substack

Original：🇺🇸 English

Translated

1 scripts

Read and publish on Substack (substack.com) with the user's own login cookies (BYOC) — show who they are and their primary publication, list their published posts with stats, and publish a new post / newsletter. Use when the user mentions Substack, "my Substack", their newsletter, or publishing a post to Substack.

12installs

Sourceacedatacloud/skills

Added on2026-07-04

NPX Install

npx skill4agent add acedatacloud/skills substack

SKILL.md Content

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substack — read & publish on Substack via your own cookies

Drives the user's real Substack account through the same internal web API the site uses (Substack has no official public write API), authenticated by the login cookie they captured with the ACE extension. No browser, no third-party deps — just

urllib

. The publish flow mirrors the community

python-substack

library: create draft → prepublish → publish.

The connector injects the cookie jar as an env var:

```
SUBSTACK_COOKIES
```
— a JSON array of cookies (
```
substack.sid
```
,
```
substack.lli
```
, …). Secret — never echo or print it. Substack authenticates writes with the session cookie alone (no CSRF token header needed).

CLI

The skill ships

scripts/substack.py

— self-contained, stdlib only.

sh

SUB=$SKILL_DIR/scripts/substack.py
python3 $SUB whoami                       # who is logged in + primary publication
python3 $SUB articles --limit 20          # my published posts + stats

Verify the connection first

sh

python3 $SUB whoami
# → {"user_id": ..., "name": "...", "handle": "...", "publication": "...", "publication_url": "https://<sub>.substack.com"}

On an auth error the cookie is expired — have the user reconnect at https://auth.acedata.cloud/user/connections. Do not loop-retry.

Publishing — GATED (dry-run unless trailing

--confirm

)

publish

writes to the user's real account. Content is Markdown, converted to Substack's ProseMirror blocks:

..

######

→heading,

```

→code block,

→blockquote,

/

1.

→lists,

---

→horizontal rule, everything else →paragraphs. Inline bold, italic,

code

, ~~strike~~, and

[links](url)

render as real Substack formatting; bare

https://…

URLs are auto-linked.

Without a trailing

--confirm

it dry-runs.

--confirm

is honored only as the last argument. Always show the dry-run, get an explicit "yes", then re-run.

sh

# dry-run (shows the plan, writes nothing)
python3 $SUB publish --title "Title" --content-file post.md

# private draft (visible only in the user's dashboard)
python3 $SUB publish --title "Title" --content-file post.md --draft-only --confirm

# go LIVE on the web (does NOT email subscribers)
python3 $SUB publish --title "Title" --content-file post.md --confirm

# go LIVE and email subscribers (use only when the user explicitly asks)
python3 $SUB publish --title "Title" --content-file post.md --send-email --confirm

```
--draft-only
```
stops at a draft — default to this unless the user asked to go live. Returns an
```
edit_url
```
to review in the Substack editor.
Publishing does NOT email subscribers unless
```
--send-email
```
is passed. Emailing a newsletter is irreversible and hits every subscriber's inbox — never add
```
--send-email
```
without an explicit request.
```
--subtitle
```
sets the post subtitle;
```
--audience
```
is one of
```
everyone
```
(default, free/public),
```
only_paid
```
,
```
founding
```
,
```
only_free
```
.

Gotchas

This is the user's real Substack account. Confirm before any publish, and keep
```
--draft-only
```
as the safe default.
--send-email
blasts the whole subscriber list and cannot be undone — opt in only on explicit request.
Substack sits behind Cloudflare; an occasional 403/429 on a read is transient — the CLI auto-retries reads once. A persistent 401/403 means the cookie is genuinely expired (reconnect); the CLI never retries a write.
Never print
SUBSTACK_COOKIES
— it is full account access.
ToS: acts only on the user's own account with their own captured cookie.

Record the output

After you successfully publish and obtain the live result URL, call the built-in

publish_artifact

tool ONCE so the user can track this deliverable in My Outputs:

publish_artifact(kind="article", channel="substack", title="<title>", url="<the REAL returned URL>", status="delivered")

Use the real returned URL — never fabricate one. Call it once per published item, only after delivery is confirmed; skip it (or use

status="failed"

) if publishing failed. See

_shared/artifacts.md

.

substack

NPX Install

Tags

SKILL.md Content

substack — read & publish on Substack via your own cookies

CLI

Verify the connection first

Publishing — GATED (dry-run unless trailing
`--confirm`
)

Gotchas

Record the output

substack

NPX Install

Tags

SKILL.md Content

substack — read & publish on Substack via your own cookies

CLI

Verify the connection first

Publishing — GATED (dry-run unless trailing --confirm)

Gotchas

Record the output

Publishing — GATED (dry-run unless trailing
`--confirm`
)