Get started with Blocx
Your path from business registration to a working SMS and MMS integration. Prepare your 10DLC brand and campaign, connect your sender, and test the complete conversation.
Starting with US local business texting? Follow this guide to prepare your 10DLC setup and connect Blocx to your application. Already sending elsewhere? Use the migration checklist before changing production traffic.
Choose your setup
Start with your use case and the right sender type.
Decide what your application will send, who will receive it, and how recipients give permission. This guide focuses on US local 10DLC SMS and MMS; toll-free and short-code senders have different requirements.
Create your Blocx account using Get started, review the current plans, and decide whether self-serve Starter or a conversation about Scale or Volume fits your needs. Check the full rate card and applicable registration, number and carrier charges before budgeting.
Register your brand
Have accurate business details ready for your brand.
A 10DLC brand identifies the business responsible for the messages. Prepare the legal business name, business address, working website, business contact information, and tax or registration identifier where required for your entity and registration route.
Make those details consistent with the business records and website. Work through Blocx's current onboarding process for your brand; submitting information is not the same as receiving approval.
- Legal business details and applicable tax identifier
- Live business website and contact information
- Public privacy policy and terms appropriate to your service
Define your campaign
Describe the actual messages—not just the product category.
A campaign describes your messaging use case and how customers opt in. Prepare a clear description, representative message samples, the opt-in flow, and the relevant privacy and terms links.
Keep marketing, transactional and authentication intent clear. A purchase, an email subscription or possession of a phone number does not automatically establish permission for marketing texts. Include how customers can opt out and get help.
Use Blocx's current registration flow and address any requested corrections. Wait for the required approval and sender readiness before launching live campaign traffic.
- Accurate use-case description and sample messages
- Evidence of the actual opt-in flow
- Opt-out and help handling for the intended traffic
Connect your number
Make sure your sender is ready for its approved campaign.
Coordinate number provisioning and campaign assignment through Blocx's current onboarding process. Before sending production 10DLC traffic, confirm that the number is connected to the approved campaign and ready for the intended use case.
If you already own a number or have an existing registration, discuss the available migration path with Blocx first. Eligibility, authorization, timing and any costs depend on the current setup and the parties involved.
Connect your application
Use the official SDK and keep credentials on your server.
Install the official @otterlabs/blocx JavaScript/TypeScript SDK, then follow the current SDK example and API reference for client setup and the exact send request. Keep your access key ID and secret access key in server-side environment variables.
Never embed provider credentials in a browser bundle, a public repository or a customer-facing example. Use the documented test-phone sandbox while wiring the integration; sandbox results do not establish live carrier delivery or production approval.
Send a test message
Test with a permitted recipient and a ready sender.
Once your account, registration and sender are ready, send a short test SMS to a phone you control or another authorized, opted-in test recipient. Use your actual provisioned sender and the request format in the documentation.
Record the returned message identifier and inspect the delivery events. A successful API submission is not proof that the phone received the message. If you plan to send MMS, also test a supported media attachment using the documented format.
Test replies and events
Make sure the conversation works in both directions.
Configure the documented inbound SMS/MMS and delivery webhooks, verify their signatures using the current contract, and connect events to the right customer and message in your application.
Reply from your test phone and confirm the inbound event reaches your backend. Make repeated callbacks safe to process and distinguish a customer reply from a delivery-status update.
Launch with guardrails
Prove the failure paths before increasing traffic.
Test the applicable STOP and HELP behavior, suppression rules, failed deliveries and retries. Preserve consent context, cancel queued follow-ups when someone opts out, and respect account limits, carrier requirements and applicable sending-time rules.
Set a monthly spend cap and application-level usage controls, monitor delivery and errors, and increase traffic within the approved use case and documented limits. Keep transactional notifications and marketing campaigns distinguishable.
- Opt-outs stop the relevant future sends
- Replies and delivery events reach the correct records
- Retry handling does not create accidental duplicates
- Budgets, monitoring and escalation are in place
Install the official SDK
npm install @otterlabs/blocxAlready have brands, campaigns or numbers?
Bring your existing setup to the conversation before moving it. A migration plan should account for registration, sender readiness and the application integration—not just changing an API URL.
- Inventory your existing numbers, brands, campaigns, consent records and callback integrations. Share only the information needed through an appropriate onboarding channel; never put credentials in public forms or documentation.
- Confirm with Blocx what can transfer or be reused, which authorizations or reviews are required, and the applicable costs and timing. Existing approval does not by itself guarantee an immediate or fee-free migration.
- If you are a CSP, reseller or software platform, agree on the supported account and registration structure before moving customers. Do not assume another provider's group hierarchy or TCR connectivity arrangement applies to Blocx.
- Validate outbound messages, replies and delivery events before a controlled cutover. Keep the existing service active until the replacement is ready, and agree on a rollback plan where applicable.
Getting started questions
Can I test before my campaign is approved?
Use the documented sandbox to develop and test supported scenarios. Sending live campaign traffic still requires the applicable account, registration and sender readiness. Sandbox success is not a carrier approval.
Can I bring an existing number or campaign?
Discuss your current provider, number and registration setup with Blocx. Transfer or reuse depends on eligibility, authorizations and review; do not cancel the existing service before the cutover is ready.
Does 10DLC registration cover toll-free and short code?
No. This guide focuses on US local 10DLC messaging. Toll-free and short-code senders follow different processes; review the sender guide or discuss your requirements with Blocx.
Is this an SDK for voice calls too?
The official messaging SDK supports messaging, email and verification, not Voice calls. Blocx Voice services are separate; contact the team for access.
Resources
Brand identity
Blocx is the programmable messaging product from OtterBlocx, LLC, headquartered in Cheyenne, Wyoming, United States.
Channels
- Live today: SMS, MMS, RCS, Email, Telegram.
- Blocx also offers separate Voice services: VoIP, voicemail, call routing, 2FA via AI caller, and a voice dialer. These are not channels on the messaging or Verify API.
Plans
- Starter — self-serve with $25 in welcome credit for new accounts. Credit covers your first brand, campaign, phone numbers and messages. Paid Starter is $49/month credited toward usage. SMS $0.0065/segment, email $0.001/email (1 sending domain), 1 API key. No MMS, RCS, Telegram, SHAFT or restricted verticals.
- Scale — $1,000/month minimum platform spend (starts on day 31; no minimum for the first 30 days), on an annual contract. Every channel and route type at the published rate card — all rates listed on this site are Scale rates. Signup starts with a call. Required tier for SHAFT and other restricted verticals.
- Volume — custom volume-based pricing negotiated on your traffic profile. Contact sales.
Published rate card (+ carrier passthrough on SMS/MMS)
- SMS: 10DLC $0.0045, toll-free $0.0055, short code $0.007.
- MMS: 10DLC $0.0135, toll-free $0.016, short code $0.018.
- RCS: $0.0135/msg + one-time $1,000 setup fee.
- Email: $0.0002 per email, flat.
- Verify: $0.035 per successful verify, flat.
- Telegram: $0.0045/msg, flat.