ScrawnDotDev · thedevyashsaini · May 28, 2026 · May 28, 2026 · May 28, 2026 · May 28, 2026
diff --git a/README.md b/README.md
@@ -38,6 +38,6 @@ const biller = scrawn({
 // Track a billable event
 await biller.sdkCallEventConsumer({
   userId: "user-123",
-  debitAmount: 100,
+  debit: 100,
 });
 ```
diff --git a/examples/ai-sdk-wrapper-usage.ts b/examples/ai-sdk-wrapper-usage.ts
@@ -6,8 +6,8 @@ config({ path: ".env.local" });
 
 async function main() {
   const aii = biller.ai(ai, {
-    inputDebit: { tag: "PREMIUM_CALL" },
-    outputDebit: { tag: "EXTRA_FEE" },
+    inputDebit: biller.tag("PREMIUM_CALL"),
+    outputDebit: biller.expr("COMPLEX_FEE"),
   });
 
   const result = await aii.streamText({

diff --git a/examples/ai-token-stream-expr-usage.ts b/examples/ai-token-stream-expr-usage.ts
@@ -18,23 +18,17 @@ async function* tokenUsageFromAIStream(): AsyncGenerator<
     model: "gpt-4",
     inputTokens: 150,
     outputTokens: 0,
-    inputDebit: { expr: biller.expr("PER_TOKEN_INPUT") },
-    outputDebit: {
-      expr: biller.expr(mul(biller.tag("EXTRA_FEE"), outputTokens())),
-    },
+    inputDebit: biller.expr("PER_TOKEN_INPUT"),
+    outputDebit: mul(biller.tag("EXTRA_FEE"), outputTokens()),
   };
 
   yield {
     userId,
     model: "gpt-4",
     inputTokens: 0,
     outputTokens: 75,
-    inputDebit: {
-      expr: biller.expr(mul(biller.tag("PREMIUM_CALL"), inputTokens())),
-    },
-    outputDebit: {
-      expr: biller.expr(mul(biller.tag("EXTRA_FEE"), outputTokens())),
-    },
+    inputDebit: mul(biller.tag("PREMIUM_CALL"), inputTokens()),
+    outputDebit: mul(biller.tag("EXTRA_FEE"), outputTokens()),
   };
 }
 

diff --git a/examples/ai-token-stream-usage.ts b/examples/ai-token-stream-usage.ts
@@ -9,8 +9,8 @@ async function* tokenUsageFromAIStream() {
     model: "gpt-4",
     inputTokens: 150,
     outputTokens: 0,
-    inputDebit: { amount: 1 },
-    outputDebit: { amount: 0 },
+    inputDebit: 1,
+    outputDebit: 0,
   };
 
   // Output tokens as they stream
@@ -19,8 +19,8 @@ async function* tokenUsageFromAIStream() {
     model: "gpt-4",
     inputTokens: 0,
     outputTokens: 75,
-    inputDebit: { amount: 0 },
-    outputDebit: { amount: 1 },
+    inputDebit: 0,
+    outputDebit: 1,
   };
 }
 

diff --git a/examples/basic-usage-expr.ts b/examples/basic-usage-expr.ts
@@ -6,19 +6,17 @@ config({ path: ".env.local" });
 async function main() {
   await biller.basicUsageEventConsumer({
     userId: "c0971bcb-b901-4c3e-a191-c9a97871c39f",
-    debitExpr: biller.expr(mul(biller.tag("PREMIUM_CALL"), 3)),
+    debit: mul(biller.tag("PREMIUM_CALL"), 3),
   });
 
   await biller.basicUsageEventConsumer({
     userId: "c0971bcb-b901-4c3e-a191-c9a97871c39f",
-    debitExpr: biller.expr(mul(biller.tag("EXTRA_FEE"), 3)),
+    debit: mul(biller.tag("EXTRA_FEE"), 3),
   });
 
   await biller.basicUsageEventConsumer({
     userId: "c0971bcb-b901-4c3e-a191-c9a97871c39f",
-    debitExpr: biller.expr(
-      add(biller.expr("COMPLEX_FEE"), mul(biller.tag("PREMIUM_CALL"), 5))
-    ),
+    debit: add(biller.expr("COMPLEX_FEE"), mul(biller.tag("PREMIUM_CALL"), 5)),
   });
 
   console.log("Basic usage expression events consumed successfully");

diff --git a/examples/basic-usage.ts b/examples/basic-usage.ts
@@ -3,12 +3,12 @@ import { biller } from "./scrawn/biller.ts";
 async function main() {
   await biller.basicUsageEventConsumer({
     userId: "c0971bcb-b901-4c3e-a191-c9a97871c39f",
-    debitAmount: 3000,
+    debit: 3000,
   });
 
   await biller.basicUsageEventConsumer({
     userId: "c0971bcb-b901-4c3e-a191-c9a97871c39f",
-    debitTag: "PREMIUM_CALL",
+    debit: biller.tag("PREMIUM_CALL"),
   });
 
   console.log("Basic usage events consumed successfully");

diff --git a/examples/middleware-usage.ts b/examples/middleware-usage.ts
@@ -8,7 +8,7 @@ app.use(
   biller.middlewareEventConsumer({
     extractor: (req) => ({
       userId: (req.headers?.["x-user-id"] as string) || "anonymous",
-      debitAmount: req.body?.cost || 1,
+      debit: req.body?.cost || 1,
     }),
     blacklist: ["/api/collect-payment", "/api/status"],
   })

diff --git a/packages/scrawn/README.md b/packages/scrawn/README.md
@@ -35,6 +35,6 @@ const biller = scrawn({
 // Track a billable event
 await biller.sdkCallEventConsumer({
   userId: "user-123",
-  debitAmount: 100,
+  debit: 100,
 });
 ```
diff --git a/packages/scrawn/src/core/ai/track.ts b/packages/scrawn/src/core/ai/track.ts
@@ -1,4 +1,4 @@
-import type { AITokenUsagePayload, DebitField } from "../types/event.js";
+import type { AITokenUsagePayload, Debit } from "../types/event.js";
 import type {
   BillableCallParams,
   LanguageModelUsage,
@@ -15,10 +15,10 @@ export function buildAIPayload<TTag extends string = string>(
   usage: LanguageModelUsage,
   overrides: BillableCallParams<TTag>,
   defaults: {
-    inputDebit: DebitField<TTag>;
-    outputDebit: DebitField<TTag>;
-    inputCacheDebit: DebitField<TTag>;
-    outputCacheDebit: DebitField<TTag>;
+    inputDebit: Debit<TTag>;
+    outputDebit: Debit<TTag>;
+    inputCacheDebit: Debit<TTag>;
+    outputCacheDebit: Debit<TTag>;
     provider?: string;
   }
 ): AITokenUsagePayload<TTag> {

diff --git a/packages/scrawn/src/core/ai/types.ts b/packages/scrawn/src/core/ai/types.ts
@@ -1,18 +1,18 @@
-import type { DebitField } from "../types/event.js";
+import type { Debit } from "../types/event.js";
 
 /**
  * Configuration for the biller.ai() wrapper.
  * Default billing settings applied automatically to all AI SDK calls.
  */
 export interface BillableAIOptions<TTag extends string = string> {
   /** Default billing for input tokens (required). */
-  inputDebit: DebitField<TTag>;
+  inputDebit: Debit<TTag>;
   /** Default billing for output tokens (required). */
-  outputDebit: DebitField<TTag>;
+  outputDebit: Debit<TTag>;
   /** Default billing for cached input tokens. Falls back to inputDebit if not set. */
-  inputCacheDebit?: DebitField<TTag>;
+  inputCacheDebit?: Debit<TTag>;
   /** Default billing for cached output tokens. Falls back to outputDebit if not set. */
-  outputCacheDebit?: DebitField<TTag>;
+  outputCacheDebit?: Debit<TTag>;
   /** Default provider override. If not set, auto-detected from the model's provider. */
   provider?: string;
 }
@@ -25,13 +25,13 @@ export interface BillableCallParams<TTag extends string = string> {
   /** The user ID to bill against. If omitted, billing is skipped. */
   userId?: string;
   /** Override input token billing for this specific call. */
-  inputDebit?: DebitField<TTag>;
+  inputDebit?: Debit<TTag>;
   /** Override output token billing for this specific call. */
-  outputDebit?: DebitField<TTag>;
+  outputDebit?: Debit<TTag>;
   /** Override cached input token billing for this specific call. */
-  inputCacheDebit?: DebitField<TTag>;
+  inputCacheDebit?: Debit<TTag>;
   /** Override cached output token billing for this specific call. */
-  outputCacheDebit?: DebitField<TTag>;
+  outputCacheDebit?: Debit<TTag>;
   /** Override provider for this specific call. */
   provider?: string;
 }

diff --git a/packages/scrawn/src/core/pricing/builders.ts b/packages/scrawn/src/core/pricing/builders.ts
@@ -23,7 +23,6 @@ import type {
   PriceExpr,
   ExprInput,
   ExprRef,
-  ScrawnExpr,
 } from "./types.js";
 import { validateExpr } from "./validate.js";
 
@@ -37,10 +36,7 @@ function toExpr<TTag extends string = string>(
   if (typeof input === "number") {
     return { kind: "amount", value: input } as const;
   }
-  if ("_expr" in (input as unknown as Record<string, unknown>)) {
-    return (input as ScrawnExpr<TTag>)._expr as PriceExpr<TTag>;
-  }
-  return input as PriceExpr<TTag>;
+  return input;
 }
 
 /**

diff --git a/packages/scrawn/src/core/pricing/index.ts b/packages/scrawn/src/core/pricing/index.ts
@@ -31,7 +31,6 @@ export type {
   InputTokensExpr,
   OutputTokensExpr,
   ExprRef,
-  ScrawnExpr,
   PriceExpr,
   ExprInput,
 } from "./types.js";

diff --git a/packages/scrawn/src/core/pricing/types.ts b/packages/scrawn/src/core/pricing/types.ts
@@ -82,28 +82,6 @@ export interface ExprRef {
   readonly name: string;
 }
 
-/**
- * A wrapped pricing expression — the only type accepted by `debitExpr` fields.
- *
- * Created exclusively via `biller.expr()`. This wrapper ensures all expressions
- * flow through a consistent entry point that provides type-safety for both
- * inline expressions and persisted expression references.
- *
- * @typeParam TTag - The tag name type flowing through the expression tree
- *
- * @example
- * ```typescript
- * // inline expression
- * const expr = biller.expr(mul(biller.tag("PREMIUM_CALL"), 3));
- *
- * // persisted expression reference
- * const expr = biller.expr("MY_EXPR");
- * ```
- */
-export interface ScrawnExpr<TTag extends string = string> {
-  readonly _expr: PriceExpr<TTag> | ExprRef;
-}
-
 /**
  * A pricing expression - can be a literal amount, a tag reference, an operation,
  * a token placeholder (inputTokens/outputTokens), or a persisted expression reference.
@@ -124,7 +102,4 @@ export type PriceExpr<TTag extends string = string> =
  *
  * @typeParam TTag - The tag name type flowing through the expression tree
  */
-export type ExprInput<TTag extends string = string> =
-  | PriceExpr<TTag>
-  | ScrawnExpr<TTag>
-  | number;
+export type ExprInput<TTag extends string = string> = PriceExpr<TTag> | number;