Substack — Printing Press CLI

Prerequisites: Install the CLI

This skill drives the

substack-pp-cli

binary. You must verify the CLI is installed before invoking any command from this skill. If it is missing, install it first:

Install via the Printing Press installer:

bash

npx -y @mvanhorn/printing-press install substack --cli-only

Verify:
```
substack-pp-cli --version
```
Ensure
```
$GOPATH/bin
```
(or
```
$HOME/go/bin
```
) is on
```
$PATH
```
.

If the

npx

install fails (no Node, offline, etc.), fall back to a direct Go install (requires Go 1.26.3 or newer):

bash

go install github.com/mvanhorn/printing-press-library/library/media-and-entertainment/substack/cmd/substack-pp-cli@latest

--version

reports "command not found" after install, the install step did not put the binary on

$PATH

. Do not proceed with skill commands until verification succeeds.

Substack has no public API and the closed-source tools that work around it (WriteStack, StackSweller) stop at Notes scheduling and a heatmap. This CLI absorbs every endpoint the community has reverse-engineered across 8 wrappers, then transcends with local-SQLite analytics: per-Note subscriber attribution (

growth attribution

), engagement reciprocity tracking (

engage reciprocity

), and a goal-aware best-time recommender (

growth best-time

). Every command is MCP-callable so an agent can drive the full publish → engage → measure → swap loop.

When to Use This CLI

Reach for this CLI when an agent needs to operate a Substack publication end-to-end: posting Notes on a cadence, drafting and publishing long-form, engaging with niche writers, finding swap partners, and measuring which content actually drove subs. It is the right pick over WriteStack/StackSweller when you need agent-native plumbing (--json, --select, --dry-run, typed exit codes), offline-first analytics (every join runs locally over SQLite), or coverage of the writer surface those tools don't expose.

Unique Capabilities

These capabilities aren't available in any other tool for this API.

Local state that compounds

growth attribution
— Connect every Note you posted to the paid and free subscribers that actually arrived in the 24-hour window after, so you stop guessing which content drove growth.
Pick this over a generic stats call when an agent needs to decide which Note formats to repeat next week.
bash
```
substack-pp-cli growth attribution --days 30 --json --select rank,note_id,note_excerpt,subs_acquired,paid_subs_acquired
```
engage reciprocity
— See net-give/net-take per writer you engage with — who reciprocates your restacks/comments, who quietly free-rides on yours.
Use when an agent is deciding whether to keep investing in a swap partner; surfaces relationships before they go stale.
bash
```
substack-pp-cli engage reciprocity --days 30 --agent --select handle,outgoing,incoming,net,drift
```

Algorithm-aware automation

notes schedule --guard
— Refuse to fire (or queue) a Note that lands less than 30 minutes after your last own-Note or violates your time-of-day rotation. Returns typed exit 2 with a JSON diagnosis.
Stops an agent from accidentally torching its own reach by dumping a queue all at once.
bash
```
substack-pp-cli notes schedule --at 2026-05-10T13:00:00Z --body "hook line\n\nbody" --guard --json
```
growth best-time
— Top day-of-week × hour cells ranked for whichever growth signal you pick (paid subs, likes, restacks, or comments) — not a single average.
An agent picking when to schedule tomorrow's Notes can ask for the goal it's optimizing instead of guessing.
bash
```
substack-pp-cli growth best-time --days 90 --for-goal subs --json --select day_of_week,hour,rate,sample_size
```

Pattern intelligence

discover patterns
— Mechanically extracts which hook patterns (curiosity-gap colon, 3-sentence formula, em-dash reframe, question opener) actually rank in a niche, with restack/comment ratios.
An agent drafting Notes can ask which hook shape currently outperforms in this niche before generating.
bash
```
substack-pp-cli discover patterns --niche productivity --sort restacks --since 14d --agent --select pattern,sample_count,avg_restacks,avg_comments,top_example
```
voice fingerprint
— Measurable voice profile — sentence length, em-dash rate, colon-hook rate, hook-line ratios, vocabulary uniqueness — for any handle, with --diff to compare against another writer.
An agent drafting Notes for a ghostwriter client can verify the output stays inside the client's voice envelope.
bash
```
substack-pp-cli voice fingerprint --handle maya --diff devon --json --select metric,self,other,delta
```

Network leverage

recs find-partners
— Score candidate publications for a Substack Recommendations swap by mutual-overlap density across followee + recommendation graphs.
An agent running a weekly cross-promo pass can rank candidates instead of pitching cold.
bash
```
substack-pp-cli recs find-partners --my-pub on --top 20 --json --select rank,handle,pub,overlap_score,shared_followees
```
growth pod
— Given a list of handles, render a member × member engagement matrix — last 30 days of restacks/comments/likes between every pair.
An agent organizing a mutual-aid pod can see who's net-positive vs free-riding without a spreadsheet.
bash
```
substack-pp-cli growth pod --members maya,devon,priya,jordan --days 30 --json
```

Command Reference

categories — Site-wide Substack category list — culture, technology, food, etc.

```
substack-pp-cli categories list
```
— List all Substack categories

substack-pp-cli categories list-publications

— List publications in a category

comments — Long-form post comments (distinct from Notes)

```
substack-pp-cli comments get
```
— Get a single comment by ID (same shape as a Note — Substack treats them uniformly)
```
substack-pp-cli comments list
```
— List comments on a post

discover — Discovery surfaces — search publications, embed metadata

```
substack-pp-cli discover
```
— Search Substack publications by query

drafts — Drafts CRUD + publish + schedule

```
substack-pp-cli drafts create
```
— Create a new draft
```
substack-pp-cli drafts delete
```
— Delete a draft
```
substack-pp-cli drafts get
```
— Get a draft by ID
```
substack-pp-cli drafts list
```
— List drafts
```
substack-pp-cli drafts prepublish
```
— Validate a draft for publication; returns blockers
```
substack-pp-cli drafts publish
```
— Publish a draft now
```
substack-pp-cli drafts schedule
```
— Schedule a draft for future publish (or unschedule with --post-date null)
```
substack-pp-cli drafts update
```
— Update an existing draft

feed — RSS feed for a publication

```
substack-pp-cli feed
```
— RSS XML feed (returns XML; use
```
--raw
```
to dump)

images — Image upload (data-URI JSON, not multipart)

```
substack-pp-cli images
```
— Upload an image; returns CDN URL. Body is data-URI JSON.

inbox — Authenticated reader feed (home feed) — Notes + posts surfaced for the current user

```
substack-pp-cli inbox home
```
— Authenticated home feed
```
substack-pp-cli inbox reader-posts
```
— Posts feed for current user

notes — Substack Notes — short-form posts (Substack treats Notes as comments internally)

```
substack-pp-cli notes new
```
— Post a new Note from Markdown (auto-converts to ProseMirror; the agent-friendly entry point)
```
substack-pp-cli notes create
```
— Post a new Note with raw ProseMirror JSON via
```
--body-json
```
```
substack-pp-cli notes schedule
```
— Schedule a Note locally with a cadence guard (refuses bursts within 30 min; typed exit 2)
```
substack-pp-cli notes get
```
— Get a single Note by ID
```
substack-pp-cli notes list-by-profile
```
— List Notes by a profile (cursor pagination)
```
substack-pp-cli notes reply
```
— Reply to an existing Note (parent_id + ProseMirror body)

posts — Long-form posts and archives on a specific publication

```
substack-pp-cli posts archive
```
— Public archive of a publication's posts
```
substack-pp-cli posts get-by-slug
```
— Get a published post by URL slug
```
substack-pp-cli posts list-published
```
— List published posts on the publication (auth required)
```
substack-pp-cli posts ranked-authors
```
— Ranked list of authors for a publication

profiles — Substack profiles — your own and other writers'

```
substack-pp-cli profiles from-linkedin
```
— Look up a Substack profile from a LinkedIn handle
```
substack-pp-cli profiles get-by-handle
```
— Get a public profile by handle (e.g. mvanhorn)
```
substack-pp-cli profiles get-by-id
```
— Get a public profile by numeric user ID
```
substack-pp-cli profiles handle-options
```
— Available handle suggestions for the current user
```
substack-pp-cli profiles posts
```
— All posts by an author across publications
```
substack-pp-cli profiles self
```
— Get the authenticated user's profile

recommendations — Substack Recommendations — outbound (publications I recommend)

```
substack-pp-cli recommendations <publication_id>
```
— List the publications a publication recommends

sections — Sections of a publication (newsletters can have multiple)

```
substack-pp-cli sections
```
— List sections + subscriptions

settings — Account settings + connectivity probe (used by doctor)

```
substack-pp-cli settings get
```
— Get account settings
```
substack-pp-cli settings ping
```
— Connectivity probe (non-destructive PUT used by doctor)

subs — Subscriber count + publication metadata

```
substack-pp-cli subs authors
```
— List bylined authors of a publication
```
substack-pp-cli subs count
```
— Get subscriber count (read off the launch-checklist payload)

tags — Post tags

```
substack-pp-cli tags create
```
— Create a new tag
```
substack-pp-cli tags list
```
— List all tags for the publication

Freshness Contract

This printed CLI owns bounded freshness only for registered store-backed read command paths. In

--data-source auto

mode, those paths check

sync_state

and may run a bounded refresh before reading local data.

--data-source local

never refreshes.

--data-source live

reads the API and does not mutate the local store. Set

SUBSTACK_NO_AUTO_REFRESH=1

to skip the freshness hook without changing source selection.

Covered paths:

```
substack-pp-cli categories
```
```
substack-pp-cli categories list
```

substack-pp-cli categories list-publications

```
substack-pp-cli drafts
```
```
substack-pp-cli drafts create
```
```
substack-pp-cli drafts delete
```
```
substack-pp-cli drafts get
```
```
substack-pp-cli drafts list
```
```
substack-pp-cli drafts prepublish
```
```
substack-pp-cli drafts publish
```
```
substack-pp-cli drafts schedule
```
```
substack-pp-cli drafts update
```
```
substack-pp-cli inbox
```
```
substack-pp-cli inbox home
```
```
substack-pp-cli inbox reader-posts
```
```
substack-pp-cli inbox-posts
```
```
substack-pp-cli posts
```
```
substack-pp-cli posts archive
```
```
substack-pp-cli posts get-by-slug
```
```
substack-pp-cli posts list-published
```
```
substack-pp-cli posts ranked-authors
```
```
substack-pp-cli posts-published
```
```
substack-pp-cli posts-ranked
```
```
substack-pp-cli profiles
```
```
substack-pp-cli profiles from-linkedin
```
```
substack-pp-cli profiles get-by-handle
```
```
substack-pp-cli profiles get-by-id
```
```
substack-pp-cli profiles handle-options
```
```
substack-pp-cli profiles posts
```
```
substack-pp-cli profiles self
```
```
substack-pp-cli sections
```
```
substack-pp-cli subs
```
```
substack-pp-cli subs authors
```
```
substack-pp-cli subs count
```
```
substack-pp-cli tags
```
```
substack-pp-cli tags create
```
```
substack-pp-cli tags list
```

When JSON output uses the generated provenance envelope, freshness metadata appears at

meta.freshness

. Treat it as current-cache freshness for the covered command path, not a guarantee of complete historical backfill or API-specific enrichment.

Finding the right command

When you know what you want to do but not which command does it, ask the CLI directly:

bash

substack-pp-cli which "<capability in your own words>"

which

resolves a natural-language capability query to the best matching command from this CLI's curated feature index. Exit code

means at least one match; exit code

means no confident match — fall back to

--help

or use a narrower query.

Recipes

Daily growth-loop morning ritual

bash

substack-pp-cli growth attribution --days 7 --agent --select rank,note_excerpt,subs_acquired

Syncs the last 24 hours, surfaces yesterday's Note→sub winners, and shows reciprocity drift before you start engaging.

Batch-schedule a week of Notes with cadence guard

bash

substack-pp-cli notes schedule --at 2030-05-13T09:00:00Z --body 'Tuesday hook line' --guard --json

Prints every scheduled Note's request without firing; --guard rejects sub-30-min spacing. Drop --dry-run to commit.

Find this week's swap partners and draft outreach

bash

substack-pp-cli recs find-partners --my-pub on --top 5 --json --select rank,handle,pub,overlap_score

Ranks candidates by audience overlap, pipes the top 5 into the outreach drafter.

Voice-match a draft to a client (ghostwriter)

bash

substack-pp-cli voice fingerprint --handle alice --diff bob --json

Captures the client's measured voice profile as JSON, feeds it into Note generation; no LLM coupling — uses your own ANTHROPIC_API_KEY/OPENAI_API_KEY.

Surface deeply nested Note metadata with --select

bash

substack-pp-cli notes get c-12345 --agent --select id,body,attachments.url,attachments.image_url,attachments.published_bylines.name,attachments.published_bylines.handle,context.users.name

Notes responses are deeply nested (attachments, bylines, contextual users). Dotted --select narrows the payload so an agent doesn't burn context parsing 30KB of JSON it doesn't need.

Auth Setup

Substack uses a session cookie (substack.sid). The only path today is

auth login --chrome

(also accepts

--browser

as an alias) — it reads the cookie from your logged-in Chrome via pycookiecheat / cookies / cookie-scoop-cli and stores it in the OS keyring. There is no password login and no manual cookie-paste subcommand. If your cookie expires, re-run

auth login --chrome

Run

substack-pp-cli doctor

to verify setup.

Agent Mode

Add

--agent

to any command. Expands to:

--json --compact --no-input --no-color --yes

Pipeable — JSON on stdout, errors on stderr
Filterable —
```
--select
```
keeps a subset of fields. Dotted paths descend into nested structures; arrays traverse element-wise. Critical for keeping context small on verbose APIs:
bash
```
substack-pp-cli categories list --agent --select id,name,status
```
Previewable —
```
--dry-run
```
shows the request without sending
Offline-friendly — sync/search commands can use the local SQLite store when available
Non-interactive — never prompts, every input is a flag
Explicit retries — use
```
--idempotent
```
only when an already-existing create should count as success, and
```
--ignore-missing
```
only when a missing delete target should count as success

Response envelope

Commands that read from the local store or the API wrap output in a provenance envelope:

json

{
  "meta": {"source": "live" | "local", "synced_at": "...", "reason": "..."},
  "results": <data>
}

Parse

.results

for data and

.meta.source

to know whether it's live or local. A human-readable

N results (live)

summary is printed to stderr only when stdout is a terminal — piped/agent consumers get pure JSON on stdout.

Agent Feedback

When you (or the agent) notice something off about this CLI, record it:

substack-pp-cli feedback "the --since flag is inclusive but docs say exclusive"
substack-pp-cli feedback --stdin < notes.txt
substack-pp-cli feedback list --json --limit 10

Entries are stored locally at

~/.substack-pp-cli/feedback.jsonl

. They are never POSTed unless

SUBSTACK_FEEDBACK_ENDPOINT

is set AND either

--send

is passed or

SUBSTACK_FEEDBACK_AUTO_SEND=true

. Default behavior is local-only.

Write what surprised you, not a bug report. Short, specific, one line: that is the part that compounds.

Output Delivery

Every command accepts

--deliver <sink>

. The output goes to the named sink in addition to (or instead of) stdout, so agents can route command results without hand-piping. Three sinks are supported:

Sink	Effect
`stdout`	Default; write to stdout only
`file:<path>`	Atomically write output to `<path>` (tmp + rename)
`webhook:<url>`	POST the output body to the URL ( `application/json` or `application/x-ndjson` when `--compact` )

Unknown schemes are refused with a structured error naming the supported set. Webhook failures return non-zero and log the URL + HTTP status on stderr.

Named Profiles

A profile is a saved set of flag values, reused across invocations. Use it when a scheduled agent calls the same command every run with the same configuration - HeyGen's "Beacon" pattern.

substack-pp-cli profile save briefing --json
substack-pp-cli --profile briefing categories list
substack-pp-cli profile list --json
substack-pp-cli profile show briefing
substack-pp-cli profile delete briefing --yes

Explicit flags always win over profile values; profile values win over defaults.

agent-context

lists all available profiles under

available_profiles

so introspecting agents discover them at runtime.

Exit Codes

Code	Meaning
0	Success
2	Usage error (wrong arguments)
3	Resource not found
4	Authentication required
5	API error (upstream issue)
7	Rate limited (wait and retry)
10	Config error

Argument Parsing

Parse

$ARGUMENTS

Empty,
help
, or
--help
→ show
```
substack-pp-cli --help
```
output
Starts with
install
→ ends with
```
mcp
```
→ MCP installation; otherwise → see Prerequisites above
Anything else → Direct Use (execute as CLI command with
```
--agent
```
)

MCP Server Installation

Install the MCP binary from this CLI's published public-library entry or pre-built release, then register it:

bash

claude mcp add substack-pp-mcp -- substack-pp-mcp

Verify:

claude mcp list

Direct Use

Check if installed:
```
which substack-pp-cli
```
If not found, offer to install (see Prerequisites at the top of this skill).
Match the user query to the best command from the Unique Capabilities and Command Reference above.

Execute with the

--agent

flag:

bash

substack-pp-cli <command> [subcommand] [args] --agent

If ambiguous, drill into subcommand help:
```
substack-pp-cli <command> --help
```
.

pp-substack

NPX Install

Tags

SKILL.md Content

Substack — Printing Press CLI

Prerequisites: Install the CLI

When to Use This CLI

Unique Capabilities

Local state that compounds

Algorithm-aware automation

Pattern intelligence

Network leverage

Command Reference

Freshness Contract

Finding the right command

Recipes

Daily growth-loop morning ritual

Batch-schedule a week of Notes with cadence guard

Find this week's swap partners and draft outreach

Voice-match a draft to a client (ghostwriter)

Surface deeply nested Note metadata with --select

Auth Setup

Agent Mode

Response envelope

Agent Feedback

Output Delivery

Named Profiles

Exit Codes

Argument Parsing

MCP Server Installation

Direct Use