Typed connectors — Cliodot Documentation

Runtime boundary: Typed connectors improve TypeScript safety. They do not validate runtime values unless you add validation steps.

This guide shows how to build and use typed connectors with real examples.

Why typed connectors are needed#

Without typed connectors, connector calls are usually string + any:

Action names can be misspelled and fail only at runtime.
Request payload shape (body, params, pathParams, headers) is not validated by TypeScript.
Response shape is unknown, so downstream workflow code (or ctx.input) has weak IntelliSense.
Teams duplicate implicit API contracts across files and docs.

Typed connectors solve this by making the connector contract explicit in one place and reusable everywhere.

What a typed connector gives you#

When you call defineTypedConnector(...), you get:

A stable connector identifier (id).
Action keys with autocomplete (actions + typed key overloads).
A schema map (__schemas) used by helper types.
Strong typing across:
@Connector(...) decorator config
s.connector(...) builder config
flosync.runConnector(...) options
type extraction helpers like ConnectorResponse<...>

How it works (compile-time vs runtime)#

Typed connectors are primarily a TypeScript feature:

Compile-time
TypeScript checks that the action key exists.
TypeScript checks config shape for body, params, pathParams, headers, vars.
TypeScript infers response type helpers.
Runtime
The runner still executes regular connector actions by connectorId + action.
Schemas are not runtime validators by default.
Templates ("{{ ... }}") still work and are intentionally allowed in typed fields.

Think of typed connectors as a contract layer over the existing execution engine.

Schema field semantics#

body: request payload body
params: query string parameters
pathParams: path replacements (for :id, :reference, etc.)
headers: request headers
vars: step-scoped values merged into workflow vars before execution
response: expected result shape for typing and editor support

Recommended usage pattern#

Define connector schema once near the connector.
Use typed action key style in workflows: @Connector(Paystack, "initializeTransaction", ...).
Use satisfies ConnectorTypedRequestConfig<...> for request config objects.
Use ConnectorResponse<...> (or related helpers) when annotating step output contexts.
Keep schema close to real provider docs and update it when provider contracts change.

1) Define a typed connector#

import { defineTypedConnector } from "@cliodot/flosync";

export const Paystack = defineTypedConnector(
 "paystack",
 {
   initializeTransaction: "initializeTransaction",
   verifyTransaction: "verifyTransaction",
 },
 {
   initializeTransaction: {
     body: {} as {
       email: string;
       amount: number;
       reference?: string;
       callback_url?: string;
     },
     headers: {} as {
       "Idempotency-Key"?: string;
     },
     vars: {} as {
       traceId?: string;
     },
     response: {} as {
       status: boolean;
       message: string;
       data: {
         authorization_url: string;
         access_code: string;
         reference: string;
       };
     },
   },
   verifyTransaction: {
     pathParams: {} as { reference: string },
     response: {} as {
       status: boolean;
       message: string;
       data: {
         id: number;
         status: string;
         reference: string;
         amount: number;
         currency: string;
         paid_at: string | null;
       };
     },
   },
 }
);

2) Extract strongly typed request/response helpers#

import type {
 ConnectorBody,
 ConnectorHeaders,
 ConnectorPathParams,
 ConnectorResponse,
 ConnectorTypedRequestConfig,
 ConnectorVars,
} from "@cliodot/flosync";

type InitBody = ConnectorBody<typeof Paystack, "initializeTransaction">;
type InitHeaders = ConnectorHeaders<typeof Paystack, "initializeTransaction">;
type InitVars = ConnectorVars<typeof Paystack, "initializeTransaction">;
type VerifyPath = ConnectorPathParams<typeof Paystack, "verifyTransaction">;
type InitResponse = ConnectorResponse<typeof Paystack, "initializeTransaction">;

type InitConfig = ConnectorTypedRequestConfig<typeof Paystack, "initializeTransaction">;

3) Use it in decorator workflows#

import {
 Workflow,
 Http,
 Connector,
 Responder,
 Validator,
 variable as v,
} from "@cliodot/flosync";
import type {
 ConnectorTypedRequestConfig,
 ConnectorResponse,
} from "@cliodot/flosync";
import { Paystack } from "../connectors/paystack.connector";

type InitializePaymentRequest = ConnectorTypedRequestConfig<
 typeof Paystack,
 "initializeTransaction"
>;
type InitializePaymentResponse = ConnectorResponse<
 typeof Paystack,
 "initializeTransaction"
>;

@Workflow("payment-initialize", "Initialize Payment")
@Http("POST", "/payment/initialize")
export class PaymentInitializeWorkflow {
 @Validator(
   [
     {
       fields: [v.body("email")],
       validators: [{ name: "required" }, { name: "is_email" }],
     },
     {
       fields: [v.body("amount")],
       validators: [{ name: "required" }],
     },
   ],
   { order: 0, then: "generateReference", else: "invalid" }
 )
 validate() {}

 @Responder(
   "json",
   {
     statusCode: 400,
     body: {
       ok: false,
       message: "Validation failed",
       errors: v.stepResult("validate", "errors"),
     },
   },
   { order: 1 }
 )
 invalid() {}

 @Connector("utility.random", "random_uuid", {}, { order: 2 })
 generateReference() {}

 @Connector(
   Paystack,
   "initializeTransaction",
   {
     body: {
       email: v.body("email"),
       amount: v.body("amount"),
       reference: v.stepResult("generateReference", "value"),
     },
     headers: {
       "Idempotency-Key": v.stepResult("generateReference", "value"),
     },
     vars: {
       traceId: v.stepResult("generateReference", "value"),
     },
   } satisfies InitializePaymentRequest,
   { order: 3, then: "respond", else: "initError" }
 )
 initialize() {}

 @Responder(
   "json",
   {
     body: {
       message: "Payment initialized successfully",
       data: v.stepResult("initialize") as unknown as InitializePaymentResponse,
     },
   },
   { order: 4 }
 )
 respond() {}

 @Responder(
   "json",
   {
     statusCode: 400,
     body: {
       message: "Payment initialization failed",
       data: v.stepResult("initialize"),
     },
   },
   { order: 5 }
 )
 initError() {}
}

4) Use it in builder-style workflows#

import { flosync, variable as v } from "@cliodot/flosync";
import { Paystack } from "../connectors/paystack.connector";

const workflow = flosync
 .workflow("payment-verify", "Verify Payment")
 .http("GET", "/payment/verify/:reference")
 .step("verify", (s) =>
   s.connector(Paystack, "verifyTransaction", {
     pathParams: { reference: v.pathParam("reference") },
   })
 )
 .step("respond", (s) =>
   s.responder("json", {
     body: {
       message: "Payment verified successfully",
       data: v.stepResult("verify"),
     },
   })
 )
 .build();

5) Use it in direct connector execution#

import { flosync } from "@cliodot/flosync";
import { Paystack } from "../connectors/paystack.connector";

const result = await flosync.runConnector(
 Paystack,
 "verifyTransaction",
 {
   pathParams: { reference: "ref_123" },
 },
 { remote: true }
);

Notes#

Typed connectors support both usage styles:
Typed style: @Connector(Paystack, "initializeTransaction", ...)
Classic style: @Connector(Paystack.id, Paystack.actions.initializeTransaction, ...)
Template expressions are supported in typed request fields (body, params, pathParams, headers, vars).
Use satisfies ConnectorTypedRequestConfig<...> to enforce shape while keeping expression values.

Common pitfalls and fixes#

Using action value instead of action key
Use "initializeTransaction" (the key), not a random string.
Expecting schema to validate runtime payloads
Schema gives TypeScript safety; add validator steps if you need runtime validation.
Forgetting optional fields in provider responses
Mark uncertain fields as optional in response to avoid brittle assumptions.
Mixing classic and typed style inconsistently
Prefer typed style for new workflows; keep classic only where migration is pending.

Migration strategy for existing workflows#

For each connector/action pair:

Introduce a typed connector definition with current contract.
Replace @Connector("id", "action", config) with @Connector(TypedDef, "actionKey", config).
Add satisfies ConnectorTypedRequestConfig<...> to the config object.
Add response helper types only where they improve readability (avoid over-annotating everything).
Run typecheck and fix mismatches surfaced by TypeScript.