diff --git a/app/api/credits/sessions/__tests__/route.post.outcomes.test.ts b/app/api/credits/sessions/__tests__/route.post.outcomes.test.ts
index 279f0662f..646b043bc 100644
--- a/app/api/credits/sessions/__tests__/route.post.outcomes.test.ts
+++ b/app/api/credits/sessions/__tests__/route.post.outcomes.test.ts
@@ -14,7 +14,7 @@ const makeReq = () => new NextRequest(URL, { method: "POST", body: "{}" });
 const validated = {
   accountId: ACCOUNT,
   successUrl: "https://chat.recoupable.com/ok",
-  credits: 250,
+  credits: 2_500_000,
 };
 
 describe("POST /api/credits/sessions (handler outcomes)", () => {
@@ -43,7 +43,7 @@ describe("POST /api/credits/sessions (handler outcomes)", () => {
     expect(res.status).toBe(200);
     await expect(res.json()).resolves.toEqual({
       paymentIntentId: "pi_ok",
-      creditsPurchased: 250,
+      creditsPurchased: 2_500_000,
       totalCents: 289,
     });
   });
diff --git a/lib/artist/__tests__/postArtistSocialsScrapeHandler.test.ts b/lib/artist/__tests__/postArtistSocialsScrapeHandler.test.ts
index 7e64203e3..dad1c1fac 100644
--- a/lib/artist/__tests__/postArtistSocialsScrapeHandler.test.ts
+++ b/lib/artist/__tests__/postArtistSocialsScrapeHandler.test.ts
@@ -74,7 +74,7 @@ describe("postArtistSocialsScrapeHandler", () => {
     expect(scrapeProfileUrlBatch).not.toHaveBeenCalled();
   });
 
-  it("gates on (5 + posts) × profiles credits and short-circuits with the 402", async () => {
+  it("gates on ($0.05 + $0.01 × posts) × profiles and short-circuits with the 402", async () => {
     const short = NextResponse.json({}, { status: 402 });
     vi.mocked(ensureSocialScrapeCredits).mockResolvedValue(short);
     expect(
@@ -82,14 +82,14 @@ describe("postArtistSocialsScrapeHandler", () => {
         makeRequest({ artist_account_id: ARTIST_ID, posts: 20 }),
       ),
     ).toBe(short);
-    expect(ensureSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 50);
+    expect(ensureSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 500_000);
     expect(scrapeProfileUrlBatch).not.toHaveBeenCalled();
   });
 
-  it("scrapes without a posts depth by default and deducts 5 credits per scraped profile", async () => {
+  it("scrapes without a posts depth by default and deducts $0.05 per scraped profile", async () => {
     const res = await postArtistSocialsScrapeHandler(makeRequest({ artist_account_id: ARTIST_ID }));
     expect(res.status).toBe(200);
-    expect(ensureSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 10);
+    expect(ensureSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 100_000);
     expect(scrapeProfileUrlBatch).toHaveBeenCalledWith(
       [
         { profileUrl: "https://x.com/a", username: "a" },
@@ -97,17 +97,17 @@ describe("postArtistSocialsScrapeHandler", () => {
       ],
       undefined,
     );
-    expect(deductSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 10);
+    expect(deductSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 100_000);
   });
 
-  it("forwards posts and deducts (5 + posts) per profile actually scraped", async () => {
+  it("forwards posts and deducts ($0.05 + $0.01 × posts) per profile actually scraped", async () => {
     vi.mocked(scrapeProfileUrlBatch).mockResolvedValue([
       { runId: "r1", datasetId: "d1", error: null, profileUrl: null },
     ]);
     await postArtistSocialsScrapeHandler(makeRequest({ artist_account_id: ARTIST_ID, posts: 20 }));
-    expect(ensureSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 50);
+    expect(ensureSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 500_000);
     expect(scrapeProfileUrlBatch).toHaveBeenCalledWith(expect.any(Array), 20);
-    expect(deductSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 25);
+    expect(deductSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 250_000);
   });
 
   it("returns [] and charges nothing when the artist has no socials", async () => {
diff --git a/lib/chat/__tests__/integration/chatEndToEnd.test.ts b/lib/chat/__tests__/integration/chatEndToEnd.test.ts
index 507eece0a..c1cfb41c9 100644
--- a/lib/chat/__tests__/integration/chatEndToEnd.test.ts
+++ b/lib/chat/__tests__/integration/chatEndToEnd.test.ts
@@ -373,7 +373,7 @@ describe("Chat Integration Tests", () => {
       expect(mockRecordCreditDeduction).toHaveBeenCalledWith(
         expect.objectContaining({
           accountId: "account-123",
-          creditsToDeduct: 50, // 0.5 * 100
+          creditsToDeduct: 500_000, // $0.50 in micro-dollars
           source: "web",
         }),
       );
@@ -431,7 +431,7 @@ describe("Chat Integration Tests", () => {
       expect(mockRecordCreditDeduction).toHaveBeenCalledWith(
         expect.objectContaining({
           accountId: "account-123",
-          creditsToDeduct: 1, // Math.max(1, Math.round(0.001 * 100))
+          creditsToDeduct: 1_000, // $0.001 in micro-dollars
           source: "web",
         }),
       );
diff --git a/lib/chat/validateChatRequest.ts b/lib/chat/validateChatRequest.ts
index 12ad41ccf..195be434f 100644
--- a/lib/chat/validateChatRequest.ts
+++ b/lib/chat/validateChatRequest.ts
@@ -8,6 +8,8 @@ import { getMessages } from "@/lib/messages/getMessages";
 import convertToUiMessages from "@/lib/messages/convertToUiMessages";
 import { setupConversation } from "@/lib/chat/setupConversation";
 import { validateMessages } from "@/lib/chat/validateMessages";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 export const chatRequestSchema = z
   .object({
@@ -99,7 +101,7 @@ export async function validateChatRequest(
   // billing; nothing is charged and no Stripe object is created.
   const short = await ensureCreditsOrShortCircuit({
     accountId,
-    creditsToDeduct: 1,
+    creditsToDeduct: usdToCredits(PRICES_USD.chatMinimum),
   });
   if (short) return short;
 
diff --git a/lib/credits/__tests__/checkAndResetCredits.test.ts b/lib/credits/__tests__/checkAndResetCredits.test.ts
index 3cb7843d0..105afa6da 100644
--- a/lib/credits/__tests__/checkAndResetCredits.test.ts
+++ b/lib/credits/__tests__/checkAndResetCredits.test.ts
@@ -154,7 +154,7 @@ describe("checkAndResetCredits", () => {
   });
 
   it("reports isPro=true without refilling when sub is active but neither refill trigger fires", async () => {
-    const row = baseRow({ timestamp: "2026-05-01T00:00:00.000Z", remaining_credits: 800 });
+    const row = baseRow({ timestamp: "2026-05-01T00:00:00.000Z", remaining_credits: 8_000_000 });
     vi.mocked(selectCreditsUsage).mockResolvedValue([row]);
     vi.mocked(getAccountSubscriptionState).mockResolvedValue(proStateFromAccount);
 
@@ -186,7 +186,10 @@ describe("checkAndResetCredits", () => {
     });
 
     it("leaves a balance ABOVE the plan total untouched, and still advances the timestamp", async () => {
-      const row = baseRow({ timestamp: "2026-03-01T00:00:00.000Z", remaining_credits: 9999 });
+      const row = baseRow({
+        timestamp: "2026-03-01T00:00:00.000Z",
+        remaining_credits: PRO_CREDITS,
+      });
       vi.mocked(selectCreditsUsage).mockResolvedValue([row]);
       vi.mocked(updateCreditsUsage).mockResolvedValue({
         ...row,
@@ -196,13 +199,13 @@ describe("checkAndResetCredits", () => {
 
       const result = await checkAndResetCredits(ACCOUNT);
 
-      // remaining_credits is absent from the update, not set to 9999: a stale
+      // remaining_credits is absent from the update, not set to PRO_CREDITS: a stale
       // read must not resurrect credits a concurrent deduction just spent.
       expect(updateCreditsUsage).toHaveBeenCalledWith({
         account_id: ACCOUNT,
         updates: { timestamp: "2026-05-11T12:00:00.000Z" },
       });
-      expect(result.creditsUsage?.remaining_credits).toBe(9999);
+      expect(result.creditsUsage?.remaining_credits).toBe(PRO_CREDITS);
     });
 
     it("writes only the timestamp when the balance is exactly the plan total", async () => {
@@ -226,7 +229,10 @@ describe("checkAndResetCredits", () => {
     });
 
     it("does not cut a pro account holding more than PRO_CREDITS", async () => {
-      const row = baseRow({ timestamp: "2026-03-01T00:00:00.000Z", remaining_credits: 25000 });
+      const row = baseRow({
+        timestamp: "2026-03-01T00:00:00.000Z",
+        remaining_credits: PRO_CREDITS + 1,
+      });
       vi.mocked(selectCreditsUsage).mockResolvedValue([row]);
       vi.mocked(updateCreditsUsage).mockResolvedValue({
         ...row,
@@ -240,13 +246,16 @@ describe("checkAndResetCredits", () => {
         account_id: ACCOUNT,
         updates: { timestamp: "2026-05-11T12:00:00.000Z" },
       });
-      expect(result.creditsUsage?.remaining_credits).toBe(25000);
+      expect(result.creditsUsage?.remaining_credits).toBe(PRO_CREDITS + 1);
     });
 
     it("protects an admin grant on a free account without knowing it is a grant", async () => {
       // 9,999 granted to a free-tier account: no provenance is consulted, the
       // floor rule alone keeps it.
-      const row = baseRow({ timestamp: "2026-03-01T00:00:00.000Z", remaining_credits: 9999 });
+      const row = baseRow({
+        timestamp: "2026-03-01T00:00:00.000Z",
+        remaining_credits: PRO_CREDITS,
+      });
       vi.mocked(selectCreditsUsage).mockResolvedValue([row]);
       vi.mocked(updateCreditsUsage).mockResolvedValue({
         ...row,
@@ -258,12 +267,15 @@ describe("checkAndResetCredits", () => {
 
       const [{ updates }] = vi.mocked(updateCreditsUsage).mock.calls[0];
       expect(updates).not.toHaveProperty("remaining_credits");
-      expect(result.creditsUsage?.remaining_credits).toBe(9999);
+      expect(result.creditsUsage?.remaining_credits).toBe(PRO_CREDITS);
       expect(result.creditsUsage?.remaining_credits).not.toBe(DEFAULT_CREDITS);
     });
 
     it("treats a newly-subscribed refill as a floor too (does not cut a topped-up balance)", async () => {
-      const row = baseRow({ timestamp: "2026-05-05T00:00:00.000Z", remaining_credits: 12000 });
+      const row = baseRow({
+        timestamp: "2026-05-05T00:00:00.000Z",
+        remaining_credits: PRO_CREDITS + 2_001_000,
+      });
       vi.mocked(selectCreditsUsage).mockResolvedValue([row]);
       vi.mocked(updateCreditsUsage).mockResolvedValue({
         ...row,
@@ -277,7 +289,7 @@ describe("checkAndResetCredits", () => {
         account_id: ACCOUNT,
         updates: { timestamp: "2026-05-11T12:00:00.000Z" },
       });
-      expect(result.creditsUsage?.remaining_credits).toBe(12000);
+      expect(result.creditsUsage?.remaining_credits).toBe(PRO_CREDITS + 2_001_000);
     });
   });
 });
diff --git a/lib/credits/__tests__/const.test.ts b/lib/credits/__tests__/const.test.ts
index 10438429d..5dc29d6ab 100644
--- a/lib/credits/__tests__/const.test.ts
+++ b/lib/credits/__tests__/const.test.ts
@@ -1,13 +1,15 @@
-import { describe, expect, it } from "vitest";
+import { describe, it, expect } from "vitest";
+import { DEFAULT_CREDITS, DEFAULT_CREDITS_USD, PRO_CREDITS, PRO_CREDITS_USD } from "../const";
+import { usdToCredits } from "../usdToCredits";
 
-import { DEFAULT_CREDITS, PRO_CREDITS } from "@/lib/credits/const";
-
-describe("credit plan constants", () => {
-  it("keeps the free-tier allotment at 333 (matches chat/lib/consts.ts)", () => {
-    expect(DEFAULT_CREDITS).toBe(333);
+describe("credit grant totals", () => {
+  it("derive from their dollar values through the shared conversion", () => {
+    expect(DEFAULT_CREDITS).toBe(usdToCredits(DEFAULT_CREDITS_USD));
+    expect(PRO_CREDITS).toBe(usdToCredits(PRO_CREDITS_USD));
   });
 
-  it("gives pro accounts 9999 credits per month (matches chat/lib/consts.ts)", () => {
-    expect(PRO_CREDITS).toBe(9999);
+  it("are $3.33 and $99.99 in micro-dollars", () => {
+    expect(DEFAULT_CREDITS).toBe(3_330_000);
+    expect(PRO_CREDITS).toBe(99_990_000);
   });
 });
diff --git a/lib/credits/__tests__/creditsToUsd.test.ts b/lib/credits/__tests__/creditsToUsd.test.ts
new file mode 100644
index 000000000..16d996530
--- /dev/null
+++ b/lib/credits/__tests__/creditsToUsd.test.ts
@@ -0,0 +1,15 @@
+import { describe, it, expect } from "vitest";
+import { creditsToUsd } from "../creditsToUsd";
+import { usdToCredits } from "../usdToCredits";
+
+describe("creditsToUsd", () => {
+  it("keeps the two directions consistent at the unit boundary", () => {
+    expect(creditsToUsd(1_000_000)).toBe(1);
+    expect(creditsToUsd(92_440_000)).toBe(92.44);
+    expect(creditsToUsd(usdToCredits(4.12))).toBe(4.12);
+  });
+
+  it("carries sub-cent amounts", () => {
+    expect(creditsToUsd(51_740)).toBe(0.05174);
+  });
+});
diff --git a/lib/credits/__tests__/formatCreditSpendDigest.test.ts b/lib/credits/__tests__/formatCreditSpendDigest.test.ts
index 440dc9a8e..0bc05ae09 100644
--- a/lib/credits/__tests__/formatCreditSpendDigest.test.ts
+++ b/lib/credits/__tests__/formatCreditSpendDigest.test.ts
@@ -7,15 +7,15 @@ function row(overrides: Partial<CreditSpendDigestRow> = {}): CreditSpendDigestRo
     account_id: "acc-1",
     account_name: "Jane",
     account_email: "jane@example.com",
-    total_cents: 412,
+    total_cents: 4_120_000,
     turn_count: 7,
     input_tokens: 1_200_000,
     output_tokens: 40_000,
     cached_input_tokens: 0,
     tool_calls: 3,
-    main_cents: 412,
+    main_cents: 4_120_000,
     subagent_cents: 0,
-    by_model: { "claude-opus": 300, "claude-haiku": 112 },
+    by_model: { "claude-opus": 3_000_000, "claude-haiku": 1_120_000 },
     ...overrides,
   };
 }
@@ -56,7 +56,10 @@ describe("formatCreditSpendDigest", () => {
   });
 
   it("shows the main/subagent split when subagent spend exists", () => {
-    const out = formatCreditSpendDigest([row({ main_cents: 300, subagent_cents: 112 })], 10);
+    const out = formatCreditSpendDigest(
+      [row({ main_cents: 3_000_000, subagent_cents: 1_120_000 })],
+      10,
+    );
     expect(out).toContain("main $3.00 · subagent $1.12");
   });
 
diff --git a/lib/credits/__tests__/getCreditSpendDigestHandler.test.ts b/lib/credits/__tests__/getCreditSpendDigestHandler.test.ts
index fa021ca62..0f55be56c 100644
--- a/lib/credits/__tests__/getCreditSpendDigestHandler.test.ts
+++ b/lib/credits/__tests__/getCreditSpendDigestHandler.test.ts
@@ -27,15 +27,15 @@ const sampleRow: CreditSpendDigestRow = {
   account_id: "acc-1",
   account_name: "Jane",
   account_email: "jane@example.com",
-  total_cents: 412,
+  total_cents: 4_120_000,
   turn_count: 7,
   input_tokens: 1000,
   output_tokens: 200,
   cached_input_tokens: 0,
   tool_calls: 3,
-  main_cents: 412,
+  main_cents: 4_120_000,
   subagent_cents: 0,
-  by_model: { "claude-opus": 412 },
+  by_model: { "claude-opus": 4_120_000 },
 };
 
 beforeEach(() => {
diff --git a/lib/credits/__tests__/handleChatCredits.test.ts b/lib/credits/__tests__/handleChatCredits.test.ts
index c1786fc8f..45ac17004 100644
--- a/lib/credits/__tests__/handleChatCredits.test.ts
+++ b/lib/credits/__tests__/handleChatCredits.test.ts
@@ -33,7 +33,7 @@ describe("handleChatCredits", () => {
 
   describe("credit deduction", () => {
     it("deducts credits and forwards token detail to the usage_events row", async () => {
-      mockGetCreditUsage.mockResolvedValue(0.05); // $0.05 = 5 credits
+      mockGetCreditUsage.mockResolvedValue(0.05); // $0.05 = 50,000 micro-dollars
       mockRecordCreditDeduction.mockResolvedValue({ success: true, newBalance: 95 });
 
       await handleChatCredits({
@@ -45,7 +45,7 @@ describe("handleChatCredits", () => {
       expect(mockGetCreditUsage).toHaveBeenCalledWith(USAGE, "gpt-4", undefined);
       expect(mockRecordCreditDeduction).toHaveBeenCalledWith({
         accountId: "account-123",
-        creditsToDeduct: 5,
+        creditsToDeduct: 50_000,
         source: "web",
         modelId: "gpt-4",
         inputTokens: 1000,
@@ -55,7 +55,7 @@ describe("handleChatCredits", () => {
     });
 
     it("rounds credits to at least 1 when cost is very small", async () => {
-      mockGetCreditUsage.mockResolvedValue(0.001);
+      mockGetCreditUsage.mockResolvedValue(0.0000001);
       mockRecordCreditDeduction.mockResolvedValue({ success: true, newBalance: 99 });
 
       await handleChatCredits({
@@ -80,7 +80,7 @@ describe("handleChatCredits", () => {
       });
 
       expect(mockRecordCreditDeduction).toHaveBeenCalledWith(
-        expect.objectContaining({ accountId: "account-123", creditsToDeduct: 123 }),
+        expect.objectContaining({ accountId: "account-123", creditsToDeduct: 1_234_000 }),
       );
     });
   });
diff --git a/lib/credits/__tests__/usdToCredits.test.ts b/lib/credits/__tests__/usdToCredits.test.ts
new file mode 100644
index 000000000..c01818ac9
--- /dev/null
+++ b/lib/credits/__tests__/usdToCredits.test.ts
@@ -0,0 +1,31 @@
+import { describe, it, expect } from "vitest";
+import { usdToCredits } from "../usdToCredits";
+import { CREDIT_DECIMALS } from "../creditDecimals";
+
+describe("usdToCredits", () => {
+  it("is the USDC unit: six decimals, a million per dollar", () => {
+    expect(CREDIT_DECIMALS).toBe(6);
+    expect(usdToCredits(1)).toBe(1_000_000);
+    expect(usdToCredits(92.44)).toBe(92_440_000);
+  });
+
+  it("converts fractional dollars exactly, without floating-point drift", () => {
+    // 0.12 * 1e6 is 119999.99999999999 in IEEE-754; the ledger must see 120000.
+    expect(usdToCredits(0.12)).toBe(120_000);
+    expect(usdToCredits(0.002 * 25.87)).toBe(51_740);
+  });
+
+  it("never rounds up: a fraction of the ledger unit is absorbed, not charged", () => {
+    // recoupable/app#2000, owner decision 2026-08-27: pass provider prices
+    // through; the unit is the precision and any residue below it is ours.
+    expect(usdToCredits(0.0000019)).toBe(1);
+    expect(usdToCredits(0.1234567)).toBe(123_456);
+  });
+
+  it("charges at least one ledger unit, even for a zero or sub-unit cost", () => {
+    // A request that reached a model is never free: the minimum is one
+    // micro-dollar.
+    expect(usdToCredits(0)).toBe(1);
+    expect(usdToCredits(0.0000001)).toBe(1);
+  });
+});
diff --git a/lib/credits/const.ts b/lib/credits/const.ts
index 4cb6405ad..0a2e704bf 100644
--- a/lib/credits/const.ts
+++ b/lib/credits/const.ts
@@ -1,15 +1,23 @@
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+
 /**
- * Monthly credit allotment for free-tier accounts.
+ * Monthly credit allotment for free-tier accounts, as dollars.
  * Matches `chat/lib/consts.ts` so the chat sidebar and the public API agree.
  */
-export const DEFAULT_CREDITS = 333;
+export const DEFAULT_CREDITS_USD = 3.33;
+
+/** Free-tier allotment in credits. Derived, so it survives a unit change. */
+export const DEFAULT_CREDITS = usdToCredits(DEFAULT_CREDITS_USD);
 
 /**
  * Monthly credit allotment for accounts on a pro plan (directly, via an
  * organization, or via an enterprise email domain). Effectively "don't think
  * about credits" for paying customers.
  */
-export const PRO_CREDITS = 9999;
+export const PRO_CREDITS_USD = 99.99;
+
+/** Pro allotment in credits. Derived, so it survives a unit change. */
+export const PRO_CREDITS = usdToCredits(PRO_CREDITS_USD);
 
 /**
  * Where a caller that ran out of credits is pointed. A constant, so a 402
diff --git a/lib/credits/creditDecimals.ts b/lib/credits/creditDecimals.ts
new file mode 100644
index 000000000..99a35c244
--- /dev/null
+++ b/lib/credits/creditDecimals.ts
@@ -0,0 +1,14 @@
+/**
+ * Decimal places in a credit: the single definition of what a credit is worth.
+ *
+ * Six, the same unit as USDC: 1,000,000 credits = $1.00, so a credit is a
+ * micro-dollar and provider prices pass through exactly. Every conversion
+ * between credits and dollars goes through `usdToCredits` or `creditsToUsd`,
+ * which are viem's `parseUnits` / `formatUnits` at this precision.
+ *
+ * Must match `chat/lib/credits/creditDecimals.ts` and the values stored in
+ * `credits_usage.remaining_credits`; the database rescale
+ * (recoupable/app#2000, database#62) and the deploy of this constant have to
+ * land in the same window or every charge is off by the ratio between them.
+ */
+export const CREDIT_DECIMALS = 6;
diff --git a/lib/credits/creditsToStripeCents.ts b/lib/credits/creditsToStripeCents.ts
new file mode 100644
index 000000000..963824b4a
--- /dev/null
+++ b/lib/credits/creditsToStripeCents.ts
@@ -0,0 +1,15 @@
+import { creditsToUsd } from "@/lib/credits/creditsToUsd";
+
+/**
+ * Whole Stripe cents for a credit amount.
+ *
+ * Stripe bills in cents whatever the ledger unit is. Top-up requests are
+ * validated to whole cents (`credits` a multiple of 10^(CREDIT_DECIMALS - 2)),
+ * so this is exact; the rounding only guards floating point.
+ *
+ * @param credits - Credits, whole ledger units.
+ * @returns Cents, integer.
+ */
+export function creditsToStripeCents(credits: number): number {
+  return Math.round(creditsToUsd(credits) * 100);
+}
diff --git a/lib/credits/creditsToUsd.ts b/lib/credits/creditsToUsd.ts
new file mode 100644
index 000000000..f629b531c
--- /dev/null
+++ b/lib/credits/creditsToUsd.ts
@@ -0,0 +1,13 @@
+import { formatUnits } from "viem";
+import { CREDIT_DECIMALS } from "@/lib/credits/creditDecimals";
+
+/**
+ * Dollar value of a credit amount (viem's `formatUnits` at the credit
+ * precision, so 92,440,000 → 92.44 exactly).
+ *
+ * @param credits - Credit amount, whole ledger units.
+ * @returns Dollars, unformatted.
+ */
+export function creditsToUsd(credits: number): number {
+  return Number(formatUnits(BigInt(Math.trunc(credits)), CREDIT_DECIMALS));
+}
diff --git a/lib/credits/formatCentsAsUsd.ts b/lib/credits/formatCentsAsUsd.ts
index 9b229312b..6eb3b21cd 100644
--- a/lib/credits/formatCentsAsUsd.ts
+++ b/lib/credits/formatCentsAsUsd.ts
@@ -1,9 +1,15 @@
+import { creditsToUsd } from "@/lib/credits/creditsToUsd";
+
 /**
- * Formats an integer cent amount as a USD string.
+ * Formats a credit amount as a USD string.
  *
- * @param cents - Amount in cents (e.g. 412).
+ * Named for cents because that is what a credit is worth today; the
+ * conversion goes through `creditsToUsd` so the name is the only thing that
+ * has to change when the unit does (recoupable/chat#2000).
+ *
+ * @param cents - Credit amount (e.g. 412).
  * @returns USD string (e.g. "$4.12").
  */
 export function formatCentsAsUsd(cents: number): string {
-  return `$${(cents / 100).toFixed(2)}`;
+  return `$${creditsToUsd(cents).toFixed(2)}`;
 }
diff --git a/lib/credits/getCreditUsage.ts b/lib/credits/getCreditUsage.ts
index 26eb9180b..e9bd865bc 100644
--- a/lib/credits/getCreditUsage.ts
+++ b/lib/credits/getCreditUsage.ts
@@ -12,7 +12,7 @@ import { LanguageModelUsage } from "ai";
  *   2. Token-based estimate using `model.pricing.input/output` from
  *      the gateway catalog (`getModel`). Authoritative for token cost.
  *   3. `0` when nothing prices the turn (caller floors to the 1c
- *      minimum via `Math.max(1, Math.round(usd * 100))`).
+ *      minimum via `usdToCredits`, which floors at one credit).
  *
  * @param usage - The language model usage data
  * @param modelId - The ID of the model used
diff --git a/lib/credits/handleChatCredits.ts b/lib/credits/handleChatCredits.ts
index 98c8ecdbc..68f2b8c8c 100644
--- a/lib/credits/handleChatCredits.ts
+++ b/lib/credits/handleChatCredits.ts
@@ -1,4 +1,5 @@
 import { getCreditUsage } from "./getCreditUsage";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
 import { recordCreditDeduction } from "./recordCreditDeduction";
 import { LanguageModelUsage } from "ai";
 
@@ -49,7 +50,7 @@ export const handleChatCredits = async ({
 
   try {
     const usageCost = await getCreditUsage(usage, model, gatewayCostUsd);
-    const creditsToDeduct = Math.max(1, Math.round(usageCost * 100));
+    const creditsToDeduct = usdToCredits(usageCost);
 
     await recordCreditDeduction({
       accountId,
diff --git a/lib/credits/pricesUsd.ts b/lib/credits/pricesUsd.ts
new file mode 100644
index 000000000..b065cc435
--- /dev/null
+++ b/lib/credits/pricesUsd.ts
@@ -0,0 +1,20 @@
+/**
+ * Fixed per-call prices, in US dollars.
+ *
+ * The one place a flat price is written down. Handlers convert at the call
+ * site with `usdToCredits`, so the ledger unit (recoupable/app#2000) never
+ * leaks into a handler as a bare number. Per-use pricing (chat tokens, music
+ * seconds) is computed from the provider's rate instead and is not listed.
+ */
+export const PRICES_USD = {
+  chatMinimum: 0.01,
+  research: 0.05,
+  researchPeople: 0.05,
+  researchWeb: 0.01,
+  researchEvents: 0.01,
+  researchExtractPerUrl: 0.05,
+  researchDeep: 0.25,
+  researchEnrich: { base: 0.05, core: 0.1, ultra: 0.25 },
+  socialScrapeBase: 0.05,
+  socialScrapePerPost: 0.01,
+} as const;
diff --git a/lib/credits/usdToCredits.ts b/lib/credits/usdToCredits.ts
new file mode 100644
index 000000000..e92acb5c7
--- /dev/null
+++ b/lib/credits/usdToCredits.ts
@@ -0,0 +1,24 @@
+import { parseUnits } from "viem";
+import { CREDIT_DECIMALS } from "@/lib/credits/creditDecimals";
+
+/**
+ * Credits for a dollar amount, in whole ledger units.
+ *
+ * Two rules, decided on recoupable/app#2000 (2026-08-27):
+ * - No rounding up. The dollar figure is truncated to `CREDIT_DECIMALS`
+ *   before `parseUnits` (which would otherwise round half up), so a residue
+ *   below one unit is absorbed by Recoup, never charged. Going through a
+ *   decimal string also sidesteps IEEE-754 noise (0.12 * 1e6 = 119999.99…).
+ * - Minimum one unit. A request that reached a model is never free, even
+ *   when the gateway reports no cost. Callers that genuinely want zero for
+ *   zero (music, where a failed generation costs nothing) decide that before
+ *   calling.
+ *
+ * @param usd - Cost in dollars.
+ * @returns Whole credits, minimum 1.
+ */
+export function usdToCredits(usd: number): number {
+  const [whole, fraction = ""] = usd.toFixed(CREDIT_DECIMALS + 2).split(".");
+  const truncated = `${whole}.${fraction.slice(0, CREDIT_DECIMALS)}`;
+  return Math.max(1, Number(parseUnits(truncated, CREDIT_DECIMALS)));
+}
diff --git a/lib/research/__tests__/deductCredits.test.ts b/lib/research/__tests__/deductCredits.test.ts
index ed1eb0fd3..79ad0be92 100644
--- a/lib/research/__tests__/deductCredits.test.ts
+++ b/lib/research/__tests__/deductCredits.test.ts
@@ -12,7 +12,7 @@ describe("deductCredits", () => {
 
     expect(recordCreditDeduction).toHaveBeenCalledWith({
       accountId: "acc_1",
-      creditsToDeduct: 5,
+      creditsToDeduct: 50_000,
       source: "api",
     });
   });
diff --git a/lib/research/__tests__/ensureWebResearchCredits.test.ts b/lib/research/__tests__/ensureWebResearchCredits.test.ts
index 76105e093..d583ac1d9 100644
--- a/lib/research/__tests__/ensureWebResearchCredits.test.ts
+++ b/lib/research/__tests__/ensureWebResearchCredits.test.ts
@@ -21,7 +21,7 @@ describe("ensureWebResearchCredits", () => {
 
     await expect(ensureWebResearchCredits("acct")).resolves.toBeNull();
     expect(ensureCreditsMock).toHaveBeenCalledWith(
-      expect.objectContaining({ accountId: "acct", creditsToDeduct: 1 }),
+      expect.objectContaining({ accountId: "acct", creditsToDeduct: 10_000 }),
     );
   });
 
diff --git a/lib/research/__tests__/getResearchTrackHistoricStats.test.ts b/lib/research/__tests__/getResearchTrackHistoricStats.test.ts
index b1d621733..be7bd4003 100644
--- a/lib/research/__tests__/getResearchTrackHistoricStats.test.ts
+++ b/lib/research/__tests__/getResearchTrackHistoricStats.test.ts
@@ -34,7 +34,7 @@ describe("getResearchTrackHistoricStats", () => {
     expect(result).toEqual({ data: payload });
     expect(recordCreditDeduction).toHaveBeenCalledWith({
       accountId: "acc_1",
-      creditsToDeduct: 5,
+      creditsToDeduct: 50_000,
       source: "api",
     });
   });
diff --git a/lib/research/__tests__/getResearchTrackStats.test.ts b/lib/research/__tests__/getResearchTrackStats.test.ts
index d5373bc9e..ec883958c 100644
--- a/lib/research/__tests__/getResearchTrackStats.test.ts
+++ b/lib/research/__tests__/getResearchTrackStats.test.ts
@@ -28,7 +28,7 @@ describe("getResearchTrackStats", () => {
     expect(result).toEqual({ data: payload });
     expect(recordCreditDeduction).toHaveBeenCalledWith({
       accountId: "acc_1",
-      creditsToDeduct: 5,
+      creditsToDeduct: 50_000,
       source: "api",
     });
   });
diff --git a/lib/research/__tests__/handleArtistResearch.test.ts b/lib/research/__tests__/handleArtistResearch.test.ts
index a725e56c9..934294222 100644
--- a/lib/research/__tests__/handleArtistResearch.test.ts
+++ b/lib/research/__tests__/handleArtistResearch.test.ts
@@ -55,7 +55,7 @@ describe("handleArtistResearch", () => {
     expect(fetchSongstatsResearch).toHaveBeenCalledWith("/artist/42/albums", undefined);
     expect(recordCreditDeduction).toHaveBeenCalledWith({
       accountId: "acc_1",
-      creditsToDeduct: 5,
+      creditsToDeduct: 50_000,
       source: "api",
     });
     expect(result).toEqual({ data: [{ name: "a" }] });
diff --git a/lib/research/__tests__/handleResearch.test.ts b/lib/research/__tests__/handleResearch.test.ts
index cd03bba49..9da4a62ad 100644
--- a/lib/research/__tests__/handleResearch.test.ts
+++ b/lib/research/__tests__/handleResearch.test.ts
@@ -39,7 +39,7 @@ describe("handleResearch", () => {
     });
     expect(recordCreditDeduction).toHaveBeenCalledWith({
       accountId: "acc_1",
-      creditsToDeduct: 5,
+      creditsToDeduct: 50_000,
       source: "api",
     });
     expect(result).toEqual({ data: [{ id: 1 }] });
diff --git a/lib/research/__tests__/postResearchEventsHandler.test.ts b/lib/research/__tests__/postResearchEventsHandler.test.ts
index 8ef5f5124..9b633f5fb 100644
--- a/lib/research/__tests__/postResearchEventsHandler.test.ts
+++ b/lib/research/__tests__/postResearchEventsHandler.test.ts
@@ -174,7 +174,7 @@ describe("postResearchEventsHandler", () => {
 
     expect(recordCreditDeduction).toHaveBeenCalledWith({
       accountId: "acct-1",
-      creditsToDeduct: 1,
+      creditsToDeduct: 10_000,
       source: "api",
     });
   });
diff --git a/lib/research/__tests__/postResearchWebHandler.test.ts b/lib/research/__tests__/postResearchWebHandler.test.ts
index 112419a91..72e465279 100644
--- a/lib/research/__tests__/postResearchWebHandler.test.ts
+++ b/lib/research/__tests__/postResearchWebHandler.test.ts
@@ -81,7 +81,7 @@ describe("postResearchWebHandler", () => {
     expect(body.results).toEqual(mockResults);
     expect(body.formatted).toBe("# Results\n...");
     expect(recordCreditDeduction).toHaveBeenCalledWith(
-      expect.objectContaining({ accountId: "test-id", creditsToDeduct: 1 }),
+      expect.objectContaining({ accountId: "test-id", creditsToDeduct: 10_000 }),
     );
   });
 });
diff --git a/lib/research/__tests__/validatePostResearchWebRequest.test.ts b/lib/research/__tests__/validatePostResearchWebRequest.test.ts
index 297b28bd9..e8ddf0447 100644
--- a/lib/research/__tests__/validatePostResearchWebRequest.test.ts
+++ b/lib/research/__tests__/validatePostResearchWebRequest.test.ts
@@ -57,7 +57,7 @@ describe("validatePostResearchWebRequest", () => {
   it("gates with exactly 1 credit (web search costs 1, not the research family's 5)", async () => {
     await validatePostResearchWebRequest(req({ query: "x" }));
     expect(ensureCreditsOrShortCircuit).toHaveBeenCalledWith(
-      expect.objectContaining({ accountId: "acct", creditsToDeduct: 1 }),
+      expect.objectContaining({ accountId: "acct", creditsToDeduct: 10_000 }),
     );
   });
 });
diff --git a/lib/research/deductCredits.ts b/lib/research/deductCredits.ts
index 8e98c5667..9e681b26f 100644
--- a/lib/research/deductCredits.ts
+++ b/lib/research/deductCredits.ts
@@ -1,7 +1,9 @@
 import { recordCreditDeduction } from "@/lib/credits/recordCreditDeduction";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 /** Credits charged per successful read-only research call. */
-const RESEARCH_CREDIT_COST = 5;
+const RESEARCH_CREDIT_COST = usdToCredits(PRICES_USD.research);
 
 /**
  * Deduct research credits for a successful read. Failures are logged, never
diff --git a/lib/research/ensureEventsResearchCredits.ts b/lib/research/ensureEventsResearchCredits.ts
index b58c766a4..798393bef 100644
--- a/lib/research/ensureEventsResearchCredits.ts
+++ b/lib/research/ensureEventsResearchCredits.ts
@@ -1,4 +1,6 @@
 import { ensureCreditsOrShortCircuit } from "@/lib/credits/ensureCreditsOrShortCircuit";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 /**
  * Credits charged per artist-events call. Priced at 1 like web search rather
@@ -7,7 +9,7 @@ import { ensureCreditsOrShortCircuit } from "@/lib/credits/ensureCreditsOrShortC
  * sweeps viable — a caller fanning out across a label roster makes one call per
  * artist (chat#1954).
  */
-const EVENTS_RESEARCH_CREDIT_COST = 1;
+const EVENTS_RESEARCH_CREDIT_COST = usdToCredits(PRICES_USD.researchEvents);
 
 /**
  * Per-route credit gate for `POST /api/research/events`. Returns a 402
diff --git a/lib/research/ensureResearchCredits.ts b/lib/research/ensureResearchCredits.ts
index 0e91d719a..157be5e8c 100644
--- a/lib/research/ensureResearchCredits.ts
+++ b/lib/research/ensureResearchCredits.ts
@@ -1,7 +1,9 @@
 import { ensureCreditsOrShortCircuit } from "@/lib/credits/ensureCreditsOrShortCircuit";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 /** Credits charged per read-only research call (artist & non-artist). */
-const RESEARCH_CREDIT_COST = 5;
+const RESEARCH_CREDIT_COST = usdToCredits(PRICES_USD.research);
 
 /**
  * Per-route credit gate for the read-only research family. Each successful
diff --git a/lib/research/ensureWebResearchCredits.ts b/lib/research/ensureWebResearchCredits.ts
index ea089aaf2..1eebeb2af 100644
--- a/lib/research/ensureWebResearchCredits.ts
+++ b/lib/research/ensureWebResearchCredits.ts
@@ -1,4 +1,6 @@
 import { ensureCreditsOrShortCircuit } from "@/lib/credits/ensureCreditsOrShortCircuit";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 /**
  * Credits charged per web-search call. Priced separately from the research
@@ -7,7 +9,7 @@ import { ensureCreditsOrShortCircuit } from "@/lib/credits/ensureCreditsOrShortC
  * (chat#1861). Songstats-backed research endpoints stay on
  * `ensureResearchCredits` at 5.
  */
-const WEB_RESEARCH_CREDIT_COST = 1;
+const WEB_RESEARCH_CREDIT_COST = usdToCredits(PRICES_USD.researchWeb);
 
 /**
  * Per-route credit gate for `POST /api/research/web`. Returns a 402
diff --git a/lib/research/getResearchMetrics.ts b/lib/research/getResearchMetrics.ts
index 5fa2c2aa0..023cfda1e 100644
--- a/lib/research/getResearchMetrics.ts
+++ b/lib/research/getResearchMetrics.ts
@@ -1,6 +1,8 @@
 import { fetchSongstatsResearch } from "@/lib/research/songstats/fetchSongstatsResearch";
 import { resolveArtist } from "@/lib/research/resolveArtist";
 import { recordCreditDeduction } from "@/lib/credits/recordCreditDeduction";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 export type GetResearchMetricsParams = {
   accountId: string;
@@ -31,7 +33,11 @@ export async function getResearchMetrics(
   }
 
   try {
-    await recordCreditDeduction({ accountId: params.accountId, creditsToDeduct: 5, source: "api" });
+    await recordCreditDeduction({
+      accountId: params.accountId,
+      creditsToDeduct: usdToCredits(PRICES_USD.research),
+      source: "api",
+    });
   } catch (error) {
     console.error("[research] credit deduction failed:", error);
   }
diff --git a/lib/research/getResearchTrackHistoricStats.ts b/lib/research/getResearchTrackHistoricStats.ts
index 73b56d63e..ff48d1daa 100644
--- a/lib/research/getResearchTrackHistoricStats.ts
+++ b/lib/research/getResearchTrackHistoricStats.ts
@@ -1,5 +1,7 @@
 import { fetchSongstats } from "@/lib/songstats/fetchSongstats";
 import { recordCreditDeduction } from "@/lib/credits/recordCreditDeduction";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 export type GetResearchTrackHistoricStatsParams = {
   accountId: string;
@@ -27,7 +29,11 @@ export async function getResearchTrackHistoricStats(
   }
 
   try {
-    await recordCreditDeduction({ accountId: params.accountId, creditsToDeduct: 5, source: "api" });
+    await recordCreditDeduction({
+      accountId: params.accountId,
+      creditsToDeduct: usdToCredits(PRICES_USD.research),
+      source: "api",
+    });
   } catch (error) {
     console.error("[research] credit deduction failed:", error);
   }
diff --git a/lib/research/getResearchTrackStats.ts b/lib/research/getResearchTrackStats.ts
index fc925c142..05e3bb234 100644
--- a/lib/research/getResearchTrackStats.ts
+++ b/lib/research/getResearchTrackStats.ts
@@ -1,5 +1,7 @@
 import { fetchSongstats } from "@/lib/songstats/fetchSongstats";
 import { recordCreditDeduction } from "@/lib/credits/recordCreditDeduction";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 export type GetResearchTrackStatsParams = {
   accountId: string;
@@ -24,7 +26,11 @@ export async function getResearchTrackStats(
   }
 
   try {
-    await recordCreditDeduction({ accountId: params.accountId, creditsToDeduct: 5, source: "api" });
+    await recordCreditDeduction({
+      accountId: params.accountId,
+      creditsToDeduct: usdToCredits(PRICES_USD.research),
+      source: "api",
+    });
   } catch (error) {
     console.error("[research] credit deduction failed:", error);
   }
diff --git a/lib/research/handleArtistResearch.ts b/lib/research/handleArtistResearch.ts
index 64efc7ebb..67bacd27b 100644
--- a/lib/research/handleArtistResearch.ts
+++ b/lib/research/handleArtistResearch.ts
@@ -1,6 +1,8 @@
 import { resolveArtist } from "@/lib/research/resolveArtist";
 import { fetchSongstatsResearch } from "@/lib/research/songstats/fetchSongstatsResearch";
 import { recordCreditDeduction } from "@/lib/credits/recordCreditDeduction";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 export type HandleArtistResearchParams = {
   artist: string;
@@ -26,7 +28,14 @@ export type HandleArtistResearchResult = { data: unknown } | { error: string; st
 export async function handleArtistResearch(
   params: HandleArtistResearchParams,
 ): Promise<HandleArtistResearchResult> {
-  const { artist, artistId, accountId, path, query, credits = 5 } = params;
+  const {
+    artist,
+    artistId,
+    accountId,
+    path,
+    query,
+    credits = usdToCredits(PRICES_USD.research),
+  } = params;
 
   const resolved = artistId ? { id: artistId } : await resolveArtist(artist);
   if ("error" in resolved) return { error: resolved.error, status: 404 };
diff --git a/lib/research/handleResearch.ts b/lib/research/handleResearch.ts
index b7913b6e2..f7073c4f8 100644
--- a/lib/research/handleResearch.ts
+++ b/lib/research/handleResearch.ts
@@ -1,5 +1,7 @@
 import { fetchSongstatsResearch } from "@/lib/research/songstats/fetchSongstatsResearch";
 import { recordCreditDeduction } from "@/lib/credits/recordCreditDeduction";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 export type HandleResearchParams = {
   accountId: string;
@@ -23,7 +25,7 @@ export type HandleResearchResult = { data: unknown } | { error: string; status:
  * @returns `{ data }` on success, `{ error, status }` on upstream failure.
  */
 export async function handleResearch(params: HandleResearchParams): Promise<HandleResearchResult> {
-  const { accountId, path, query, credits = 5 } = params;
+  const { accountId, path, query, credits = usdToCredits(PRICES_USD.research) } = params;
 
   const result = await fetchSongstatsResearch(path, query);
   if (result.status !== 200) {
diff --git a/lib/research/postResearchDeepHandler.ts b/lib/research/postResearchDeepHandler.ts
index 3f78be8f1..50f158457 100644
--- a/lib/research/postResearchDeepHandler.ts
+++ b/lib/research/postResearchDeepHandler.ts
@@ -3,6 +3,8 @@ import { getCorsHeaders } from "@/lib/networking/getCorsHeaders";
 import { deductCredits } from "@/lib/credits/deductCredits";
 import { validatePostResearchDeepRequest } from "@/lib/research/validatePostResearchDeepRequest";
 import { chatWithPerplexity } from "@/lib/perplexity/chatWithPerplexity";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 /**
  * Deep research handler — performs comprehensive research via Perplexity sonar-deep-research with citations.
@@ -22,7 +24,7 @@ export async function postResearchDeepHandler(request: NextRequest): Promise<Nex
     );
 
     try {
-      await deductCredits({ accountId, creditsToDeduct: 25 });
+      await deductCredits({ accountId, creditsToDeduct: usdToCredits(PRICES_USD.researchDeep) });
     } catch {
       // Credit deduction failed but data was fetched — log but don't block
     }
diff --git a/lib/research/postResearchEnrichHandler.ts b/lib/research/postResearchEnrichHandler.ts
index 0997190eb..fcad5ff0f 100644
--- a/lib/research/postResearchEnrichHandler.ts
+++ b/lib/research/postResearchEnrichHandler.ts
@@ -5,6 +5,8 @@ import { successResponse } from "@/lib/networking/successResponse";
 import { deductCredits } from "@/lib/credits/deductCredits";
 import { enrichEntity } from "@/lib/parallel/enrichEntity";
 import { validatePostResearchEnrichRequest } from "@/lib/research/validatePostResearchEnrichRequest";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 /**
  * POST /api/research/enrich
@@ -21,8 +23,13 @@ export async function postResearchEnrichHandler(request: NextRequest): Promise<N
     const validated = await validatePostResearchEnrichRequest(request);
     if (validated instanceof NextResponse) return validated;
 
-    const creditCost =
-      validated.processor === "ultra" ? 25 : validated.processor === "core" ? 10 : 5;
+    const creditCost = usdToCredits(
+      validated.processor === "ultra"
+        ? PRICES_USD.researchEnrich.ultra
+        : validated.processor === "core"
+          ? PRICES_USD.researchEnrich.core
+          : PRICES_USD.researchEnrich.base,
+    );
     const result = await enrichEntity(validated.input, validated.schema, validated.processor);
 
     if (result.status === "timeout") {
diff --git a/lib/research/postResearchEventsHandler.ts b/lib/research/postResearchEventsHandler.ts
index c6c6ef6c6..b565cc449 100644
--- a/lib/research/postResearchEventsHandler.ts
+++ b/lib/research/postResearchEventsHandler.ts
@@ -7,6 +7,8 @@ import { getArtistBandsintownId } from "@/lib/research/getArtistBandsintownId";
 import { fetchBandsintownEvents } from "@/lib/apify/bandsintown/fetchBandsintownEvents";
 import { validatePostResearchEventsRequest } from "@/lib/research/validatePostResearchEventsRequest";
 import { isApifyCapacityError } from "@/lib/apify/isApifyCapacityError";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 /**
  * Returned when the artist is reachable but has no Bandsintown profile
@@ -66,7 +68,7 @@ export async function postResearchEventsHandler(request: NextRequest): Promise<N
     try {
       await recordCreditDeduction({
         accountId: validated.accountId,
-        creditsToDeduct: 1,
+        creditsToDeduct: usdToCredits(PRICES_USD.researchEvents),
         source: "api",
       });
     } catch {
diff --git a/lib/research/postResearchExtractHandler.ts b/lib/research/postResearchExtractHandler.ts
index 11eb6ff34..e0dad2b8c 100644
--- a/lib/research/postResearchExtractHandler.ts
+++ b/lib/research/postResearchExtractHandler.ts
@@ -4,6 +4,8 @@ import { successResponse } from "@/lib/networking/successResponse";
 import { deductCredits } from "@/lib/credits/deductCredits";
 import { extractUrl } from "@/lib/parallel/extractUrl";
 import { validatePostResearchExtractRequest } from "@/lib/research/validatePostResearchExtractRequest";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 /**
  * POST /api/research/extract
@@ -19,7 +21,7 @@ export async function postResearchExtractHandler(request: NextRequest): Promise<
     const validated = await validatePostResearchExtractRequest(request);
     if (validated instanceof NextResponse) return validated;
 
-    const creditCost = 5 * validated.urls.length;
+    const creditCost = usdToCredits(PRICES_USD.researchExtractPerUrl) * validated.urls.length;
     const result = await extractUrl(validated.urls, validated.objective, validated.full_content);
 
     try {
diff --git a/lib/research/postResearchPeopleHandler.ts b/lib/research/postResearchPeopleHandler.ts
index 71f4bbec3..b38a566dc 100644
--- a/lib/research/postResearchPeopleHandler.ts
+++ b/lib/research/postResearchPeopleHandler.ts
@@ -4,6 +4,8 @@ import { successResponse } from "@/lib/networking/successResponse";
 import { deductCredits } from "@/lib/credits/deductCredits";
 import { searchPeople } from "@/lib/exa/searchPeople";
 import { validatePostResearchPeopleRequest } from "@/lib/research/validatePostResearchPeopleRequest";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 /**
  * POST /api/research/people
@@ -22,7 +24,10 @@ export async function postResearchPeopleHandler(request: NextRequest): Promise<N
     const result = await searchPeople(validated.query, validated.num_results ?? 10);
 
     try {
-      await deductCredits({ accountId: validated.accountId, creditsToDeduct: 5 });
+      await deductCredits({
+        accountId: validated.accountId,
+        creditsToDeduct: usdToCredits(PRICES_USD.researchPeople),
+      });
     } catch {
       // Credit deduction failed but data was fetched — log but don't block
     }
diff --git a/lib/research/postResearchWebHandler.ts b/lib/research/postResearchWebHandler.ts
index c77620a99..49871e017 100644
--- a/lib/research/postResearchWebHandler.ts
+++ b/lib/research/postResearchWebHandler.ts
@@ -5,6 +5,8 @@ import { recordCreditDeduction } from "@/lib/credits/recordCreditDeduction";
 import { searchPerplexity } from "@/lib/perplexity/searchPerplexity";
 import { formatSearchResultsAsMarkdown } from "@/lib/perplexity/formatSearchResultsAsMarkdown";
 import { validatePostResearchWebRequest } from "@/lib/research/validatePostResearchWebRequest";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 /**
  * Web search handler — queries Perplexity for real-time web results with formatted markdown output.
@@ -28,7 +30,7 @@ export async function postResearchWebHandler(request: NextRequest): Promise<Next
     try {
       await recordCreditDeduction({
         accountId: validated.accountId,
-        creditsToDeduct: 1,
+        creditsToDeduct: usdToCredits(PRICES_USD.researchWeb),
         source: "api",
       });
     } catch {
diff --git a/lib/research/validatePostResearchDeepRequest.ts b/lib/research/validatePostResearchDeepRequest.ts
index 5a6ef6b5e..1795e5778 100644
--- a/lib/research/validatePostResearchDeepRequest.ts
+++ b/lib/research/validatePostResearchDeepRequest.ts
@@ -3,6 +3,8 @@ import { z } from "zod";
 import { validateAuthContext } from "@/lib/auth/validateAuthContext";
 import { ensureCreditsOrShortCircuit } from "@/lib/credits/ensureCreditsOrShortCircuit";
 import { errorResponse } from "@/lib/networking/errorResponse";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 const bodySchema = z.object({
   query: z.string().min(1, "query is required"),
@@ -32,7 +34,7 @@ export async function validatePostResearchDeepRequest(
 
   const short = await ensureCreditsOrShortCircuit({
     accountId: authResult.accountId,
-    creditsToDeduct: 25,
+    creditsToDeduct: usdToCredits(PRICES_USD.researchDeep),
   });
   if (short) return short;
 
diff --git a/lib/research/validatePostResearchEnrichRequest.ts b/lib/research/validatePostResearchEnrichRequest.ts
index f8031532f..f8c8bd502 100644
--- a/lib/research/validatePostResearchEnrichRequest.ts
+++ b/lib/research/validatePostResearchEnrichRequest.ts
@@ -3,6 +3,8 @@ import { z } from "zod";
 import { validateAuthContext } from "@/lib/auth/validateAuthContext";
 import { ensureCreditsOrShortCircuit } from "@/lib/credits/ensureCreditsOrShortCircuit";
 import { errorResponse } from "@/lib/networking/errorResponse";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 const bodySchema = z.object({
   input: z.string().min(1, "input is required"),
@@ -33,8 +35,13 @@ export async function validatePostResearchEnrichRequest(
     return errorResponse(parsed.error.issues[0]?.message ?? "Invalid request body", 400);
   }
 
-  const creditCost =
-    parsed.data.processor === "ultra" ? 25 : parsed.data.processor === "core" ? 10 : 5;
+  const creditCost = usdToCredits(
+    parsed.data.processor === "ultra"
+      ? PRICES_USD.researchEnrich.ultra
+      : parsed.data.processor === "core"
+        ? PRICES_USD.researchEnrich.core
+        : PRICES_USD.researchEnrich.base,
+  );
   const short = await ensureCreditsOrShortCircuit({
     accountId: authResult.accountId,
     creditsToDeduct: creditCost,
diff --git a/lib/research/validatePostResearchExtractRequest.ts b/lib/research/validatePostResearchExtractRequest.ts
index 17418ea70..785147199 100644
--- a/lib/research/validatePostResearchExtractRequest.ts
+++ b/lib/research/validatePostResearchExtractRequest.ts
@@ -3,6 +3,8 @@ import { z } from "zod";
 import { validateAuthContext } from "@/lib/auth/validateAuthContext";
 import { ensureCreditsOrShortCircuit } from "@/lib/credits/ensureCreditsOrShortCircuit";
 import { errorResponse } from "@/lib/networking/errorResponse";
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
 
 const bodySchema = z.object({
   urls: z.array(z.string().min(1)).min(1).max(10),
@@ -35,7 +37,7 @@ export async function validatePostResearchExtractRequest(
 
   const short = await ensureCreditsOrShortCircuit({
     accountId: authResult.accountId,
-    creditsToDeduct: 5 * parsed.data.urls.length,
+    creditsToDeduct: usdToCredits(PRICES_USD.researchExtractPerUrl) * parsed.data.urls.length,
   });
   if (short) return short;
 
diff --git a/lib/socials/__tests__/deductSocialScrapeCredits.test.ts b/lib/socials/__tests__/deductSocialScrapeCredits.test.ts
index 7e9656510..7448f2f12 100644
--- a/lib/socials/__tests__/deductSocialScrapeCredits.test.ts
+++ b/lib/socials/__tests__/deductSocialScrapeCredits.test.ts
@@ -13,16 +13,16 @@ describe("deductSocialScrapeCredits", () => {
   });
 
   it("records the deduction with the given credits", async () => {
-    await deductSocialScrapeCredits(ACCOUNT_ID, 25);
+    await deductSocialScrapeCredits(ACCOUNT_ID, 250_000);
     expect(recordCreditDeduction).toHaveBeenCalledWith({
       accountId: ACCOUNT_ID,
-      creditsToDeduct: 25,
+      creditsToDeduct: 250_000,
       source: "api",
     });
   });
 
   it("never throws when the deduction fails (billing must not fail a started scrape)", async () => {
     vi.mocked(recordCreditDeduction).mockRejectedValue(new Error("db down"));
-    await expect(deductSocialScrapeCredits(ACCOUNT_ID, 5)).resolves.toBeUndefined();
+    await expect(deductSocialScrapeCredits(ACCOUNT_ID, 50_000)).resolves.toBeUndefined();
   });
 });
diff --git a/lib/socials/__tests__/ensureSocialScrapeCredits.test.ts b/lib/socials/__tests__/ensureSocialScrapeCredits.test.ts
index 01ecddf93..822b6110c 100644
--- a/lib/socials/__tests__/ensureSocialScrapeCredits.test.ts
+++ b/lib/socials/__tests__/ensureSocialScrapeCredits.test.ts
@@ -17,15 +17,15 @@ describe("ensureSocialScrapeCredits", () => {
   });
 
   it("gates on the given credit amount", async () => {
-    expect(await ensureSocialScrapeCredits(ACCOUNT_ID, 25)).toBeNull();
+    expect(await ensureSocialScrapeCredits(ACCOUNT_ID, 250_000)).toBeNull();
     expect(ensureCreditsOrShortCircuit).toHaveBeenCalledWith(
-      expect.objectContaining({ accountId: ACCOUNT_ID, creditsToDeduct: 25 }),
+      expect.objectContaining({ accountId: ACCOUNT_ID, creditsToDeduct: 250_000 }),
     );
   });
 
   it("passes through the 402 short-circuit response", async () => {
     const short = NextResponse.json({}, { status: 402 });
     vi.mocked(ensureCreditsOrShortCircuit).mockResolvedValue(short);
-    expect(await ensureSocialScrapeCredits(ACCOUNT_ID, 5)).toBe(short);
+    expect(await ensureSocialScrapeCredits(ACCOUNT_ID, 50_000)).toBe(short);
   });
 });
diff --git a/lib/socials/__tests__/getSocialScrapeCreditCost.test.ts b/lib/socials/__tests__/getSocialScrapeCreditCost.test.ts
index bd4a5d9c6..6b5db7919 100644
--- a/lib/socials/__tests__/getSocialScrapeCreditCost.test.ts
+++ b/lib/socials/__tests__/getSocialScrapeCreditCost.test.ts
@@ -4,12 +4,12 @@ import { getSocialScrapeCreditCost } from "../getSocialScrapeCreditCost";
 
 describe("getSocialScrapeCreditCost", () => {
   it("charges the 5-credit base when posts is omitted", () => {
-    expect(getSocialScrapeCreditCost(undefined)).toBe(5);
+    expect(getSocialScrapeCreditCost(undefined)).toBe(50_000);
   });
 
   it("charges 5 + posts when a depth is requested", () => {
-    expect(getSocialScrapeCreditCost(1)).toBe(6);
-    expect(getSocialScrapeCreditCost(20)).toBe(25);
-    expect(getSocialScrapeCreditCost(100)).toBe(105);
+    expect(getSocialScrapeCreditCost(1)).toBe(60_000);
+    expect(getSocialScrapeCreditCost(20)).toBe(250_000);
+    expect(getSocialScrapeCreditCost(100)).toBe(1_050_000);
   });
 });
diff --git a/lib/socials/__tests__/postSocialScrapeHandler.test.ts b/lib/socials/__tests__/postSocialScrapeHandler.test.ts
index c645aa2c2..2c6c014bc 100644
--- a/lib/socials/__tests__/postSocialScrapeHandler.test.ts
+++ b/lib/socials/__tests__/postSocialScrapeHandler.test.ts
@@ -43,16 +43,16 @@ describe("postSocialScrapeHandler", () => {
     expect(res.status).toBe(404);
   });
 
-  it("returns 200 with { runId, datasetId } on success and deducts the base 5 credits", async () => {
+  it("returns 200 with { runId, datasetId } on success and deducts the base $0.05", async () => {
     vi.mocked(scrapeProfileUrl).mockResolvedValue({ runId: "r1", datasetId: "d1" } as never);
     const res = await postSocialScrapeHandler(request, SOCIAL_ID);
     expect(res.status).toBe(200);
     expect(await res.json()).toEqual({ runId: "r1", datasetId: "d1" });
     expect(scrapeProfileUrl).toHaveBeenCalledWith(social.profile_url, social.username, undefined);
-    expect(deductSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 5);
+    expect(deductSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 50_000);
   });
 
-  it("forwards validated posts to scrapeProfileUrl and deducts 5 + posts credits", async () => {
+  it("forwards validated posts to scrapeProfileUrl and deducts $0.05 + $0.01 per post", async () => {
     vi.mocked(validatePostSocialScrapeRequest).mockResolvedValue({
       social_id: SOCIAL_ID,
       account_id: ACCOUNT_ID,
@@ -61,7 +61,7 @@ describe("postSocialScrapeHandler", () => {
     vi.mocked(scrapeProfileUrl).mockResolvedValue({ runId: "r1", datasetId: "d1" } as never);
     await postSocialScrapeHandler(request, SOCIAL_ID);
     expect(scrapeProfileUrl).toHaveBeenCalledWith(social.profile_url, social.username, 20);
-    expect(deductSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 25);
+    expect(deductSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 250_000);
   });
 
   it("does not deduct credits when the scrape fails to start", async () => {
diff --git a/lib/socials/__tests__/validatePostSocialScrapeRequest.test.ts b/lib/socials/__tests__/validatePostSocialScrapeRequest.test.ts
index ded2f4ec9..533b97338 100644
--- a/lib/socials/__tests__/validatePostSocialScrapeRequest.test.ts
+++ b/lib/socials/__tests__/validatePostSocialScrapeRequest.test.ts
@@ -79,10 +79,10 @@ describe("validatePostSocialScrapeRequest", () => {
       posts: undefined,
       account_id: ACCOUNT_ID,
     });
-    expect(ensureSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 5);
+    expect(ensureSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 50_000);
   });
 
-  it("parses a valid posts query param and gates on 5 + posts credits", async () => {
+  it("parses a valid posts query param and gates on $0.05 + $0.01 per post", async () => {
     const req = new NextRequest(`http://localhost/api/socials/${SOCIAL_ID}/scrape?posts=20`, {
       method: "POST",
       headers: { "x-api-key": "k" },
@@ -92,7 +92,7 @@ describe("validatePostSocialScrapeRequest", () => {
       posts: 20,
       account_id: ACCOUNT_ID,
     });
-    expect(ensureSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 25);
+    expect(ensureSocialScrapeCredits).toHaveBeenCalledWith(ACCOUNT_ID, 250_000);
   });
 
   it("short-circuits with the 402 when credits are insufficient", async () => {
diff --git a/lib/socials/getSocialScrapeCreditCost.ts b/lib/socials/getSocialScrapeCreditCost.ts
index 46cc5e277..ed5fe7b26 100644
--- a/lib/socials/getSocialScrapeCreditCost.ts
+++ b/lib/socials/getSocialScrapeCreditCost.ts
@@ -1,5 +1,8 @@
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+import { PRICES_USD } from "@/lib/credits/pricesUsd";
+
 /** Base credits charged per social scrape (matches the research family's flat rate). */
-export const SOCIAL_SCRAPE_BASE_CREDIT_COST = 5;
+export const SOCIAL_SCRAPE_BASE_CREDIT_COST = usdToCredits(PRICES_USD.socialScrapeBase);
 
 /**
  * Credits for one profile scrape: 5 base + 1 per requested post. Priced from
@@ -8,5 +11,7 @@ export const SOCIAL_SCRAPE_BASE_CREDIT_COST = 5;
  * keeps ≥1.75× margin at posts=100 while staying one rule for every platform.
  */
 export function getSocialScrapeCreditCost(posts?: number): number {
-  return SOCIAL_SCRAPE_BASE_CREDIT_COST + (posts ?? 0);
+  return (
+    SOCIAL_SCRAPE_BASE_CREDIT_COST + (posts ?? 0) * usdToCredits(PRICES_USD.socialScrapePerPost)
+  );
 }
diff --git a/lib/stripe/__tests__/computeCreditsTopupCharge.test.ts b/lib/stripe/__tests__/computeCreditsTopupCharge.test.ts
index 7e0b2c457..7d548bbd3 100644
--- a/lib/stripe/__tests__/computeCreditsTopupCharge.test.ts
+++ b/lib/stripe/__tests__/computeCreditsTopupCharge.test.ts
@@ -1,29 +1,33 @@
 import { describe, it, expect } from "vitest";
+import { creditsToStripeCents } from "@/lib/credits/creditsToStripeCents";
 import { computeCreditsTopupCharge } from "@/lib/stripe/computeCreditsTopupCharge";
 
 describe("computeCreditsTopupCharge", () => {
   it("grosses up so net (after Stripe US card fee 2.9% + 30¢) covers credits", () => {
-    // For 250 credits: gross-up math is ceil((250 + 30) / (1 - 0.029)) = ceil(288.36) = 289¢
+    // For 2,500,000 credits ($2.50 = 250¢): gross-up math is ceil((250 + 30) / (1 - 0.029)) = ceil(288.36) = 289¢
     // → fee = 289 - 250 = 39¢, customer charged $2.89, Stripe takes ~38.4¢, business nets ≥ 250¢
-    const { feeCents, totalCents } = computeCreditsTopupCharge(250);
+    const { feeCents, totalCents } = computeCreditsTopupCharge(2_500_000);
     expect(totalCents).toBe(289);
     expect(feeCents).toBe(39);
   });
 
   it("nets at least credits cents after Stripe's actual fee for a range of sizes", () => {
-    for (const credits of [1, 50, 100, 250, 1_000, 10_000, 100_000]) {
+    for (const credits of [
+      10_000, 500_000, 1_000_000, 2_500_000, 10_000_000, 100_000_000, 1_000_000_000,
+    ]) {
       const { totalCents } = computeCreditsTopupCharge(credits);
       const stripeFee = totalCents * 0.029 + 30;
+      const credits_cents = credits / 10_000;
       const net = totalCents - stripeFee;
       // allow 1¢ rounding slack — gross-up rounds up so we never undercollect
-      expect(net).toBeGreaterThanOrEqual(credits - 0.5);
+      expect(net).toBeGreaterThanOrEqual(credits_cents - 0.5);
     }
   });
 
-  it("totalCents = credits + feeCents", () => {
-    for (const credits of [1, 17, 250, 9999]) {
+  it("totalCents = the credits' cents + feeCents", () => {
+    for (const credits of [10_000, 170_000, 2_500_000, 99_990_000]) {
       const { feeCents, totalCents } = computeCreditsTopupCharge(credits);
-      expect(totalCents).toBe(credits + feeCents);
+      expect(totalCents).toBe(creditsToStripeCents(credits) + feeCents);
     }
   });
 
diff --git a/lib/stripe/__tests__/createCreditsSessionHandler.test.ts b/lib/stripe/__tests__/createCreditsSessionHandler.test.ts
index dc51a5723..e396cc42f 100644
--- a/lib/stripe/__tests__/createCreditsSessionHandler.test.ts
+++ b/lib/stripe/__tests__/createCreditsSessionHandler.test.ts
@@ -36,7 +36,7 @@ describe("createCreditsSessionHandler — auth, auto-charge, and 5xx paths", ()
     expect(res.status).toBe(200);
     await expect(res.json()).resolves.toEqual({
       paymentIntentId: "pi_ok",
-      creditsPurchased: 250,
+      creditsPurchased: 2_500_000,
       totalCents: 289,
     });
     expect(createCreditsStripeSession).not.toHaveBeenCalled();
diff --git a/lib/stripe/__tests__/createCreditsSessionHandlerTestMocks.ts b/lib/stripe/__tests__/createCreditsSessionHandlerTestMocks.ts
index 2d7a996f8..e8c79a54d 100644
--- a/lib/stripe/__tests__/createCreditsSessionHandlerTestMocks.ts
+++ b/lib/stripe/__tests__/createCreditsSessionHandlerTestMocks.ts
@@ -20,5 +20,5 @@ export const ACCOUNT = "123e4567-e89b-12d3-a456-426614174000";
 export const validated = {
   accountId: ACCOUNT,
   successUrl: "https://chat.recoupable.com/ok",
-  credits: 250,
+  credits: 2_500_000,
 };
diff --git a/lib/stripe/__tests__/createCreditsSessionSchemas.test.ts b/lib/stripe/__tests__/createCreditsSessionSchemas.test.ts
index d6db5de55..fff8f23d2 100644
--- a/lib/stripe/__tests__/createCreditsSessionSchemas.test.ts
+++ b/lib/stripe/__tests__/createCreditsSessionSchemas.test.ts
@@ -3,14 +3,14 @@ import { createCreditsSessionBodySchema } from "@/lib/stripe/createCreditsSessio
 
 describe("createCreditsSessionBodySchema", () => {
   it("requires successUrl", () => {
-    const r = createCreditsSessionBodySchema.safeParse({ credits: 100 });
+    const r = createCreditsSessionBodySchema.safeParse({ credits: 1_000_000 });
     expect(r.success).toBe(false);
   });
 
   it("rejects invalid URL", () => {
     const r = createCreditsSessionBodySchema.safeParse({
       successUrl: "not-a-url",
-      credits: 100,
+      credits: 1_000_000,
     });
     expect(r.success).toBe(false);
   });
@@ -30,6 +30,15 @@ describe("createCreditsSessionBodySchema", () => {
     expect(r.success).toBe(false);
   });
 
+  it("rejects credits that are not a whole number of cents", () => {
+    // Stripe bills whole cents: at six decimals a cent is 10,000 credits.
+    const r = createCreditsSessionBodySchema.safeParse({
+      successUrl: "https://chat.recoupable.com/done",
+      credits: 250,
+    });
+    expect(r.success).toBe(false);
+  });
+
   it("rejects credits < 1", () => {
     const r = createCreditsSessionBodySchema.safeParse({
       successUrl: "https://chat.recoupable.com/done",
@@ -49,13 +58,13 @@ describe("createCreditsSessionBodySchema", () => {
   it("accepts successUrl + credits", () => {
     const r = createCreditsSessionBodySchema.safeParse({
       successUrl: "https://chat.recoupable.com/done",
-      credits: 250,
+      credits: 2_500_000,
     });
     expect(r.success).toBe(true);
     if (r.success) {
       expect(r.data).toEqual({
         successUrl: "https://chat.recoupable.com/done",
-        credits: 250,
+        credits: 2_500_000,
       });
     }
   });
@@ -63,7 +72,7 @@ describe("createCreditsSessionBodySchema", () => {
   it("accepts optional accountId UUID", () => {
     const r = createCreditsSessionBodySchema.safeParse({
       successUrl: "https://chat.recoupable.com/done",
-      credits: 250,
+      credits: 2_500_000,
       accountId: "123e4567-e89b-12d3-a456-426614174000",
     });
     expect(r.success).toBe(true);
@@ -72,7 +81,7 @@ describe("createCreditsSessionBodySchema", () => {
   it("rejects malformed accountId", () => {
     const r = createCreditsSessionBodySchema.safeParse({
       successUrl: "https://chat.recoupable.com/done",
-      credits: 250,
+      credits: 2_500_000,
       accountId: "not-a-uuid",
     });
     expect(r.success).toBe(false);
@@ -81,7 +90,7 @@ describe("createCreditsSessionBodySchema", () => {
   it("rejects unknown keys (strict)", () => {
     const r = createCreditsSessionBodySchema.safeParse({
       successUrl: "https://chat.recoupable.com/done",
-      credits: 250,
+      credits: 2_500_000,
       extra: true,
     });
     expect(r.success).toBe(false);
diff --git a/lib/stripe/__tests__/createCreditsStripeSession.test.ts b/lib/stripe/__tests__/createCreditsStripeSession.test.ts
index c21d9f824..75c004c73 100644
--- a/lib/stripe/__tests__/createCreditsStripeSession.test.ts
+++ b/lib/stripe/__tests__/createCreditsStripeSession.test.ts
@@ -20,25 +20,25 @@ describe("createCreditsStripeSession", () => {
     });
   });
 
-  it("creates a one-time payment checkout with two line items: credits @ 1¢ + processing fee", async () => {
+  it("creates a one-time payment checkout with two line items: credits as whole cents + processing fee", async () => {
     await createCreditsStripeSession({
       accountId: "acc-1",
-      credits: 250,
+      credits: 2_500_000,
       successUrl: "https://example.com/success",
       customer: "cus_acc1",
     });
 
-    // For 250 credits: gross-up math is ceil((250 + 30) / 0.971) = 289¢, so fee = 39¢
+    // For 2,500,000 credits ($2.50): gross-up math is ceil((250 + 30) / 0.971) = 289¢, so fee = 39¢
     expect(checkoutSessionsCreate).toHaveBeenCalledWith({
       customer: "cus_acc1",
       line_items: [
         {
           price_data: {
             currency: "usd",
-            unit_amount: 1,
+            unit_amount: 250,
             product_data: { name: "Recoup credits" },
           },
-          quantity: 250,
+          quantity: 1,
         },
         {
           price_data: {
@@ -53,14 +53,14 @@ describe("createCreditsStripeSession", () => {
       client_reference_id: "acc-1",
       metadata: {
         accountId: "acc-1",
-        credits: "250",
+        credits: "2500000",
         purpose: "credits_topup",
       },
       payment_intent_data: {
         setup_future_usage: "off_session",
         metadata: {
           accountId: "acc-1",
-          credits: "250",
+          credits: "2500000",
           purpose: "credits_topup",
           paymentMethod: "checkout",
         },
diff --git a/lib/stripe/__tests__/validateCreateCreditsSessionRequest.auth.test.ts b/lib/stripe/__tests__/validateCreateCreditsSessionRequest.auth.test.ts
index d40f79c7b..68af517f9 100644
--- a/lib/stripe/__tests__/validateCreateCreditsSessionRequest.auth.test.ts
+++ b/lib/stripe/__tests__/validateCreateCreditsSessionRequest.auth.test.ts
@@ -30,7 +30,7 @@ describe("validateCreateCreditsSessionRequest — auth + happy path", () => {
     const req = new NextRequest(URL, {
       method: "POST",
       headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({ successUrl: "https://chat.recoupable.com/done", credits: 100 }),
+      body: JSON.stringify({ successUrl: "https://chat.recoupable.com/done", credits: 1_000_000 }),
     });
     const res = await validateCreateCreditsSessionRequest(req);
     expect((res as NextResponse).status).toBe(401);
@@ -48,12 +48,12 @@ describe("validateCreateCreditsSessionRequest — auth + happy path", () => {
     const req = new NextRequest(URL, {
       method: "POST",
       headers: { "Content-Type": "application/json", "x-api-key": "k" },
-      body: JSON.stringify({ successUrl: "https://chat.recoupable.com/done", credits: 250 }),
+      body: JSON.stringify({ successUrl: "https://chat.recoupable.com/done", credits: 2_500_000 }),
     });
     expect(await validateCreateCreditsSessionRequest(req)).toEqual({
       accountId: ACCOUNT,
       successUrl: "https://chat.recoupable.com/done",
-      credits: 250,
+      credits: 2_500_000,
     });
     expect(validateAuthContext).toHaveBeenCalledWith(req, { accountId: undefined });
   });
@@ -69,14 +69,14 @@ describe("validateCreateCreditsSessionRequest — auth + happy path", () => {
       headers: { "Content-Type": "application/json", "x-api-key": "k" },
       body: JSON.stringify({
         successUrl: "https://chat.recoupable.com/done",
-        credits: 100,
+        credits: 1_000_000,
         accountId: ADMIN,
       }),
     });
     expect(await validateCreateCreditsSessionRequest(req)).toEqual({
       accountId: ADMIN,
       successUrl: "https://chat.recoupable.com/done",
-      credits: 100,
+      credits: 1_000_000,
     });
     expect(validateAuthContext).toHaveBeenCalledWith(req, { accountId: ADMIN });
   });
diff --git a/lib/stripe/__tests__/validateCreateCreditsSessionRequest.body.test.ts b/lib/stripe/__tests__/validateCreateCreditsSessionRequest.body.test.ts
index c8ce6306b..8a3f8972a 100644
--- a/lib/stripe/__tests__/validateCreateCreditsSessionRequest.body.test.ts
+++ b/lib/stripe/__tests__/validateCreateCreditsSessionRequest.body.test.ts
@@ -17,7 +17,7 @@ const HEADERS = { "Content-Type": "application/json", "x-api-key": "k" };
 const body = (overrides: Record<string, unknown> = {}) =>
   JSON.stringify({
     successUrl: "https://chat.recoupable.com/done",
-    credits: 250,
+    credits: 2_500_000,
     ...overrides,
   });
 
@@ -34,11 +34,12 @@ describe("validateCreateCreditsSessionRequest — body validation", () => {
   });
 
   it.each([
-    ["missing successUrl", JSON.stringify({ credits: 100 })],
+    ["missing successUrl", JSON.stringify({ credits: 1_000_000 })],
     ["missing credits", JSON.stringify({ successUrl: "https://chat.recoupable.com/done" })],
     ["credits = 0", body({ credits: 0 })],
     ["credits = -5", body({ credits: -5 })],
     ["credits = 12.5", body({ credits: 12.5 })],
+    ["credits = 250 (not a whole number of cents)", body({ credits: 250 })],
     ["malformed successUrl", body({ successUrl: "not-a-url" })],
     ["bad accountId UUID", body({ accountId: "not-a-uuid" })],
     ["unknown body key (strict)", body({ extra: true })],
diff --git a/lib/stripe/computeCreditsTopupCharge.ts b/lib/stripe/computeCreditsTopupCharge.ts
index 2fac1c0fe..4cedd10cb 100644
--- a/lib/stripe/computeCreditsTopupCharge.ts
+++ b/lib/stripe/computeCreditsTopupCharge.ts
@@ -1,4 +1,5 @@
 import { STRIPE_CARD_FEE_FIXED_CENTS, STRIPE_CARD_FEE_PERCENTAGE } from "@/lib/stripe/config";
+import { creditsToStripeCents } from "@/lib/credits/creditsToStripeCents";
 
 export interface CreditsTopupCharge {
   /** Processing fee in cents (Stripe US card pricing). */
@@ -22,8 +23,9 @@ export function computeCreditsTopupCharge(credits: number): CreditsTopupCharge {
     throw new Error("credits must be a positive integer");
   }
 
+  const amountCents = creditsToStripeCents(credits);
   const totalCents = Math.ceil(
-    (credits + STRIPE_CARD_FEE_FIXED_CENTS) / (1 - STRIPE_CARD_FEE_PERCENTAGE),
+    (amountCents + STRIPE_CARD_FEE_FIXED_CENTS) / (1 - STRIPE_CARD_FEE_PERCENTAGE),
   );
-  return { feeCents: totalCents - credits, totalCents };
+  return { feeCents: totalCents - amountCents, totalCents };
 }
diff --git a/lib/stripe/createCreditsSessionSchemas.ts b/lib/stripe/createCreditsSessionSchemas.ts
index bcef9befb..85ad46b5e 100644
--- a/lib/stripe/createCreditsSessionSchemas.ts
+++ b/lib/stripe/createCreditsSessionSchemas.ts
@@ -1,12 +1,20 @@
+import { CREDIT_DECIMALS } from "@/lib/credits/creditDecimals";
 import { z } from "zod";
 
+/** Stripe bills whole cents, so a top-up must be a whole number of them. */
+const CREDITS_PER_CENT = 10 ** (CREDIT_DECIMALS - 2);
+
 export const createCreditsSessionBodySchema = z
   .object({
     successUrl: z.string().min(1, "successUrl is required").url("successUrl must be a valid URL"),
     credits: z
       .number({ message: "credits is required" })
       .int("credits must be an integer")
-      .min(1, "credits must be a positive integer"),
+      .min(1, "credits must be a positive integer")
+      .multipleOf(
+        CREDITS_PER_CENT,
+        `credits must be a whole number of cents (a multiple of ${CREDITS_PER_CENT})`,
+      ),
     accountId: z.string().uuid("accountId must be a valid UUID").optional(),
   })
   .strict();
diff --git a/lib/stripe/createCreditsStripeSession.ts b/lib/stripe/createCreditsStripeSession.ts
index 40ca5112a..ff4c93771 100644
--- a/lib/stripe/createCreditsStripeSession.ts
+++ b/lib/stripe/createCreditsStripeSession.ts
@@ -2,11 +2,12 @@ import type Stripe from "stripe";
 import stripeClient from "@/lib/stripe/client";
 import { CREDIT_TOPUP_PURPOSE } from "@/lib/stripe/creditsTopupPurpose";
 import { computeCreditsTopupCharge } from "@/lib/stripe/computeCreditsTopupCharge";
+import { creditsToStripeCents } from "@/lib/credits/creditsToStripeCents";
 
 /**
- * One credit equals one US cent ($0.01). Total charge = unit_amount * credits.
+ * Credits are micro-dollars; the line item is their whole-cent USD value
+ * (`creditsToStripeCents`), quantity 1, plus the processing fee.
  */
-const UNIT_AMOUNT_CENTS_PER_CREDIT = 1;
 
 interface CreateCreditsStripeSessionParams {
   accountId: string;
@@ -51,10 +52,10 @@ export async function createCreditsStripeSession({
       {
         price_data: {
           currency: "usd",
-          unit_amount: UNIT_AMOUNT_CENTS_PER_CREDIT,
+          unit_amount: creditsToStripeCents(credits),
           product_data: { name: "Recoup credits" },
         },
-        quantity: credits,
+        quantity: 1,
       },
       {
         price_data: {
diff --git a/lib/x402/getCreditsForPrice.ts b/lib/x402/getCreditsForPrice.ts
index 14a752d81..b30392266 100644
--- a/lib/x402/getCreditsForPrice.ts
+++ b/lib/x402/getCreditsForPrice.ts
@@ -1,3 +1,5 @@
+import { usdToCredits } from "@/lib/credits/usdToCredits";
+
 /**
  * Converts a price string to the number of credits required.
  * 1 credit = $0.01, rounded up to the nearest credit.
@@ -11,6 +13,5 @@ export function getCreditsForPrice(price: string): number {
   if (isNaN(priceNumber) || priceNumber <= 0) {
     throw new Error(`Invalid price string: ${price}`);
   }
-  const credits = Math.ceil(priceNumber / 0.01);
-  return credits;
+  return usdToCredits(priceNumber);
 }