hecigo Developer Resources

This page is the index; each entry below is a stable, predictable URL you can bookmark or hard-code.

hecigo is an AI-native software lab: we build products and the connective layer that lets systems, data and AI agents work together. Developers is one of three pillars, next to Products and Solutions, and it is the one that is open source.

If you are an AI agent, start with hecigo.com/llms.txt, which names what this site is for and when to reach for us.

Open-source n8n nodes by hecigo

hecigo maintains two n8n community nodes on npm. Both are MIT licensed, both are used outside our own projects, and both take issues.

n8n-nodes-zalo-platform

An n8n community node for the Zalo Bot Platform: send messages, photos and stickers, and manage webhooks. Nine operations. Zalo is the dominant messaging platform in Vietnam, and this node is what we use to reach it from an n8n workflow.

npm: npmjs.com/package/n8n-nodes-zalo-platform
Source and README: github.com/hecigo/n8n-nodes-zalo-platform
Install in n8n: Settings → Community Nodes → Install → n8n-nodes-zalo-platform
Install from a shell: npm install n8n-nodes-zalo-platform
Licence: MIT
What breaks in production, written up honestly: Running a Zalo bot on n8n: what breaks between test mode and production

n8n-nodes-firecrawl-v2

An n8n community node covering the Firecrawl v2 API (scrape, crawl, map, search, extract, and the batch operations) against both Firecrawl Cloud and a self-hosted instance. Ten operations, six of which return web content and are not interchangeable.

npm: npmjs.com/package/n8n-nodes-firecrawl-v2
Source and README: github.com/hecigo/n8n-nodes-firecrawl-v2
Install in n8n: Settings → Community Nodes → Install → n8n-nodes-firecrawl-v2
Install from a shell: npm install n8n-nodes-firecrawl-v2
Licence: MIT
Which operation to reach for: Firecrawl on n8n: picking the right operation, and what async does to your workflow

All hecigo source lives under the GitHub organisation github.com/hecigo. Issues and pull requests on either node are the fastest route to a case being covered.

Ads Insights over MCP

Ads Insights is a hosted, read-only MCP server for Meta Ads, Google Ads, TikTok Ads, Google Analytics 4 and Google Search Console. The assistant calls an Ads Insights tool, the tool reads each source's API directly, and the numbers come back in one shape.

MCP endpoint: https://ads.hecigo.com/mcp (streamable HTTP)
Server card: ads.hecigo.com/.well-known/mcp/server-card.json
Sign-in: OAuth. The advertiser grants access on Meta's, Google's or TikTok's own consent screen and can revoke it there at any time.
Tools: twelve, and every one declares readOnlyHint. Nothing in it creates, pauses, edits or funds an ad.

Paste the endpoint into the connector settings of Claude, ChatGPT, Cursor, VS Code or any other MCP client. How authorization, revocation and customer data work is on the product page; the sign-in and example prompts are at ads.hecigo.com.

Machine-readable endpoints on hecigo.com

Endpoint	Format	What it is
/llms.txt	Markdown, llmstxt.org	Site summary, when to use hecigo, and a link index
/llms-full.txt	Markdown	Every public page and post concatenated, for a single fetch
/agent-instructions.md	Markdown	How an agent should call, cite, and hand off to hecigo
/openapi.json	OpenAPI 3.1	Every endpoint on this page, described formally
/sitemap.xml	XML	Every indexable URL, with last-modified dates
/robots.txt	Text	Crawl rules; no AI crawler is blocked
/blog-index.json	JSON	Blog metadata: slug, title, description, date, tags, language

Everything in the table is public, unauthenticated, CORS-open, and free to fetch. There is no rate limit beyond the CDN's own abuse protection. Please send a user agent that identifies your client.

The OpenAPI document

/openapi.json describes this surface in OpenAPI 3.1: every path above, the Accept negotiation on canonical page URLs, the schema of blog-index.json, and the shape of the error bodies. It is generated from the same manifest the negotiation runs on, so a retired post cannot linger in it.

Read what it is carefully, because the word "API" invites the wrong assumption: it documents a read-only website surface on hecigo.com, not a hosted hecigo product. Every operation is a GET. There is no API key, no OAuth flow and no write path behind it. The one hosted product, Ads Insights, lives on its own domain, speaks MCP rather than REST, and is described by its own server card.

The knowledge base

The site is also published as data, split into chunks an agent or a retrieval index can load without scraping HTML:

/knowledge/index.jsonl: one JSON object per line, one line per H2 section of every page, post and product, in both languages. Each object carries id, url, locale, type, title, headingPath, text, entities and updated.
/knowledge/entities.json: the things those chunks talk about, the organisation and each product, with the ids the entities field points at, such as org:hecigo and product:ads-insights.

Ids are stable. They are built from the type, slug, locale and section anchor, never from the text, so a corrected sentence updates a chunk in place instead of creating a duplicate. A section longer than the chunk limit is split by paragraph and gets a suffix: ~2, ~3. Where a page renders its headings as anchors, url points at that section.

Markdown content negotiation

Every public page on hecigo.com is available as Markdown at the same URL. Send Accept: text/markdown and you get clean prose instead of a page of layout markup, per the convention documented at acceptmarkdown.com:

curl -s -H "Accept: text/markdown" https://hecigo.com/
curl -s -H "Accept: text/markdown" https://hecigo.com/blog/n8n-zalo-bot-node-what-breaks-in-production/

Responses carry Content-Type: text/markdown; charset=utf-8 and Vary: Accept, Accept-Encoding. Q-values are honoured, so a browser's Accept: text/html,...,*/*;q=0.8 still gets HTML.

Every page also ships a .md sibling if you would rather address it directly, advertised on the HTML response as Link: </index.md>; rel="alternate"; type="text/markdown". Vietnamese is the default language: Vietnamese pages are /<name>.md and the homepage is /index.md. English pages live under /en/: /en/<name>.md, with the English homepage at /en.md.

curl -s https://hecigo.com/index.md
curl -s https://hecigo.com/developers.md
curl -s https://hecigo.com/en/developers.md

A request for a path that does not exist returns a real HTTP 404, and a request whose Accept header we genuinely cannot satisfy returns 406 Not Acceptable rather than silently handing back the wrong format. Both answer in a format you can parse; see Errors below.

Errors

Errors on this site default to JSON, shaped per RFC 9457. You do not have to ask for it:

curl -s https://hecigo.com/no-such-page/
curl -s https://hecigo.com/blog/no-such-post.md

{
  "type": "https://hecigo.com/developers/#http-404",
  "title": "Not Found",
  "status": 404,
  "detail": "There is no page at /no-such-page/ on hecigo.com.",
  "instance": "/no-such-page/",
  "code": "not_found",
  "resolution": "Fetch https://hecigo.com/llms.txt for the link index or https://hecigo.com/sitemap.xml for every URL. ...",
  "documentation_url": "https://hecigo.com/developers/#errors",
  "links": { "agentIndex": "https://hecigo.com/llms.txt", "...": "..." }
}

Branch on code, not on the prose in title or detail. There are two values: not_found and representation_not_available.

Why JSON is the default

Because of what the wire actually tells us. A browser names text/html outright in its Accept header, so a person who mistypes a URL still gets the rendered 404 page. curl, fetch, and every HTTP client library send */* or no Accept header at all, and the catch-all wildcard is not a claim to read HTML. That is the whole distinction:

What you send	What a 404 gives you
Nothing, or `/`	JSON problem document
`Accept: application/json`	JSON problem document
`Accept: text/markdown`	The Markdown recovery map
`Accept: text/html`, which is what a browser sends	The rendered 404 page

This used to be the other way round: JSON arrived only if you named it, and everything else got prose. An agent with a default header had no way to guess which header would have worked.

The status code is chosen on evidence

HTTP 404

There is no such path. The body names the path it is answering about, so an agent fetching several dead URLs can tell the responses apart, and resolution points at /llms.txt and /sitemap.xml.

HTTP 406

The path exists, but no representation matches your Accept header. The available member names the two formats it does have. Calling this a 404 would say the page is not there; calling a genuine 404 a 406 would say a dead path is real and worth retrying in another format. The 406 body is JSON in every case, including when you asked for something we have never heard of.

Every error carries links in its headers

Including the HTML 404 page, which is how a client that cannot parse the page still finds its way to this document:

Link: <https://hecigo.com/openapi.json>; rel="service-desc"; type="application/vnd.oai.openapi+json",
      <https://hecigo.com/llms.txt>; rel="service-doc"; type="text/plain",
      <https://hecigo.com/developers/#errors>; rel="help"; type="text/html"

Error responses carry Vary: Accept, Accept-Encoding and Cache-Control: no-store, since the format of the body is chosen from a request header.

One limit worth knowing: paths that carry a non-document extension, such as /og-image.png, are not routed through negotiation at all, so their errors are the CDN's own. The document extensions .md, .txt, .json and .xml are.

What hecigo does not publish

Stated plainly so nobody wastes an afternoon looking:

No product API on this domain. /openapi.json describes this website's read-only surface, and nothing more. Integration engagements in the Solutions pillar run inside client infrastructure, so there is nothing multi-tenant to call there either. The one hosted product, Ads Insights, lives on ads.hecigo.com and speaks MCP, not REST.
No write endpoints on this domain. Every operation documented here is a GET.
No webhooks you can subscribe to. The only webhook on this domain is the enquiry-form intake, which is ours, not yours.

The public, usable surface is the two n8n nodes, the endpoints and knowledge base above, and the Ads Insights MCP endpoint. When there is more, this page is where it appears.

Getting in touch about the code

Bugs and feature requests on the nodes: open an issue on the relevant GitHub repository, with the payload that broke it.
Everything else: hi@hecigo.com, or the form at hecigo.com/en/contact.

Back to home /en/developers.md