Lesson 201: Triple-Channel HTML5 build_label and channel_label_match Receipt (2026)

Direct answer: When itch.io, GX.games, and Steam HTML5 builds all ship from one repo, channel_label_match on BUILD_RECEIPT must compare normalized labels from a single root VERSION file—not three upload dashboards that each invent their own string. This lesson ships triple_channel_label_receipt_v1.json and an itch_public row in your playtest scope map.

Lesson hero for triple-channel HTML5 channel_label_match receipt

Why this matters now (July 2026 triple HTML5)

July 2026 micro-studios run three public HTML5 surfaces in parallel:

itch for jam links and fest embeds (subdomain WASM smoke)
GX.games for discovery uploads
Steam for wishlist + playtest routing (playtest isolation)

Pairwise CI still passes Steam + GX while channel_label_match flips false the moment itch joins—because itch logs numeric game IDs or title-case slugs, not your fest build_label. The triple-channel help fix documents symptoms; this lesson is the course milestone that wires the assembler into your live-ops gate chain after Lesson 200 concat_ok.

Beginner path (45-minute proof)

Step	Action	Success check
1	Copy repo-root `VERSION` to clipboard	One line, no trailing spaces
2	Upload GX + Steam from same `git_sha`	Upload logs show identical commit
3	Map itch label from `VERSION` (not game ID)	itch dashboard matches string
4	Add `itch_public` to `playtest_scope_map_v1.json`	JSON validates
5	Run triple-channel compare script	All three `normalized_match: true`
6	Write `triple_channel_label_receipt_v1.json`	`channel_label_match: true`
7	Patch BUILD_RECEIPT row	`channel_label_match` true in CI

Time: ~45 minutes first pass; full lesson 72 minutes with SQL gate + facilitator README.

Developer path (gates H1–H6)

Gate	Check	Fail when
H1	Single `VERSION` source	Multiple version files diverge
H2	`git_sha` identical on three upload logs	Hotfix on one channel only
H3	itch label derived from `VERSION`	Raw itch slug in receipt
H4	`playtest_scope_map` includes `itch_public`	Missing scope row
H5	Normalized compare (case-fold)	Strict string mismatch on case only
H6	BUILD_RECEIPT `channel_label_match`	Any H1–H5 red

`playtest_scope_map_v1.json` (itch row)

{
  "surfaces": [
    {"id": "fest_public", "store": "steam", "build_label_source": "VERSION"},
    {"id": "gx_public", "store": "gx", "build_label_source": "VERSION"},
    {"id": "itch_public", "store": "itch", "build_label_source": "VERSION", "url_pattern": "*.itch.io"}
  ]
}

`triple_channel_label_receipt_v1.json`

{
  "schema": "triple_channel_label_receipt_v1",
  "version_source": "VERSION",
  "git_sha": "abc1234",
  "channels": [
    {"surface": "steam", "logged_label": "fest-demo-2026-05-24-rc2", "normalized_match": true},
    {"surface": "gx", "logged_label": "fest-demo-2026-05-24-rc2", "normalized_match": true},
    {"surface": "itch", "logged_label": "fest-demo-2026-05-24-rc2", "normalized_match": true}
  ],
  "channel_label_match": true,
  "itch_public_scope_ok": true
}

Pin under release-evidence/html5/TRIPLE_CHANNEL_LABEL_RECEIPT.json.

`itch_public` scope map notes

itch_public is the receipt surface id—do not reuse gx_public for itch URLs.
Custom-domain itch hosts belong in Construct CORS playbook; this lesson assumes subdomain *.itch.io for label parity with upload logs.

Compare script sketch

from pathlib import Path

VERSION = Path("VERSION").read_text().strip()
channels = {
    "steam": Path("logs/steam_upload.log").read_text(),
    "gx": Path("logs/gx_upload.log").read_text(),
    "itch": Path("logs/itch_upload.log").read_text(),
}

def extract_label(log: str) -> str:
    for line in log.splitlines():
        if "build_label=" in line:
            return line.split("=", 1)[1].strip()
    raise ValueError("build_label missing")

rows = []
for surface, log in channels.items():
    label = extract_label(log)
    rows.append({
        "surface": surface,
        "logged_label": label,
        "normalized_match": label.casefold() == VERSION.casefold(),
    })

assert all(r["normalized_match"] for r in rows), rows

Publish gate

ALTER TABLE release_publish_gate ADD COLUMN IF NOT EXISTS
  triple_channel_label_blocked BOOLEAN NOT NULL DEFAULT false;

CI job verify_triple_channel_labels_v1 sets the flag false only when receipt JSON passes and itch MIME help post_upload_mime_ok is true for the itch lane.

Prerequisites

Lesson 200 — honest playtest timelines (concat_ok)
GX multi-channel tools resource
itch WASM MIME cross-check list

Common mistakes

Logging itch game ID instead of fest build_label.
Uploading itch from a fork with different VERSION text.
Omitting itch_public in scope map while itch URL is in facilitator README.
Passing Thursday row review without an itch column.

Troubleshooting

Symptom	Cause	Fix
GX+Steam pass, itch fails	itch slug casing	Normalize compare; fix itch dashboard field
`channel_label_match` false, logs look identical	Hidden whitespace in `VERSION`	`trim()` + visual diff
itch MIME green, label red	Different issues	Run MIME receipt + label receipt separately

Mini exercise (50 minutes)

Seed three upload logs with one VERSION.
Break H3 on purpose (itch uses wrong slug); confirm gate fails.
Fix itch mapping; regenerate receipt.
Link receipt in facilitator contract (pairs blog #11 when published).
Cross-link from triple-channel help Related section.

Continuity

Previous: Lesson 200 — concat_ok
Next: Lesson 202 — Weblate string table smoke
Guides (planned): GameMaker GX upload preflight (Guide queue #8)

FAQ

Does this replace the help article?
No—the help article is the fix; this lesson is the milestone wiring gates into your RPG live-ops course arc.

Custom itch domain?
Label receipts still must match VERSION; hosting proof is CORS playbook + MIME help.

Only two channels?
Set channel_label_match true only when all declared surfaces in scope map pass—do not declare itch until ready.

Three HTML5 storefronts, one VERSION spine—or your BUILD_RECEIPT will keep failing the week you need it green.