feat: typesafe prompts.resolve<typeof myPrompt>() with PromptIdentifier and PromptVariables inference

Author: ericallam

packages/trigger-sdk/src/v3/prompt.ts

@@ -10,8 +10,11 @@ import {
 } from "@trigger.dev/core/v3";
 import { tracer } from "./tracer.js";
 
-type PromptOptions<TVariables extends TaskSchema | undefined = undefined> = {
-  id: string;
+type PromptOptions<
+  TIdentifier extends string = string,
+  TVariables extends TaskSchema | undefined = undefined,
+> = {
+  id: TIdentifier;
   description?: string;
   model?: string;
   config?: Record<string, unknown>;
@@ -37,14 +40,30 @@ type ResolvedPrompt = {
 
 export type { PromptOptions, ResolvedPrompt };
 
-export type PromptHandle<TVariables extends TaskSchema | undefined = undefined> = {
-  id: string;
+export type PromptHandle<
+  TIdentifier extends string = string,
+  TVariables extends TaskSchema | undefined = undefined,
+> = {
+  id: TIdentifier;
   resolve(
     variables: inferSchemaIn<TVariables>,
     options?: { label?: string; version?: number }
   ): Promise<ResolvedPrompt>;
 };
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type AnyPromptHandle = PromptHandle<string, any>;
+
+/** Extract the identifier (id literal type) from a PromptHandle */
+export type PromptIdentifier<T extends AnyPromptHandle> = T extends PromptHandle<infer TId, any>
+  ? TId
+  : string;
+
+/** Extract the variables input type from a PromptHandle */
+export type PromptVariables<T extends AnyPromptHandle> = T extends PromptHandle<any, infer TVariables>
+  ? inferSchemaIn<TVariables>
+  : Record<string, unknown>;
+
 /**
  * Compile a Mustache-style template by substituting `{{variable}}` placeholders.
  */
@@ -101,7 +120,7 @@ function makeToAISDKTelemetry(
 }
 
 function resolveLocally(
-  options: PromptOptions<any>,
+  options: PromptOptions<any, any>,
   variables: Record<string, unknown>
 ): ResolvedPrompt {
   const inputJson = Object.keys(variables).length > 0 ? JSON.stringify(variables) : undefined;
@@ -118,9 +137,12 @@ function resolveLocally(
   };
 }
 
-export function definePrompt<TVariables extends TaskSchema | undefined = undefined>(
-  options: PromptOptions<TVariables>
-): PromptHandle<TVariables> {
+export function definePrompt<
+  TIdentifier extends string,
+  TVariables extends TaskSchema | undefined = undefined,
+>(
+  options: PromptOptions<TIdentifier, TVariables>
+): PromptHandle<TIdentifier, TVariables> {
   const parseVariables = options.variables
     ? getSchemaParseFn(options.variables)
     : undefined;

packages/trigger-sdk/src/v3/promptManagement.ts

@@ -10,7 +10,7 @@ import {
   type PromptOverrideCreatedResponseBody,
   type UpdatePromptOverrideRequestBody,
 } from "@trigger.dev/core/v3";
-import type { ResolvedPrompt } from "./prompt.js";
+import type { AnyPromptHandle, PromptIdentifier, PromptVariables, ResolvedPrompt } from "./prompt.js";
 import { tracer } from "./tracer.js";
 
 function promptSpanOptions(name: string, slug: string) {
@@ -59,9 +59,9 @@ function makeToAISDKTelemetry(
  * compiled text. Works both inside and outside of a task context — requires
  * an API client to be configured (via `configure()` or task runtime).
  */
-export async function resolvePrompt(
-  slug: string,
-  variables?: Record<string, unknown>,
+export async function resolvePrompt<TPromptHandle extends AnyPromptHandle = AnyPromptHandle>(
+  slug: PromptIdentifier<TPromptHandle>,
+  variables?: PromptVariables<TPromptHandle>,
   options?: { label?: string; version?: number; requestOptions?: ApiRequestOptions }
 ): Promise<ResolvedPrompt> {
   const apiClient = apiClientManager.clientOrThrow();

packages/trigger-sdk/src/v3/prompts.ts

@@ -1,5 +1,12 @@
 export { definePrompt as define } from "./prompt.js";
-export type { PromptHandle, PromptOptions, ResolvedPrompt } from "./prompt.js";
+export type {
+  AnyPromptHandle,
+  PromptHandle,
+  PromptIdentifier,
+  PromptOptions,
+  PromptVariables,
+  ResolvedPrompt,
+} from "./prompt.js";
 
 export {
   resolvePrompt as resolve,

references/hello-world/src/trigger/prompts.ts

@@ -302,8 +302,12 @@ export const testPromptManagement = task({
     const versions = await prompts.versions(slug);
     logger.info("Listed versions", { slug, count: versions.data.length });
 
-    // Resolve the prompt (standalone, not via PromptHandle)
-    const resolved = await prompts.resolve(slug, { customerName: "SDK Test", plan: "Enterprise", issue: "Testing management API" });
+    // Resolve the prompt (standalone, typesafe via generic)
+    const resolved = await prompts.resolve<typeof supportPrompt>("customer-support", {
+      customerName: "SDK Test",
+      plan: "Enterprise",
+      issue: "Testing management API",
+    });
     logger.info("Resolved prompt standalone", { version: resolved.version, textLength: resolved.text.length });
 
     // Create an override
@@ -315,7 +319,11 @@ export const testPromptManagement = task({
     logger.info("Created override", { version: override.version });
 
     // Resolve again — should get the override
-    const resolvedOverride = await prompts.resolve(slug, { customerName: "SDK Test", plan: "Enterprise", issue: "Testing override" });
+    const resolvedOverride = await prompts.resolve<typeof supportPrompt>("customer-support", {
+      customerName: "SDK Test",
+      plan: "Enterprise",
+      issue: "Testing override",
+    });
     logger.info("Resolved with override", { version: resolvedOverride.version, text: resolvedOverride.text });
 
     // Update the override