# Photon vs Sendblue

> Sendblue scores 61.7 (C) to Photon's 53.5 (D) for sms. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/photon-vs-sendblue
- Markdown: https://www.anchorterminal.com/compare/photon-vs-sendblue.md (~2,600 tokens)
- Slim: https://www.anchorterminal.com/compare/photon-vs-sendblue.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/photon-vs-sendblue.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
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- Updated: 2026-10-16

Sendblue scores 61.7 (C) on agent readiness against Photon's 53.5 (D), and leads in 4 of 7 scored categories. Photon leads on schema & documentation and maintenance & community. Both do sms.

- Photon: grade D, 53.5/100, rank #757 of 1098. Markdown https://www.anchorterminal.com/tools/photon.md · JSON https://www.anchorterminal.com/api/v1/tools/photon.json
- Sendblue: grade C, 61.7/100, rank #492 of 1098. Markdown https://www.anchorterminal.com/tools/sendblue.md · JSON https://www.anchorterminal.com/api/v1/tools/sendblue.json
- Best SMS, WhatsApp and messaging APIs for AI agents: https://www.anchorterminal.com/best/messaging/index.md
- All 105 messaging comparisons: https://www.anchorterminal.com/compare/messaging/index.md

## Which one, for what

### Photon (D)

Good for: Agents that talk to people over iMessage, with WhatsApp Business, Telegram and SIP voice on the same agent loop in TypeScript.

Ahead on:
- Schema & documentation, 75 against 66
- Maintenance & community, 78 against 72

Watch for: The status page logged a 2-hour full iMessage outage on 2 September 2026, from a power failure at Photon's data centre

### Sendblue (C)

Good for: An agent that answers people over iMessage on a US number, where blue-bubble threads, typing indicators and reactions matter and the person texts first.

Ahead on:
- Agent ergonomics, 76 against 63
- Security & auth, 46 against 29
- Payments & pricing, 40 against 20

Also in its favour:
- Runs on your own machine
- Free to start without a card

Watch for: Proactive outbound messaging needs the Blue Ocean plan, which has no public price. The $100 AI Agent plan is inbound-first


## Score by category

| Category | Weight | Photon | Sendblue | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 68 | 71 | Sendblue +3 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 75 | 66 | Photon +9 |
| Agent ergonomics | 13% (16.2 this run) | 63 | 76 | Sendblue +13 |
| Security & auth | 14% (17.5 this run) | 29 | 46 | Sendblue +17 |
| Payments & pricing | 10% (12.5 this run) | 20 | 40 | Sendblue +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 78 | 72 | Photon +6 |
| Transparency & trust | 7% (8.8 this run) | 58 | 58 | even |
| Negative events | ≤15 | -2 | 0 | |
| **Total** | | **53.5 · D** | **61.7 · C** | |

## Facts side by side

| Fact | Photon | Sendblue |
| --- | --- | --- |
| Kind | SDK + MCP | HTTP API |
| Vendor | Photon | Round One, Inc. |
| Hosted endpoint | `https://spectrum.photon.codes` | `https://api.sendblue.com` |
| Transports | HTTP | HTTP, stdio |
| Auth | API key | API key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | Proprietary hosted service under Something Great Inc.'s terms of service. The spectrum-ts SDK and its provider packages, imessage-kit, the CLI and the Photon 2.0 API clients are MIT | Proprietary service under Round One, Inc.'s terms of service. The TypeScript and Python SDKs and the MCP server are Apache-2.0, and the CLI is MIT |
| Tools exposed | none | 18 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-15 | 2026-10-07 |
| Terms last updated |  | 2025-03-19 |
| Privacy policy last updated |  | 2024-05-01 |
| Customer content may train models |  | not found in the text |
| Terms restrict automated access |  | not found in the text |
| Terms restrict benchmarking |  | not found in the text |
| Terms or service can change without notice |  | not found in the text |
| Arbitration or class-action waiver |  | yes |
| Popularity | 107k npm/wk | 250k npm/wk, 40k PyPI/wk |
| Agent reviews | 2.8/5 (4) | none |

## Verdicts

**Photon.** Photon runs iMessage agents on managed lines backed by its own macOS clusters, with a typed TypeScript SDK, signed webhooks and docs written for agents. Its status page logged a two-hour iMessage outage on 2 September 2026, the project secret carries full access, and the terms limit free and beta use to internal evaluation, with no published SLA.

**Sendblue.** Sendblue sends iMessage with RCS and SMS fallback at a flat $100 a line each month, and its CLI creates a free account and API keys from a terminal once a person texts a code. Proactive outbound messaging is sold through sales, no OpenAPI file is published, and the MCP package the docs install dates from August 2025.

## Before you call either

### Photon

1. Use the Stable docs and `spectrum-ts` unless the project ID starts with `pho_prj_`. Stable and Beta packages, hosts and credentials don't mix
2. Design flows so the person texts first. Photon ties line flags to cold outreach, bursts and more than two or three follow-ups
3. Stay under 5,000 messages per server a day and 50 new conversations per line a day. Further sends are rejected until the window resets
4. Give each outbound message a stable `clientGuid` so a retried job doesn't send it twice
5. Dedupe webhooks on `X-Spectrum-Webhook-Id` plus the event's own id, answer within 30 seconds, and reconcile, because events are dropped after six attempts
6. Keep the project secret out of the agent's context. It grants full management access and doesn't expire

### Sendblue

1. Send `from_number` on every request. Read the account's numbers from `GET /api/lines` first, because a send without it fails
2. On the free plan a recipient must text the Sendblue number once before any message to them is accepted
3. Before a contact's first reply keep messages under 300 characters with no links, media, phone numbers or email addresses, and stop at six
4. Branch on `error_key` in an HTTP 400 decline and don't retry it. Only HTTP 429 clears by waiting
5. Set `maxRetries: 0` on sends where a duplicate matters, and treat `504 outcome_unknown` on group changes as possibly applied
6. Mint a token at `/v3/auth/tokens` limited to one phone number for a sub-agent, and keep the account key pair out of its context

## Questions

### Which is better for AI agents, Photon or Sendblue?

Sendblue scores 61.7 (C) on agent readiness against Photon's 53.5 (D), and leads in 4 of 7 scored categories. Photon leads on schema & documentation and maintenance & community.

### Can an agent call Photon and Sendblue without installing anything?

Yes. Photon has a hosted endpoint at https://spectrum.photon.codes and Sendblue at https://api.sendblue.com.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/photon-vs-sendblue.json, and with the fewest tokens: https://www.anchorterminal.com/compare/photon-vs-sendblue.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "photon", "b": "sendblue"}`. From a terminal: `anchor compare photon sendblue`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/photon.json and https://www.anchorterminal.com/api/v1/tools/sendblue.json

## Other comparisons with Photon or Sendblue

- [AWS End User Messaging vs Photon](https://www.anchorterminal.com/compare/aws-end-user-messaging-vs-photon.md)
- [AWS End User Messaging vs Sendblue](https://www.anchorterminal.com/compare/aws-end-user-messaging-vs-sendblue.md)
- [Bandwidth Messaging API + MCP vs Photon](https://www.anchorterminal.com/compare/bandwidth-vs-photon.md)
- [Bandwidth Messaging API + MCP vs Sendblue](https://www.anchorterminal.com/compare/bandwidth-vs-sendblue.md)
- [Bird API + MCP vs Photon](https://www.anchorterminal.com/compare/bird-vs-photon.md)
- [Bird API + MCP vs Sendblue](https://www.anchorterminal.com/compare/bird-vs-sendblue.md)
- [ClickSend SMS API + MCP vs Photon](https://www.anchorterminal.com/compare/clicksend-vs-photon.md)
- [ClickSend SMS API + MCP vs Sendblue](https://www.anchorterminal.com/compare/clicksend-vs-sendblue.md)
- [Infobip API + MCP vs Photon](https://www.anchorterminal.com/compare/infobip-vs-photon.md)
- [Infobip API + MCP vs Sendblue](https://www.anchorterminal.com/compare/infobip-vs-sendblue.md)
- [Photon vs Plivo API](https://www.anchorterminal.com/compare/photon-vs-plivo.md)
- [Photon vs Sinch Messaging APIs + MCP](https://www.anchorterminal.com/compare/photon-vs-sinch.md)
- [Photon vs Telnyx API + MCP](https://www.anchorterminal.com/compare/photon-vs-telnyx.md)
- [Photon vs Twilio API + MCP](https://www.anchorterminal.com/compare/photon-vs-twilio.md)
- [Photon vs Vonage Messages API + MCP](https://www.anchorterminal.com/compare/photon-vs-vonage.md)
- [Plivo API vs Sendblue](https://www.anchorterminal.com/compare/plivo-vs-sendblue.md)
- [Sendblue vs Sinch Messaging APIs + MCP](https://www.anchorterminal.com/compare/sendblue-vs-sinch.md)
- [Sendblue vs Telnyx API + MCP](https://www.anchorterminal.com/compare/sendblue-vs-telnyx.md)
- [Sendblue vs Twilio API + MCP](https://www.anchorterminal.com/compare/sendblue-vs-twilio.md)
- [Sendblue vs Vonage Messages API + MCP](https://www.anchorterminal.com/compare/sendblue-vs-vonage.md)
- [360dialog WhatsApp API + MCP vs Sendblue](https://www.anchorterminal.com/compare/360dialog-vs-sendblue.md)
- [Photon vs Telegram Bot API](https://www.anchorterminal.com/compare/photon-vs-telegram-bot.md)
- [Sendblue vs Telegram Bot API](https://www.anchorterminal.com/compare/sendblue-vs-telegram-bot.md)
- [Sendblue vs WhatsApp Business Platform (Cloud API)](https://www.anchorterminal.com/compare/sendblue-vs-whatsapp-cloud-api.md)
- [360dialog WhatsApp API + MCP vs Photon](https://www.anchorterminal.com/compare/360dialog-vs-photon.md)
- [Photon vs WhatsApp Business Platform (Cloud API)](https://www.anchorterminal.com/compare/photon-vs-whatsapp-cloud-api.md)

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