diff --git a/src/services/decision-pack.ts b/src/services/decision-pack.ts
index 0001ae19a4..3166293c71 100644
--- a/src/services/decision-pack.ts
+++ b/src/services/decision-pack.ts
@@ -23,7 +23,7 @@ import {
 } from "../db/repositories";
 import { contributorRepoStatsFromGittensor, fetchGittensorContributorSnapshot } from "../gittensor/api";
 import { fetchPublicContributorProfile } from "../github/public";
-import { getOrCreateScoringModelSnapshot } from "../scoring/model";
+import { DEFAULT_SCORING_CONSTANTS, getOrCreateScoringModelSnapshot } from "../scoring/model";
 import {
   buildContributorFit,
   buildContributorOutcomeHistory,
@@ -70,6 +70,12 @@ import { nowIso } from "../utils/json";
 
 export const CONTRIBUTOR_DECISION_PACK_SIGNAL = "contributor-decision-pack";
 export const DECISION_PACK_MAX_AGE_MS = 6 * 60 * 60 * 1000;
+const DEFAULT_OSS_EMISSION_SHARE = DEFAULT_SCORING_CONSTANTS.OSS_EMISSION_SHARE ?? 0.9;
+
+function resolveOssEmissionShare(constants: Record<string, number> | undefined): number {
+  const value = constants?.OSS_EMISSION_SHARE;
+  return typeof value === "number" && Number.isFinite(value) ? value : DEFAULT_OSS_EMISSION_SHARE;
+}
 export const DECISION_PACK_REBUILD_DEBOUNCE_MS = 15 * 1000;
 const pendingDecisionPackRebuilds = new Map<string, Promise<boolean>>();
 
@@ -469,6 +475,7 @@ export async function buildAndPersistContributorDecisionPack(env: Env, login: st
     totals,
     opportunities: fit.opportunities,
     scoringModelSnapshotId: scoringSnapshot.id,
+    ossEmissionShare: resolveOssEmissionShare(scoringSnapshot.constants),
     contributorPullRequests,
     contributorIssues,
     repoStats,
@@ -546,6 +553,7 @@ function buildContributorDecisionPack(args: {
   focusManifests?: Map<string, FocusManifest> | undefined;
   repoOutcomePatternsByRepo?: Map<string, RepoOutcomePatterns> | undefined;
   recommendationOutcomeFeedback?: AgentRecommendationOutcomeSummary | undefined;
+  ossEmissionShare?: number | undefined;
 }): ContributorDecisionPack {
   const recommendationOutcomeFeedback = args.recommendationOutcomeFeedback ?? emptyRecommendationOutcomeFeedback(args.login);
   const registeredRepositories = args.repositories.filter((repo) => repo.isRegistered);
@@ -584,6 +592,7 @@ function buildContributorDecisionPack(args: {
         focusManifest: args.focusManifests?.get(key),
         repoOutcomePatterns: args.repoOutcomePatternsByRepo?.get(key),
         recommendationOutcomeFeedback: recommendationFeedbackByRepo.get(key),
+        ossEmissionShare: args.ossEmissionShare,
       });
     })
     .sort((left, right) => right.priorityScore - left.priorityScore || left.repoFullName.localeCompare(right.repoFullName));
@@ -665,9 +674,12 @@ function buildRepoDecision(args: {
   focusManifest?: FocusManifest | undefined;
   repoOutcomePatterns?: RepoOutcomePatterns | undefined;
   recommendationOutcomeFeedback?: AgentRecommendationOutcomeRepoSummary | undefined;
+  ossEmissionShare?: number | undefined;
 }): RepoDecision {
   const lane = buildLaneAdvice(args.repo, args.repo.fullName);
   const config = args.repo.registryConfig;
+  const ossEmissionShare =
+    typeof args.ossEmissionShare === "number" && Number.isFinite(args.ossEmissionShare) ? args.ossEmissionShare : DEFAULT_OSS_EMISSION_SHARE;
   const openPullRequests = args.totals?.openPullRequestsTotal ?? args.syncState?.openPullRequestsCount ?? 0;
   const openIssues = args.totals?.openIssuesTotal ?? args.syncState?.openIssuesCount ?? 0;
   const queue = {
@@ -676,10 +688,14 @@ function buildRepoDecision(args: {
     mergedPullRequests: args.totals?.mergedPullRequestsTotal ?? args.syncState?.recentMergedPullRequestsCount ?? 0,
     closedUnmergedPullRequests: args.totals?.closedUnmergedPullRequestsTotal ?? 0,
   };
+  const baseEmissionShare = config?.emissionShare ?? 0;
+  // Lane shares are a split of the OSS *mining* pool (emissionShare * OSS_EMISSION_SHARE), matching
+  // preview.ts laneMath (directPrSlice/issueDiscoverySlice) and reward-risk.ts. The raw emissionShare
+  // field stays raw (it mirrors laneMath.repoEmissionShare).
   const rewardUpside = {
-    emissionShare: round(config?.emissionShare ?? 0),
-    directPrShare: round((config?.emissionShare ?? 0) * (1 - (config?.issueDiscoveryShare ?? 0))),
-    issueDiscoveryShare: round((config?.emissionShare ?? 0) * (config?.issueDiscoveryShare ?? 0)),
+    emissionShare: round(baseEmissionShare),
+    directPrShare: round(baseEmissionShare * ossEmissionShare * (1 - (config?.issueDiscoveryShare ?? 0))),
+    issueDiscoveryShare: round(baseEmissionShare * ossEmissionShare * (config?.issueDiscoveryShare ?? 0)),
     maintainerCut: round(config?.maintainerCut ?? 0),
   };
   const blockers = scoreBlockersFor(args.repo.fullName, lane.lane, args.roleContext, args.outcome);
diff --git a/test/unit/decision-pack.test.ts b/test/unit/decision-pack.test.ts
index 9ac4e5d07e..7e5f01cd7e 100644
--- a/test/unit/decision-pack.test.ts
+++ b/test/unit/decision-pack.test.ts
@@ -96,7 +96,7 @@ describe("decision-pack service", () => {
         outcome: undefined,
         syncState: { openPullRequestsCount: 1, openIssuesCount: 2, recentMergedPullRequestsCount: 3 } as any,
       }),
-    ).toMatchObject({ recommendation: "watch", queue: { openPullRequests: 1, openIssues: 2, mergedPullRequests: 3 }, rewardUpside: { issueDiscoveryShare: 0.02 } });
+    ).toMatchObject({ recommendation: "watch", queue: { openPullRequests: 1, openIssues: 2, mergedPullRequests: 3 }, rewardUpside: { issueDiscoveryShare: 0.018 } });
     expect(
       __decisionPackInternals.buildRepoDecision({
         repo: repo("owner/inactive", 0, 0),
@@ -111,6 +111,31 @@ describe("decision-pack service", () => {
     expect(__decisionPackInternals.round(1.23456)).toBe(1.2346);
   });
 
+  it("applies OSS_EMISSION_SHARE to rewardUpside lane shares (not the raw emission share)", () => {
+    const outsideRole = { maintainerLane: false } as any;
+    // Split repo: emissionShare 0.04, issueDiscoveryShare 0.25. Lane shares are a split of the OSS
+    // mining pool (emissionShare * 0.9), matching preview.ts laneMath / reward-risk.ts -- NOT the raw split.
+    const split = __decisionPackInternals.buildRepoDecision({
+      repo: repo("owner/split", 0.04, 0.25),
+      roleContext: outsideRole,
+      outcome: undefined,
+    }).rewardUpside;
+    expect(split.emissionShare).toBe(0.04); // raw value preserved (mirrors laneMath.repoEmissionShare)
+    expect(split.directPrShare).toBeCloseTo(0.04 * 0.9 * 0.75, 10); // 0.027
+    expect(split.issueDiscoveryShare).toBeCloseTo(0.04 * 0.9 * 0.25, 10); // 0.009
+    // A single lane share can never exceed the repo's whole OSS mining pool (emissionShare * 0.9).
+    expect(split.directPrShare).toBeLessThanOrEqual(0.04 * 0.9 + 1e-9);
+
+    // An explicit snapshot-provided OSS_EMISSION_SHARE override is honored.
+    const overridden = __decisionPackInternals.buildRepoDecision({
+      repo: repo("owner/override", 0.04, 0),
+      roleContext: outsideRole,
+      outcome: undefined,
+      ossEmissionShare: 0.8,
+    }).rewardUpside;
+    expect(overridden.directPrShare).toBeCloseTo(0.04 * 0.8, 10); // 0.032
+  });
+
   it("feeds repo outcome patterns into repo decisions without inflating maintainer-lane evidence", () => {
     const outsideRole = { maintainerLane: false } as any;
     const maintainerRole = { maintainerLane: true } as any;
@@ -1048,7 +1073,8 @@ describe("decision-pack service", () => {
         summary: "0 open issues evaluated.",
       },
     });
-    expect(emptyQualityDecision.priorityScore).toBe(40);
+    // 38, not 40: upside = issueDiscoveryShare (0.02 * OSS_EMISSION_SHARE 0.9 = 0.018) * 1000 = 18.
+    expect(emptyQualityDecision.priorityScore).toBe(38);
   });
 
   it("issues avoid_for_now reasoning with sanitized public copy", () => {