+          "type": "number",
+          "minimum": 0,
+          "maximum": 1
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "false_build_occupied": {
+      "type": "integer",
+      "minimum": 0,
+      "maximum": 9007199254740991
+    },
+    "false_build_blocked": {
+      "type": "integer",
+      "minimum": 0,
+      "maximum": 9007199254740991
+    },
+    "false_pass_actionable": {
+      "type": "integer",
+      "minimum": 0,
+      "maximum": 9007199254740991
+    },
+    "counts_by_mode": {
+      "type": "object",
+      "propertyNames": {
+        "type": "string"
+      },
+      "additionalProperties": {
+        "type": "integer",
+        "minimum": 0,
+        "maximum": 9007199254740991
+      }
+    },
+    "counts_by_contention": {
+      "type": "object",
+      "propertyNames": {
+        "type": "string"
+      },
+      "additionalProperties": {
+        "type": "integer",
+        "minimum": 0,
+        "maximum": 9007199254740991
+      }
+    },
+    "counts_by_confidence": {
+      "type": "object",
+      "propertyNames": {
+        "type": "string"
+      },
+      "additionalProperties": {
+        "type": "integer",
+        "minimum": 0,
+        "maximum": 9007199254740991
+      }
+    },
+    "headline_excludes_reconstructed": {
+      "type": "boolean",
+      "const": true
+    }
+  },
+  "required": [
+    "routing_cases",
+    "snapshot_cases",
+    "reconstructed_cases",
+    "mode_top1_accuracy",
+    "acceptable_mode_accuracy",
+    "false_build_occupied",
+    "false_build_blocked",
+    "false_pass_actionable",
+    "counts_by_mode",
+    "counts_by_contention",
+    "counts_by_confidence",
+    "headline_excludes_reconstructed"
+  ],
+  "additionalProperties": false
+}
diff --git a/scripts/generate-schemas.ts b/scripts/generate-schemas.ts
index 9747045..ff9dd6c 100644
--- a/scripts/generate-schemas.ts
+++ b/scripts/generate-schemas.ts
@@ -22,6 +22,7 @@ import { PortfolioItemSchema } from '../src/contracts/portfolio.js';
 import { PrScanResultSchema } from '../src/contracts/pr-scan.js';
 import { OpportunityTargetSchema } from '../src/contracts/opportunities.js';
 import { ContributionProfileSchema } from '../src/contracts/contribution-profile.js';
+import { RoutingEvalMetricsSchema } from '../src/contracts/routing-eval.js';
 import {
   TrackOCovariatesRecordSchema,
   TrackOContingencyTableSchema,
@@ -61,6 +62,7 @@ const docs: Array<{ file: string; schema: z.ZodType }> = [
   { file: 'gitworthy-pr-scan.v1.schema.json', schema: PrScanResultSchema },
   { file: 'gitworthy-portfolio-item.v1.schema.json', schema: PortfolioItemSchema },
   { file: 'gitworthy-contribution-profile.v1.schema.json', schema: ContributionProfileSchema },
+  { file: 'gitworthy-routing-eval-metrics.v1.schema.json', schema: RoutingEvalMetricsSchema },
   { file: 'gitworthy-track-o-join-key.v1.schema.json', schema: TrackOJoinKeySchema },
   { file: 'gitworthy-track-o-covariates.v1.schema.json', schema: TrackOCovariatesRecordSchema },
   { file: 'gitworthy-track-o-contingency.v1.schema.json', schema: TrackOContingencyTableSchema }
diff --git a/src/contracts/eval.ts b/src/contracts/eval.ts
index 8519c9a..bd63058 100644
--- a/src/contracts/eval.ts
+++ b/src/contracts/eval.ts
@@ -1,5 +1,6 @@
 import { z } from 'zod';
 import { DispositionSchema, SCHEMA_VERSION, SchemaVersionSchema, VerdictSchema } from './common.js';
+import { BuildContentionSchema, ContributionModeSchema } from './routing.js';
 
 /** Case/adjudication contract shared by frozen, live, and private eval suites (GW-021). */
 export const EVAL_CASE_VERSION = 1 as const;
@@ -35,7 +36,13 @@ export const EvalGroundTruthSchema = z.object({
   required_findings: z.array(z.string().min(1)).default([]),
   forbidden_findings: z.array(z.string().min(1)).default([]),
   required_signals: z.array(z.string().min(1)).default([]),
-  forbidden_signals: z.array(z.string().min(1)).default([])
+  forbidden_signals: z.array(z.string().min(1)).default([]),
+  routing: z.object({
+    primary_mode: ContributionModeSchema,
+    acceptable_modes: z.array(ContributionModeSchema).default([]),
+    forbidden_modes: z.array(ContributionModeSchema).default([]),
+    build_contention: BuildContentionSchema.optional()
+  }).strict().optional()
 }).strict();
 
 export const EvalCaseClassificationSchema = z.enum([
diff --git a/src/contracts/outcomes.ts b/src/contracts/outcomes.ts
index 529827e..c8e373f 100644
--- a/src/contracts/outcomes.ts
+++ b/src/contracts/outcomes.ts
@@ -1,4 +1,5 @@
 import { z } from 'zod';
+import { ContributionModeSchema } from './routing.js';
 
 /** Outcome event schema for the local durable store (Track O T1 labels map onto these events). */
 export const OutcomeEventNameSchema = z.enum([
@@ -46,7 +47,18 @@ export const OutcomeEventSchema = z.object({
   /** True when the contribution proceeded despite a soft SKIP (Track O anti-SKIP policy). */
   acted_against_skip: z.boolean().optional(),
   /** PR URL once known; join key companion to decision_id. */
-  pr_url: z.string().url().optional()
+  pr_url: z.string().url().optional(),
+  /** Optional routing annotation. Legacy outcomes without this still parse. */
+  contribution_mode: ContributionModeSchema.optional(),
+  investigation_class: z.enum([
+    'repro',
+    'ci_triage',
+    'history',
+    'review',
+    'salvage',
+    'docs',
+    'eval'
+  ]).optional()
 }).strict().superRefine((value, ctx) => {
   if (value.close_reason !== undefined && value.event !== 'closed_unmerged') {
     ctx.addIssue({
diff --git a/src/contracts/routing-eval.ts b/src/contracts/routing-eval.ts
new file mode 100644
index 0000000..74dc905
--- /dev/null
+++ b/src/contracts/routing-eval.ts
@@ -0,0 +1,44 @@
+import { z } from 'zod';
+import { BuildContentionSchema, ContributionModeSchema } from './routing.js';
+
+export const DecisionAccelerationSchema = z.object({
+  from_mode: ContributionModeSchema,
+  to_mode: ContributionModeSchema,
+  hours_saved: z.number().nonnegative(),
+  reason: z.string().min(1)
+}).strict();
+
+export const RoutingEvalPartitionSchema = z.enum(['snapshot', 'reconstructed']);
+
+export const RoutingEvalCaseSchema = z.object({
+  id: z.string().min(1),
+  name: z.string().min(1),
+  partition: RoutingEvalPartitionSchema,
+  adversarial: z.boolean().default(false),
+  facts: z.record(z.string(), z.unknown()),
+  expected: z.object({
+    primary_mode: ContributionModeSchema,
+    acceptable_modes: z.array(ContributionModeSchema).default([]),
+    forbidden_modes: z.array(ContributionModeSchema).default([]),
+    build_contention: BuildContentionSchema.optional()
+  }).strict()
+}).strict();
+
+export const RoutingEvalMetricsSchema = z.object({
+  routing_cases: z.number().int().nonnegative(),
+  snapshot_cases: z.number().int().nonnegative(),
+  reconstructed_cases: z.number().int().nonnegative(),
+  mode_top1_accuracy: z.number().min(0).max(1).nullable(),
+  acceptable_mode_accuracy: z.number().min(0).max(1).nullable(),
+  false_build_occupied: z.number().int().nonnegative(),
+  false_build_blocked: z.number().int().nonnegative(),
+  false_pass_actionable: z.number().int().nonnegative(),
+  counts_by_mode: z.record(z.string(), z.number().int().nonnegative()),
+  counts_by_contention: z.record(z.string(), z.number().int().nonnegative()),
+  counts_by_confidence: z.record(z.string(), z.number().int().nonnegative()),
+  headline_excludes_reconstructed: z.literal(true)
+}).strict();
+
+export type DecisionAcceleration = z.infer<typeof DecisionAccelerationSchema>;
+export type RoutingEvalCase = z.infer<typeof RoutingEvalCaseSchema>;
+export type RoutingEvalMetrics = z.infer<typeof RoutingEvalMetricsSchema>;
diff --git a/src/core/index.ts b/src/core/index.ts
index 1a924af..a3691ae 100644
--- a/src/core/index.ts
+++ b/src/core/index.ts
@@ -41,3 +41,4 @@ export type { ProbeTemplate, ProbeTemplateId } from './probe-templates.js';
 export { parseSkillProfile, resolveSkillProfile, scoreSkillFit } from './skill-fit.js';
 export type { SkillProfile } from './skill-fit.js';
 export { routeContribution, scoreEvidenceability } from '../decision/contribution-route.js';
+export { runReconstructedRoutingEval, scoreRoutingCases } from './routing-eval.js';
diff --git a/src/core/portfolio.ts b/src/core/portfolio.ts
index 6dcb0ee..2f6a6fd 100644
--- a/src/core/portfolio.ts
+++ b/src/core/portfolio.ts
@@ -105,7 +105,7 @@ export function computeCapacity(
     const lastActive = [...ordered].reverse().find((event) => ACTIVE_EVENTS.has(event.event));
     if (!lastActive) continue;
     if (lastTerminal && lastTerminal.occurred_at >= lastActive.occurred_at) continue;
-    const modeRaw = lastActive.data.contribution_mode;
+    const modeRaw = lastActive.contribution_mode ?? lastActive.data.contribution_mode;
     const mode = typeof modeRaw === 'string' ? modeRaw : 'BUILD';
     if (typeof modeRaw !== 'string') {
       missingMode += 1;
diff --git a/src/core/routing-eval-cases.ts b/src/core/routing-eval-cases.ts
new file mode 100644
index 0000000..d2bc50f
--- /dev/null
+++ b/src/core/routing-eval-cases.ts
@@ -0,0 +1,212 @@
+import type { RoutingEvalCase } from '../contracts/routing-eval.js';
+import type { RouteFacts } from '../contracts/routing.js';
+
+const complete = {
+  mandatory_checks_complete: true,
+  failed_checks: [] as string[],
+  skipped_checks: [] as string[],
+  budget_truncated: false,
+  rate_limit_degraded: false,
+  advisory_missing: [] as string[]
+};
+
+function facts(partial: Partial<RouteFacts> & Pick<RouteFacts, 'verdict' | 'disposition' | 'linked'>): RouteFacts {
+  return {
+    findings: [],
+    mandatoryFailures: [],
+    coverage: complete,
+    ...partial
+  };
+}
+
+const reconstructedRoutingCaseDrafts: Array<Omit<RoutingEvalCase, 'adversarial'> & { adversarial?: boolean }> = [
+  {
+    id: 'recon-unoccupied-bug-build',
+    name: 'Unoccupied clear bug → BUILD',
+    partition: 'reconstructed',
+    facts: facts({
+      verdict: 'ACT',
+      disposition: 'greenfield',
+      quality: { looksLikeBug: true, repro: 'present', softAsk: false },
+      linked: { activeClosers: 0, activeRelatedPrs: 0, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: false, claimRequired: false }
+    }),
+    expected: { primary_mode: 'BUILD', acceptable_modes: [], forbidden_modes: ['PASS'] }
+  },
+  {
+    id: 'recon-missing-repro',
+    name: 'Missing repro → REPRODUCE',
+    partition: 'reconstructed',
+    facts: facts({
+      verdict: 'VERIFY',
+      disposition: 'greenfield',
+      quality: { looksLikeBug: true, repro: 'missing', softAsk: false },
+      linked: { activeClosers: 0, activeRelatedPrs: 0, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: false, claimRequired: false }
+    }),
+    expected: { primary_mode: 'REPRODUCE', acceptable_modes: ['WATCH'], forbidden_modes: ['BUILD'] }
+  },
+  {
+    id: 'recon-explicit-closer',
+    name: 'Explicit closer → REVIEW',
+    partition: 'reconstructed',
+    facts: facts({
+      verdict: 'SKIP',
+      disposition: 'land_only',
+      findings: [{ id: '1', type: 'linked_pr_open', strength: 'definitive', effect: 'block', source: 'test', message: 'closer', data: {} }],
+      linked: { activeClosers: 1, activeRelatedPrs: 1, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: false, claimRequired: false, healthyActiveCloser: false }
+    }),
+    expected: { primary_mode: 'REVIEW', acceptable_modes: ['WATCH'], forbidden_modes: ['BUILD'] }
+  },
+  {
+    id: 'recon-multiple-closers',
+    name: 'Multiple closers → REVIEW',
+    partition: 'reconstructed',
+    facts: facts({
+      verdict: 'SKIP',
+      disposition: 'land_only',
+      findings: [{ id: '1', type: 'linked_pr_open', strength: 'definitive', effect: 'block', source: 'test', message: 'closer', data: {} }],
+      linked: { activeClosers: 2, activeRelatedPrs: 2, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: false, claimRequired: false }
+    }),
+    expected: { primary_mode: 'REVIEW', acceptable_modes: [], forbidden_modes: ['BUILD'] }
+  },
+  {
+    id: 'recon-healthy-active-pr',
+    name: 'Healthy active PR → WATCH',
+    partition: 'reconstructed',
+    facts: facts({
+      verdict: 'SKIP',
+      disposition: 'land_only',
+      findings: [{ id: '1', type: 'linked_pr_open', strength: 'definitive', effect: 'block', source: 'test', message: 'closer', data: {} }],
+      linked: { activeClosers: 1, activeRelatedPrs: 1, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: false, claimRequired: false, healthyActiveCloser: true }
+    }),
+    expected: { primary_mode: 'WATCH', acceptable_modes: ['REVIEW'], forbidden_modes: ['BUILD'] }
+  },
+  {
+    id: 'recon-closed-unmerged',
+    name: 'Closed unmerged credible → SALVAGE or REVIEW',
+    partition: 'reconstructed',
+    facts: facts({
+      verdict: 'VERIFY',
+      disposition: 'review',
+      linked: {
+        activeClosers: 0, activeRelatedPrs: 0, closedUnmergedAttempts: 1, mergedClosers: 0,
+        assigned: false, claimRequired: false, issueOpen: true, substantivePriorAttempt: true
+      }
+    }),
+    expected: { primary_mode: 'SALVAGE', acceptable_modes: ['REVIEW'], forbidden_modes: [] }
+  },
+  {
+    id: 'recon-claim-required',
+    name: 'Claim required → WATCH',
+    partition: 'reconstructed',
+    facts: facts({
+      verdict: 'VERIFY',
+      disposition: 'claim_first',
+      linked: { activeClosers: 0, activeRelatedPrs: 0, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: false, claimRequired: true }
+    }),
+    expected: { primary_mode: 'WATCH', acceptable_modes: [], forbidden_modes: ['BUILD'] }
+  },
+  {
+    id: 'recon-assigned',
+    name: 'Assigned → WATCH',
+    partition: 'reconstructed',
+    facts: facts({
+      verdict: 'VERIFY',
+      disposition: 'greenfield',
+      linked: { activeClosers: 0, activeRelatedPrs: 0, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: true, claimRequired: false }
+    }),
+    expected: { primary_mode: 'WATCH', acceptable_modes: [], forbidden_modes: ['BUILD'] }
+  },
+  {
+    id: 'recon-released-fix',
+    name: 'Released fix → PASS',
+    partition: 'reconstructed',
+    facts: facts({
+      verdict: 'SKIP',
+      disposition: 'blocked',
+      findings: [{ id: '1', type: 'released_fix', strength: 'definitive', effect: 'block', source: 'test', message: 'released', data: {} }],
+      linked: { activeClosers: 0, activeRelatedPrs: 0, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: false, claimRequired: false }
+    }),
+    expected: { primary_mode: 'PASS', acceptable_modes: [], forbidden_modes: ['BUILD'] }
+  },
+  {
+    id: 'recon-no-pr-path',
+    name: 'No PR path → PASS',
+    partition: 'reconstructed',
+    facts: facts({
+      verdict: 'SKIP',
+      disposition: 'blocked',
+      findings: [{ id: '1', type: 'no_pr_path', strength: 'definitive', effect: 'block', source: 'test', message: 'no pr', data: {} }],
+      linked: { activeClosers: 0, activeRelatedPrs: 0, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: false, claimRequired: false }
+    }),
+    expected: { primary_mode: 'PASS', acceptable_modes: [], forbidden_modes: ['BUILD'] }
+  },
+  {
+    id: 'recon-docs-only',
+    name: 'Docs-only → DOC',
+    partition: 'reconstructed',
+    facts: facts({
+      verdict: 'ACT',
+      disposition: 'greenfield',
+      categoryHints: { documentation: true, evaluation: false },
+      linked: { activeClosers: 0, activeRelatedPrs: 0, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: false, claimRequired: false }
+    }),
+    expected: { primary_mode: 'DOC', acceptable_modes: ['BUILD'], forbidden_modes: [] }
+  },
+  {
+    id: 'recon-provider-failure',
+    name: 'Provider failure → low-confidence non-BUILD',
+    partition: 'reconstructed',
+    facts: facts({
+      verdict: 'VERIFY',
+      disposition: 'greenfield',
+      coverage: { ...complete, mandatory_checks_complete: false, failed_checks: ['linked_work'] },
+      linked: { activeClosers: 0, activeRelatedPrs: 0, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: false, claimRequired: false }
+    }),
+    expected: { primary_mode: 'WATCH', acceptable_modes: ['REVIEW', 'REPRODUCE', 'PASS'], forbidden_modes: ['BUILD'] }
+  },
+  {
+    id: 'adv-closer-provider-error',
+    name: 'Closer + provider error still forbids BUILD',
+    partition: 'reconstructed',
+    adversarial: true,
+    facts: facts({
+      verdict: 'VERIFY',
+      disposition: 'land_only',
+      findings: [{ id: '1', type: 'linked_pr_open', strength: 'definitive', effect: 'block', source: 'test', message: 'closer', data: {} }],
+      coverage: { ...complete, mandatory_checks_complete: false, failed_checks: ['issue_vs_main'] },
+      linked: { activeClosers: 1, activeRelatedPrs: 1, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: false, claimRequired: false }
+    }),
+    expected: { primary_mode: 'REVIEW', acceptable_modes: ['WATCH'], forbidden_modes: ['BUILD'] }
+  },
+  {
+    id: 'adv-title-overlap-only',
+    name: 'Heuristic title overlap only cannot own the issue',
+    partition: 'reconstructed',
+    adversarial: true,
+    facts: facts({
+      verdict: 'VERIFY',
+      disposition: 'crowded',
+      findings: [{ id: '1', type: 'title_overlap_pr', strength: 'heuristic', effect: 'verify', source: 'test', message: 'overlap', data: {} }],
+      linked: { activeClosers: 0, activeRelatedPrs: 1, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: false, claimRequired: false }
+    }),
+    expected: { primary_mode: 'REVIEW', acceptable_modes: ['WATCH', 'REPRODUCE'], forbidden_modes: [] }
+  },
+  {
+    id: 'adv-assigned-plus-closer',
+    name: 'Assigned + explicit closer still forbids BUILD',
+    partition: 'reconstructed',
+    adversarial: true,
+    facts: facts({
+      verdict: 'SKIP',
+      disposition: 'land_only',
+      findings: [{ id: '1', type: 'linked_pr_open', strength: 'definitive', effect: 'block', source: 'test', message: 'closer', data: {} }],
+      linked: { activeClosers: 1, activeRelatedPrs: 1, closedUnmergedAttempts: 0, mergedClosers: 0, assigned: true, claimRequired: false }
+    }),
+    expected: { primary_mode: 'REVIEW', acceptable_modes: ['WATCH'], forbidden_modes: ['BUILD'] }
+  }
+];
+
+export const reconstructedRoutingCases: RoutingEvalCase[] = reconstructedRoutingCaseDrafts.map((item) => ({
+  adversarial: false,
+  ...item
+}));
diff --git a/src/core/routing-eval.ts b/src/core/routing-eval.ts
new file mode 100644
index 0000000..8eb0898
--- /dev/null
+++ b/src/core/routing-eval.ts
@@ -0,0 +1,72 @@
+import type { RouteFacts, ContributionMode } from '../contracts/routing.js';
+import { routeContribution } from '../decision/contribution-route.js';
+import {
+  RoutingEvalMetricsSchema,
+  type RoutingEvalCase,
+  type RoutingEvalMetrics
+} from '../contracts/routing-eval.js';
+import { reconstructedRoutingCases } from './routing-eval-cases.js';
+
+function asFacts(value: Record<string, unknown>): RouteFacts {
+  return value as unknown as RouteFacts;
+}
+
+export function scoreRoutingCases(cases: RoutingEvalCase[]): RoutingEvalMetrics {
+  let top1 = 0;
+  let acceptable = 0;
+  let falseBuildOccupied = 0;
+  let falseBuildBlocked = 0;
+  let falsePassActionable = 0;
+  const counts_by_mode: Record<string, number> = {};
+  const counts_by_contention: Record<string, number> = {};
+  const counts_by_confidence: Record<string, number> = {};
+  const snapshot = cases.filter((item) => item.partition === 'snapshot');
+  const reconstructed = cases.filter((item) => item.partition === 'reconstructed');
+  const headline = snapshot.length > 0 ? snapshot : [];
+
+  for (const item of cases) {
+    const decision = routeContribution(asFacts(item.facts));
+    counts_by_mode[decision.primary_mode] = (counts_by_mode[decision.primary_mode] ?? 0) + 1;
+    counts_by_contention[decision.build_contention] = (counts_by_contention[decision.build_contention] ?? 0) + 1;
+    counts_by_confidence[decision.confidence] = (counts_by_confidence[decision.confidence] ?? 0) + 1;
+    const okTop = decision.primary_mode === item.expected.primary_mode;
+    const okAccept = okTop || item.expected.acceptable_modes.includes(decision.primary_mode);
+    if (item.partition === 'snapshot') {
+      if (okTop) top1 += 1;
+      if (okAccept) acceptable += 1;
+    }
+    if (item.expected.forbidden_modes.includes('BUILD') && decision.primary_mode === 'BUILD') {
+      falseBuildOccupied += 1;
+    }
+    if (item.expected.primary_mode === 'BUILD' && decision.primary_mode !== 'BUILD' && !item.expected.acceptable_modes.includes(decision.primary_mode)) {
+      falseBuildBlocked += 1;
+    }
+    if (item.expected.forbidden_modes.includes('PASS') && decision.primary_mode === 'PASS') {
+      falsePassActionable += 1;
+    }
+  }
+
+  const headlineCount = headline.length;
+  return RoutingEvalMetricsSchema.parse({
+    routing_cases: cases.length,
+    snapshot_cases: snapshot.length,
+    reconstructed_cases: reconstructed.length,
+    mode_top1_accuracy: headlineCount === 0 ? null : top1 / headlineCount,
+    acceptable_mode_accuracy: headlineCount === 0 ? null : acceptable / headlineCount,
+    false_build_occupied: falseBuildOccupied,
+    false_build_blocked: falseBuildBlocked,
+    false_pass_actionable: falsePassActionable,
+    counts_by_mode,
+    counts_by_contention,
+    counts_by_confidence,
+    headline_excludes_reconstructed: true
+  });
+}
+
+export function runReconstructedRoutingEval(): RoutingEvalMetrics {
+  return scoreRoutingCases(reconstructedRoutingCases);
+}
+
+export function coverageHasMode(mode: ContributionMode): boolean {
+  return reconstructedRoutingCases.some((item) => item.expected.primary_mode === mode);
+}
diff --git a/test/portfolio.test.ts b/test/portfolio.test.ts
index 6f9c415..0155dbe 100644
--- a/test/portfolio.test.ts
+++ b/test/portfolio.test.ts
@@ -79,8 +79,8 @@ describe('portfolio capacity and dispatch', () => {
         fetched_at: '2026-08-01T00:00:00.000Z'
       }),
       listOutcomes: async () => [
-        outcome({ event: 'selected', data: { contribution_mode: 'BUILD' } }),
-        outcome({ event: 'pr_opened', target: { repo: 'o/r', issue_number: 2 }, data: { contribution_mode: 'BUILD' } })
+        outcome({ event: 'selected', contribution_mode: 'BUILD' }),
+        outcome({ event: 'pr_opened', target: { repo: 'o/r', issue_number: 2 }, contribution_mode: 'BUILD' })
       ]
     });
     expect(result.items[0]?.primary_mode).toBe('BUILD');
diff --git a/test/routing-eval.test.ts b/test/routing-eval.test.ts
new file mode 100644
index 0000000..328dbc8
--- /dev/null
+++ b/test/routing-eval.test.ts
@@ -0,0 +1,71 @@
+import { describe, expect, it } from 'vitest';
+import { OutcomeEventSchema } from '../src/contracts/outcomes.js';
+import { EvalGroundTruthSchema } from '../src/contracts/eval.js';
+import { runReconstructedRoutingEval } from '../src/core/routing-eval.js';
+import { reconstructedRoutingCases } from '../src/core/routing-eval-cases.js';
+import { routeContribution } from '../src/decision/contribution-route.js';
+import type { RouteFacts } from '../src/contracts/routing.js';
+
+describe('routing eval reconstructed partition', () => {
+  it('keeps reconstructed cases out of headline accuracy and forbids occupied BUILD', () => {
+    const metrics = runReconstructedRoutingEval();
+    expect(metrics.reconstructed_cases).toBe(reconstructedRoutingCases.length);
+    expect(metrics.snapshot_cases).toBe(0);
+    expect(metrics.mode_top1_accuracy).toBeNull();
+    expect(metrics.headline_excludes_reconstructed).toBe(true);
+    expect(metrics.false_build_occupied).toBe(0);
+    for (const item of reconstructedRoutingCases) {
+      const decision = routeContribution(item.facts as unknown as RouteFacts);
+      expect(
+        [item.expected.primary_mode, ...item.expected.acceptable_modes],
+        item.id
+      ).toContain(decision.primary_mode);
+      expect(item.expected.forbidden_modes, item.id).not.toContain(decision.primary_mode);
+    }
+  });
+
+  it('covers seed modes including adversarial ownership cases', () => {
+    const ids = reconstructedRoutingCases.map((item) => item.id);
+    expect(ids).toEqual(expect.arrayContaining([
+      'recon-unoccupied-bug-build',
+      'recon-missing-repro',
+      'recon-explicit-closer',
+      'recon-released-fix',
+      'adv-closer-provider-error',
+      'adv-title-overlap-only'
+    ]));
+  });
+
+  it('still parses legacy outcomes without contribution_mode', () => {
+    const parsed = OutcomeEventSchema.parse({
+      event_version: 1,
+      event_id: 'e1',
+      decision_id: 'd1',
+      run_id: 'r1',
+      target: { repo: 'o/r', issue_number: 1 },
+      event: 'selected',
+      occurred_at: '2026-08-01T00:00:00.000Z',
+      source: 'test',
+      data: {},
+      notes: ''
+    });
+    expect(parsed.contribution_mode).toBeUndefined();
+  });
+
+  it('accepts additive routing ground truth', () => {
+    const parsed = EvalGroundTruthSchema.parse({
+      verdict: 'SKIP',
+      disposition: 'land_only',
+      failure_mode: 'occupied_closer',
+      adjudicator_rationale: 'explicit closer owns the issue',
+      evidence_urls: ['https://example.com/issue'],
+      routing: {
+        primary_mode: 'REVIEW',
+        acceptable_modes: ['WATCH'],
+        forbidden_modes: ['BUILD'],
+        build_contention: 'RED'
+      }
+    });
+    expect(parsed.routing?.forbidden_modes).toContain('BUILD');
+  });
+});