HTTP framework (lib/core)

This repo separates domain (lib/marketplace/) from a small HTTP framework** in lib/core/. Use this skill when changing transport behavior.

contentstackHTTPClient.js

• Builds an axios instance with baseURL from endpoint or protocol://hostname:port + basePath.
• Defaults: timeout 30000, retryOnError true, retryCondition retries 429 (overridable).
• Headers: Maps apiKey / accessToken from config if present.
• Params: Custom paramsSerializer using Qs; nests JSON query with encodeURIComponent.
• Concurrency: Attaches ConcurrencyQueue to the instance.
• Logging: logHandler default from messageHandler.js (httpLogHandler).

concurrency-queue.js

• Limits parallel in-flight requests (maxRequests from client params). Changes here affect all API modules sharing the same HTTP instance.

messageHandler.js

• Central place for HTTP log/telemetry hooks. Keep implementations safe for browsers and Node bundles.

When to edit

• Retry/backoff policy, timeout, or serializer → prefer extending existing options on client() rather than one-off axios calls in marketplace modules.
• New global header behavior → contentstack.js + potentially contentstackHTTPClient.js for low-level concerns.

Testing

• test/unit/ContentstackHTTPClient-test.js and concurrency-Queue-test.js should cover behavioral changes; use mocks rather than live HTTP when possible.