fix: docs corrections and dead code cleanup (#172)

1. README: Node.js requirement 22.0.0 → 20.0.0 (matches package.json
   engines field and CI matrix which tests both 20.x and 22.x)

2. getRequestHeaders JSDoc: fix wrong method call in @example
   - Was calling getServiceMetadata twice (second should be getRequestHeaders)
   - Remove non-existent serviceName parameter
   - Fix message role from "system" to "user"
   - Fix headers placement in OpenAI SDK call

3. response.ts: remove duplicate chatID null check (dead code)
   - Line 38 already returns null if !chatID
   - Second check at line 54 was unreachable
   - Replace console.warn with existing logger.warn (3 occurrences)

4. request.ts: remove commented-out import

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: dorukardahan

README.md

@@ -12,7 +12,7 @@ Access decentralized AI computing through the 0G Compute Network - a GPU marketp
 
 ## Requirements
 
-- Node.js >= 22.0.0
+- Node.js >= 20.0.0
 - A wallet with 0G tokens
 
 ## Installation

src.ts/sdk/inference/broker/broker.ts

@@ -304,14 +304,12 @@ export class InferenceBroker extends ReadOnlyInferenceBroker {
      *
      * @example
      *
-     * const { endpoint, model } = await broker.getServiceMetadata(
+     * const { endpoint, model } = await broker.inference.getServiceMetadata(
      *   providerAddress,
-     *   serviceName,
      * );
      *
-     * const headers = await broker.getServiceMetadata(
+     * const headers = await broker.inference.getRequestHeaders(
      *   providerAddress,
-     *   serviceName,
      *   content,
      * );
      *
@@ -322,12 +320,10 @@ export class InferenceBroker extends ReadOnlyInferenceBroker {
      *
      * const completion = await openai.chat.completions.create(
      *   {
-     *     messages: [{ role: "system", content }],
+     *     messages: [{ role: "user", content }],
      *     model,
      *   },
-     *   headers: {
-     *     ...headers,
-     *   },
+     *   { headers: { ...headers } },
      * );
      *
      * @throws An error if errors occur during the processing of the request.

src.ts/sdk/inference/broker/request.ts

@@ -4,7 +4,7 @@ import type { InferenceServingContract } from '../contract'
 import type { LedgerBroker } from '../../ledger'
 import { Automata } from '../../common/automata'
 import { throwFormattedError } from '../../common/utils'
-// import { Verifier } from './verifier'
+
 
 /**
  * ServingRequestHeaders contains headers related to request.

src.ts/sdk/inference/broker/response.ts

@@ -42,21 +42,17 @@ export class ResponseProcessor extends ZGServingUserBrokerBase {
 
             const svc = await extractor.getSvcInfo()
             if (!isVerifiability(svc.verifiability)) {
-                console.warn('this service is not verifiable')
+                logger.warn('this service is not verifiable')
                 return false
             }
 
             if (!svc.teeSignerAcknowledged) {
-                console.warn('TEE Signer is not acknowledged')
+                logger.warn('TEE Signer is not acknowledged')
                 return false
             }
 
-            if (!chatID) {
-                throw new Error('Chat ID does not exist')
-            }
-
             if (!svc.additionalInfo) {
-                console.warn('Service additionalInfo does not exist')
+                logger.warn('Service additionalInfo does not exist')
                 return false
             }