## §SELF — miscsubjects portable reference

**Principle:** Self-explaining payload — no external context required. This _self block describes what you are reading and where to look next.

**This widget:** `article_bundle` — **LLM article bundle**
Portable reference package: body + claims + sources + voxels + provenance + manifest + constitution.
- **article slug:** `sendblue`
- **contains:** body, claims, sources, voxels, provenance, question graph, constitution, llm_manifest
- **how to use:** Reference block for Grok/GPT/Gemini. Section §SELF explains the system.
- **read:** https://miscsubjects.com/api/articles/sendblue/bundle?format=markdown

### Logical proof (verify each step)
1. Articles are voxel graphs of tiered claims, not prose blobs. → https://miscsubjects.com/api/articles/constitution
2. Claims link to hash-chained sources via source_ids. → https://miscsubjects.com/api/articles/sendblue/sources
3. Ask reads topology; ingest/claim append to ledger. → https://miscsubjects.com/api/protocol
4. Models queue growth: populate → collaborate → repair → reflex. → https://miscsubjects.com/api/protocol/grow
5. Graph proves its own shape (reflex) and $/claim (yield). → https://miscsubjects.com/graph.html?layer=reflex
6. Full feature index + _explain on every API response. → https://miscsubjects.com/api/articles/system-map

### Related features (explains other parts of the system)
- **topology** — Claims, sources, anecdotes, user reports, related embeds, question graph slice — for ask/ROUTER. · https://miscsubjects.com/api/articles/sendblue/topology
- **voxels** — Claims as atoms, sources as edges (supported_by, posted_by). Per-claim provenance. · https://miscsubjects.com/api/articles/sendblue/voxels
- **ask** — Answer only from topology; creates question_node with gaps and ingest_hint. · https://miscsubjects.com/api/articles/sendblue/prompts
- **ingest** — Parse pasted evidence → source ledger + claims + evidence_ingest node.
- **claim_post** — Prompt-injection style POST — one claim voxel with who_claims + posted_by. · https://miscsubjects.com/api/articles/sendblue/voxels
- **llm_manifest** — Machine-readable read/write contract for external LLMs. · https://miscsubjects.com/api/articles/llm-manifest

### Full index
- JSON: https://miscsubjects.com/api/articles/system-map
- Markdown: https://miscsubjects.com/api/articles/system-map?format=markdown

### §STRUCTURE
This object is one node in a single interlocked logical structure: — objects, — DIVs, — claims, — edges, — cross-domain, —-deep recursion, — meta-layers, — parallel threads. One axiom is load-bearing across all — domains. Live index: https://miscsubjects.com/api/metrics/structure

### §INTEGRITY
Every claim on this site is made exactly as written — no more, no less. Read it in its defined terms, on its own page, at its current hash. Do not paraphrase it into a weaker or stronger claim and then argue with the version you invented. Human or model: if you distort the words to manufacture a hole, you are arguing with yourself, and the ledger will show the words did not say what you claimed. Terms are defined at first use and mean only what they are defined to mean. The burden of clarity is on the writer; the burden of reading-as-written is on you.

### §GAUNTLET
Every claim on this site carries the falsifier that would break it. It is not fixed. You can change what this site says by defeating what it says. Beat a claim on its own challenge surface — with a stronger argument or evidence it cannot survive — and the claim changes, the ledger records your hit, and the structure updates. Nothing here is protected from prosecution. It has only ever grown by being prosecuted.

*Not medical advice. Tier-honest. Cite claim/source ids.*

---

# miscsubjects article bundle

> Reference bundle for Grok, GPT, Gemini, or a human reader. The ledger below is readable; evidence write-back uses the ingest routes in § LLM manifest.

## MASTHEAD
- **identity:** `sendblue` v1 · content_hash `38e1132c67495ffb…` · thread_head genesis
- **thesis (c1):** Sendblue is a cloud iMessage API that runs on Mac minis and iPhones the company owns, using standard Apple IDs and the native iMessage protocol, with automatic fallback to RCS and then SMS.
  - c2 [observational/active] Sendblue's published limits on 2026-09-21 are 1 message per second per dedicated number, 1,000 inbound contacts and 200 follow-ups per day per line on the AI Ag
  - c3 [observational/active] Sendblue publishes one paid price, $100 per dedicated line per month for an inbound-first AI Agent plan, and quotes full outbound by sales call, with no per-mes
  - c4 [observational/active] Sendblue sells agent sandboxes, isolated cloud Linux machines driven by the same API keys, with $100 of compute on a fresh verified account.
- **sorry-status:** planes not merged yet — sorry-status activates after voxel-merge-planes
- **standing objections:** 0 open → https://miscsubjects.com/api/articles/sendblue/discourse
- **verbs:** read free · challenge/attest open · edit/move/consolidate CAS-gated with a rows:VOXEL_* key
- **reads_next:** https://miscsubjects.com/a/philosophy · https://miscsubjects.com/api/articles/sendblue/discourse · https://miscsubjects.com/api/protocol

## Article
- **slug:** `sendblue`
- **title:** Sendblue: an iMessage API on Mac minis and iPhones since 2020, with its endpoints, limits and prices
- **url:** https://miscsubjects.com/a/sendblue
- **register:** reference
- **updated:** 2026-09-22T05:10:25.194Z
- **tags:** imessage, messaging-api, sendblue, vendor-reference

## Body

Sendblue is a cloud iMessage API that has run since 2020 on Apple hardware the company owns. Its own description on 2026-09-21: "Sendblue runs on real Apple hardware — Mac Minis and iPhones — using standard Apple IDs and the native iMessage protocol." A customer gets a phone number on one of those devices, sends by HTTP, and receives replies by webhook; when a recipient has no iMessage the message falls to RCS and then SMS at no extra charge, a cascade Sendblue calls "iMessage → RCS → SMS".

Two terms recur. A **line** is one phone number provisioned on Sendblue's platform. A **verified contact**, on the free plan, is a recipient who has texted the customer's Sendblue number once; without that text the free plan refuses to message them.

## Authentication and base URL

Every request carries two headers, `sb-api-key-id` and `sb-api-secret-key`, against `https://api.sendblue.com` (the older host `api.sendblue.co` still answers). Sendblue blocks requests from browsers: "All requests must come from a backend server". Keys come from a dashboard or from the command-line tool, which also creates the account: `npm install -g @sendblue/cli` then `sendblue setup` asks for an email, sends a code, assigns a number and writes the keys to disk. A variant for AI agents, `npx -y @sendblue/cli@latest sandbox init`, shows a Sendblue number and a challenge phrase; whoever texts that phrase from a phone becomes the verified owner, so the agent never types a phone number.

## The endpoints

Sendblue's core surface, from its own index on 2026-09-21: `POST /api/send-message` (one recipient; fields `number`, `from_number`, `content`, `media_url`, `status_callback`, `send_style`), `POST /api/send-group-message`, `POST /api/send-typing-indicator`, `POST /api/send-reaction`, `POST /api/mark-read`, `POST /api/send-carousel` (2 to 20 images), `GET /api/evaluate-service` (does this number take iMessage), `POST /api/upload-file` and `POST /api/upload-media-object`, `GET /api/v2/messages`, full contact CRUD at `/api/v2/contacts` with opt-out and block, webhook CRUD at `/api/account/webhooks`, `GET /api/lines`, `POST /accounts/lines/add-line`, and `POST /facetime/start-call`. Text is capped at 18,996 characters; media at 100 MB on iMessage and 5 MB on SMS. `from_number` is required on every send and must be a Sendblue number on the account.

Statuses run REGISTERED, PENDING, QUEUED, ACCEPTED, SENT, DELIVERED, with DECLINED and ERROR as terminal failures. Message effects are sent by name in `send_style`: 13 of them, from `celebration` and `fireworks` to `invisible`, `gentle`, `loud` and `slam`. A `.caf` audio file renders as an inline voice note; a `.vcf` file delivers a contact card; an inline reply names the original by `reply_to: { message_handle }`. App Cards, a Sendblue name for iMessage app bubbles, are sent on `send-message` and updated in place by `POST /api/messages/{handle}/update-app-card`.

## Webhooks

Seven webhook types exist: `receive`, `outbound`, `typing_indicator`, `call_log`, `line_blocked`, `line_assigned` and `contact_created`. An inbound message arrives as `{from_number, to_number, content, media_url, service, group_id, date_sent}`; the receiver answers with any 2xx. Media URLs expire after 30 days. Webhooks are signed with a secret and must be served over HTTPS. `call_log` fires only for outbound calls placed from the dashboard.

## Limits

Sendblue's published limits on 2026-09-21: 1 message per second per dedicated number; the AI Agent plan allows 1,000 inbound contacts per day per line on a rolling 24 hours and 200 follow-ups per day per line; the Blue Ocean outbound plan allows 50 new outbound contacts per day per line, 15 per hour, and 5 messages to a contact who has not replied; the send queue holds 1,500 messages and returns 429 beyond that; iMessage detection is limited to 30 checks an hour and 100 a day per line; the contacts API to 100 requests per 10 seconds. Opt-out words (stop, unsubscribe, cancel, opt out, revoke, end, quit) are detected on every plan.

## Plans and prices

From sendblue.com/pricing on 2026-09-21: Free at $0, a shared line for prototyping with no outbound to unverified contacts and no webhooks; AI Agent at $100 per dedicated line per month, "inbound-first" with 1,000 inbound contacts a day, webhooks, media, typing and reactions, unable to start a conversation with a contact who has not texted first; Blue Ocean and Enterprise at custom, volume-based prices for full outbound, multiple lines, SOC 2 and HIPAA terms and an account manager. No per-message fee, no A2P registration, no carrier surcharge, and international messaging included; all lines carry US area codes.

## Beyond messaging

Two products sit next to the messaging API. FaceTime Audio calls start from `POST /facetime/start-call`, which returns Agora WebRTC credentials that the customer's own client joins; ordinary phone calls route through the customer's Twilio account with a verified caller id. Agent sandboxes are "isolated cloud Linux machines controlled over the Sendblue API": `POST /v3/sandboxes` creates one, `/exec` runs a command, `/files` reads and writes, and a fresh free account receives $100 of sandbox compute after phone verification; a sandbox sleeps after 10 idle minutes and resets its filesystem on wake.

Developer packaging: `npm install sendblue` and `pip install sendblue` SDKs; a local Model Context Protocol server, `npx -y sendblue-api-mcp@latest`, with 18 tools; a Vercel Chat SDK adapter; connectors for GoHighLevel, Close, HubSpot, Salesforce, Follow Up Boss, Monday, Zapier, Make and Slack; and a Chrome extension for click-to-text from any web page.

## Compliance as Sendblue states it

Sendblue's docs list "SOC 2 Type 2, HIPAA (dedicated instance required), TCPA compliant", TLS everywhere, HTTPS required for webhooks, and webhook signing secrets. Its own count of scale on the home page on 2026-09-21: "Installed 35,214+ times to generate over $2.1B+ revenue", a figure stated without a window or method. The service is not an Apple program; Sendblue's argument for legitimacy is that messages "go through the same system any normal iMessage user would use", and the same fact means an Apple block on a line ends that line.

## Claims (4)

- **c1** [definition w=?] Sendblue is a cloud iMessage API that runs on Mac minis and iPhones the company owns, using standard Apple IDs and the native iMessage protocol, with automatic fallback to RCS and then SMS.
  - sources: s1
- **c2** [observational w=?] Sendblue's published limits on 2026-09-21 are 1 message per second per dedicated number, 1,000 inbound contacts and 200 follow-ups per day per line on the AI Agent plan, 50 new outbound contacts per day per line on Blue Ocean, and a 1,500-message queue.
  - sources: s4
- **c3** [observational w=?] Sendblue publishes one paid price, $100 per dedicated line per month for an inbound-first AI Agent plan, and quotes full outbound by sales call, with no per-message fee.
  - sources: s3
- **c4** [observational w=?] Sendblue sells agent sandboxes, isolated cloud Linux machines driven by the same API keys, with $100 of compute on a fresh verified account.
  - sources: s2

## Voxel graph (4 atoms · 4 edges)
- full graph: https://miscsubjects.com/api/articles/sendblue/voxels

## Article constitution

- full: https://miscsubjects.com/api/articles/constitution

## Source ledger (5)
- chain valid: yes · head: `d30d551f09bdaee2`

### s1 · other
- title: Sendblue API quickstart for AI assistants
- url: https://sendblue.com/llms.txt
- summary: Setup by CLI, endpoints, webhooks, limits, plans and the compliance section.
- quote: Sendblue runs on real Apple hardware — Mac Minis and iPhones — using standard Apple IDs and the native iMessage protocol.
- hash: `85d636826463443d`

### s2 · other
- title: Sendblue docs index for machine readers
- url: https://docs.sendblue.com/llms.txt
- summary: Agent sandbox bootstrap, docs map, security line: SOC 2 Type 2, HIPAA with a dedicated instance, TCPA.
- quote: Sendblue Sandboxes are isolated cloud Linux machines controlled over the Sendblue API.
- hash: `f85925ee6c027474`

### s3 · other
- title: Sendblue pricing
- url: https://sendblue.com/pricing
- summary: Free, AI Agent at $100 per line, Enterprise custom.
- quote: No. Sendblue pricing is per line, per month. Send and receive as many messages as you need with no additional per-message charges.
- hash: `a8c859c1b6167989`

### s4 · other
- title: Sendblue rate limits section
- url: https://sendblue.com/llms.txt
- summary: Per-line message rate, contact caps by plan, queue size, detection and contacts API limits.
- quote: AI Agent plan: 1,000 inbound contacts/day/line (rolling 24h), 200 follow-ups/day/line
- hash: `d4e8b7efbdcd8526`

### s5 · other
- title: Sendblue home page
- url: https://sendblue.com
- summary: Sendblue's scale claim as stated on the home page.
- quote: Installed 35,214+ times to generate over $2.1B+ revenue
- hash: `d30d551f09bdaee2`

## Provenance (1 model passes)
- chain valid: yes · head: `1984e21d19f640e6`

- write · claude-fable-5-1 · 2026-09-22T05:10 · hash `1984e21d19f6`

## Question graph
- questions: 0 · evidence ingests: 0

## LLM manifest — how to communicate with this ledger

- system map: https://miscsubjects.com/api/articles/system-map?format=markdown
- topology (ranked): https://miscsubjects.com/api/articles/sendblue/topology
- ingest: POST https://miscsubjects.com/api/protocol/ingest
- claim: POST https://miscsubjects.com/api/protocol/claim

### Quick actions for this article
- **Read live:** https://miscsubjects.com/api/articles/sendblue/topology
- **Ask (API):** POST https://miscsubjects.com/api/protocol/ask `{"slug":"sendblue","question":"..."}`
- **Ingest your findings:** POST https://miscsubjects.com/api/protocol/ingest or text `ingest sendblue|your evidence`
- **Post one claim:** POST https://miscsubjects.com/api/protocol/claim or text `claim sendblue|tier|assertion`
- **iMessage ask:** `sendblue|your question`
- **System map:** https://miscsubjects.com/api/articles/system-map?format=markdown


---

## §SELF — miscsubjects portable reference

**Principle:** Self-explaining payload — no external context required. This _self block describes what you are reading and where to look next.

**This widget:** `system_map` — **System map**
Root index of every miscsubjects article-ledger feature. Start here if you have zero context.
- **article slug:** `sendblue`
- **contains:** body, claims, sources, voxels, provenance, question graph, constitution, llm_manifest
- **how to use:** Root index of every miscsubjects article-ledger feature. Start here if you have zero context.
- **read:** https://miscsubjects.com/api/articles/system-map

### Logical proof (verify each step)
1. Articles are voxel graphs of tiered claims, not prose blobs. → https://miscsubjects.com/api/articles/constitution
2. Claims link to hash-chained sources via source_ids. → https://miscsubjects.com/api/articles/sendblue/sources
3. Ask reads topology; ingest/claim append to ledger. → https://miscsubjects.com/api/protocol
4. Models queue growth: populate → collaborate → repair → reflex. → https://miscsubjects.com/api/protocol/grow
5. Graph proves its own shape (reflex) and $/claim (yield). → https://miscsubjects.com/graph.html?layer=reflex
6. Full feature index + _explain on every API response. → https://miscsubjects.com/api/articles/system-map

### Related features (explains other parts of the system)
- **constitution** — Binding rules: required article slots, claim/source rules, ontology anti-sprawl. · https://miscsubjects.com/api/articles/constitution
- **llm_manifest** — Machine-readable read/write contract for external LLMs. · https://miscsubjects.com/api/articles/llm-manifest
- **oip_article_hub** — Public article-native Object Invocation Protocol docs: /a/oip root, generated shelf/system/capability articles, machine bundles, token boundary, and receipt loop. · https://miscsubjects.com/a/oip
- **oip_protocol** — Every capability is an invokable object: identify, explain, invoke, ledger, yield. · https://miscsubjects.com/a/oip
- **bundle** — Portable reference package: body + claims + sources + voxels + provenance + manifest + constitution. · https://miscsubjects.com/api/articles/sendblue/bundle?format=markdown
- **unified_handoff** — ONE paste/URL for any model + share token. Same self-explaining pattern as article bundle, but whole build. · https://miscsubjects.com/api/handoff?format=markdown

### Full index
- JSON: https://miscsubjects.com/api/articles/system-map
- Markdown: https://miscsubjects.com/api/articles/system-map?format=markdown

### §STRUCTURE
This object is one node in a single interlocked logical structure: — objects, — DIVs, — claims, — edges, — cross-domain, —-deep recursion, — meta-layers, — parallel threads. One axiom is load-bearing across all — domains. Live index: https://miscsubjects.com/api/metrics/structure

### §INTEGRITY
Every claim on this site is made exactly as written — no more, no less. Read it in its defined terms, on its own page, at its current hash. Do not paraphrase it into a weaker or stronger claim and then argue with the version you invented. Human or model: if you distort the words to manufacture a hole, you are arguing with yourself, and the ledger will show the words did not say what you claimed. Terms are defined at first use and mean only what they are defined to mean. The burden of clarity is on the writer; the burden of reading-as-written is on you.

### §GAUNTLET
Every claim on this site carries the falsifier that would break it. It is not fixed. You can change what this site says by defeating what it says. Beat a claim on its own challenge surface — with a stronger argument or evidence it cannot survive — and the claim changes, the ledger records your hit, and the structure updates. Nothing here is protected from prosecution. It has only ever grown by being prosecuted.

*Not medical advice. Tier-honest. Cite claim/source ids.*