# coss.com

> One API key and one SDK for transactional and marketing email, SMS, Hooks (webhooks as a service for your own users) and Risk (sign-up, login and payment risk decisions). These docs are written for people and coding agents alike.

## Reading these docs

- Every page is Markdown at its URL plus `.md`, as linked below (the docs home is https://coss.com/docs/index.md). Fetch the pages you need rather than guessing.
- API reference pages (https://coss.com/docs/api-reference/…) give each operation's method and URL, parameters, request body, responses and errors, with TypeScript, HTTP, Python, Go, Ruby, PHP, Java and .NET examples. The OpenAPI 3.1 document is https://api.coss.com/openapi.json.
- https://coss.com/llms-full.txt is every guide in one file, with one short entry per API operation.
- Claude Code plugin, an Agent Skill for other agents, and the MCP server: https://coss.com/docs/agents.md.

## Adding coss.com to a project

1. **Get a development API key.** In the project's directory, run `npx coss-cli init` and tell the user to expect a browser window: it opens the coss.com dashboard, where they sign in and approve a key for this project (it waits up to 5 minutes). It then writes the key to `.env.local` (Next.js) or `.env` as `COSS_API_KEY`, and installs the `coss` package in JavaScript projects. A key already in that file is kept: check it starts with `coss_test_` (`--force` replaces it). Where no browser can open (over SSH, in a container or a cloud sandbox) it prints a link and waits for a code typed into the terminal, so ask the user to run it there themselves. `--agents` also writes a short version of these notes into the project's AGENTS.md. See https://coss.com/docs/cli.md.
2. **Build and test with that key.** Development keys (`coss_test_…`) work with every API, record every email and SMS with their events and webhooks, and deliver nothing; the simulator addresses and numbers produce bounces, complaints and failures (https://coss.com/docs/environments.md). Never ask for a live key (`coss_live_…`) to develop with: going live (a verified domain, a registered number, a production key) is the user's step, in the dashboard.
3. **Use the SDK.** TypeScript: `import { Coss } from "coss"`; `new Coss()` reads `COSS_API_KEY`. Every method returns `{ data, error }` and never throws for API or network failures, so check `error` (`type`, `code`, `message`); retries are automatic and safe (an `Idempotency-Key` on every POST). See https://coss.com/docs/quickstart.md and https://coss.com/docs/sdk.md. Python, Go, Ruby, PHP, Java and .NET SDKs: https://coss.com/docs/sdks.md. Nodemailer, Better Auth, Auth.js, Laravel, Rails and Django: https://coss.com/docs/integrations.md.
4. **Receive webhooks.** Verify every request with `verifyWebhook(rawBody, headers, secret)`, which throws on a bad signature (https://coss.com/docs/sdk/webhooks.md; events: https://coss.com/docs/webhooks.md). Locally, `npx coss-cli listen --forward-to localhost:3000/<path>` forwards the environment's events to the handler and `npx coss-cli trigger <event type>` sends a sample one. These commands use the CLI's own sign-in (`npx coss-cli login`, approved like `init`) or `COSS_API_KEY` in their environment.
5. **Check what happened.** `npx coss-cli logs tail` follows the environment's API requests and events, and `npx coss-cli emails diagnose <id>` explains a delivery. The MCP server (`npx -y coss-mcp`, https://coss.com/docs/mcp.md) gives an agent the same answers as tools, plus a search of these docs.

## Docs

- Get started: What coss.com is, your first email, and the keys every product shares.
  - [Introduction](https://coss.com/docs/index.md): One API key and one SDK for every product.
  - [Quickstart](https://coss.com/docs/quickstart.md): Send your first email with the TypeScript SDK, or the SDK of another language.
  - [Environments and API keys](https://coss.com/docs/environments.md): Organizations, projects, environments, and the keys that belong to them.

  - **Migrating**
  - [Overview](https://coss.com/docs/migrate.md): Import your domains, templates, contacts, suppressions and webhooks from Resend, SendGrid or Postmark.
  - [From Resend](https://coss.com/docs/migrate/resend.md): What an import brings over from Resend, how it maps onto coss.com, and how to switch your code.
  - [From SendGrid](https://coss.com/docs/migrate/sendgrid.md): What an import brings over from SendGrid, how it maps onto coss.com, and how to switch your code.
  - [From Postmark](https://coss.com/docs/migrate/postmark.md): What an import brings over from Postmark, how it maps onto coss.com, and how to switch your code.
- Email: Transactional and marketing email from your own domains, and email you receive.

  - **Sending and receiving**
  - [Sending email](https://coss.com/docs/email/sending.md): Addresses, content, headers, tags, categories and safe retries.
  - [Templates](https://coss.com/docs/email/templates.md): Keep subjects and bodies in coss.com, versioned and localized, and send them with variables.
  - [SMTP](https://coss.com/docs/email/smtp.md): Send through coss.com from anything that speaks SMTP, with an API key as the password.
  - [Receiving email](https://coss.com/docs/email/receiving.md): Receive email at coss.com's inbound address or your own domain, and read it from a webhook or the API.

  - **Deliverability**
  - [Domains](https://coss.com/docs/email/domains.md): Verify a domain to send live email from it.
  - [Transactional and marketing email](https://coss.com/docs/email/streams.md): Two streams, so marketing complaints never hold up password resets.
  - [Suppressions](https://coss.com/docs/email/suppressions.md): Addresses that sends skip, after a bounce, a complaint or an unsubscribe.
  - [DMARC](https://coss.com/docs/email/dmarc.md): Read your domains' DMARC reports and move safely from p=none to p=reject.
  - [Dedicated IPs](https://coss.com/docs/email/dedicated-ips.md): Send live email from your own IPs, warmed up automatically.
  - [Brand logos (BIMI)](https://coss.com/docs/email/bimi.md): Show your logo next to your emails in Gmail, Apple Mail and other inboxes.

  - **Tracking**
  - [Delivery status](https://coss.com/docs/email/delivery.md): How an email and each of its recipients move through delivery.
  - [Open and click tracking](https://coss.com/docs/email/tracking.md): Count opens and clicks, and serve tracking links from your own domain.
  - [Content storage](https://coss.com/docs/email/content-storage.md): Keep no copy of your emails' content once they are sent.

  - **Marketing**
  - [Contacts](https://coss.com/docs/email/contacts.md): The people your marketing email goes to, with custom properties and their consent.
  - [Audiences and segments](https://coss.com/docs/email/audiences-and-segments.md): Static lists of contacts, and filters over them that are always current.
  - [Topics and preferences](https://coss.com/docs/email/topics-and-preferences.md): What contacts subscribe to, the hosted preference center, one-click unsubscribe and double opt-in.
  - [One-click unsubscribe](https://coss.com/docs/email/unsubscribe.md): List-Unsubscribe headers that mailbox providers show as an Unsubscribe button, backed by your suppression list.
  - [Broadcasts](https://coss.com/docs/email/broadcasts.md): One marketing email to an audience or a segment, scheduled, paced and measured.
- SMS: Text messages from your own registered numbers, and the replies they receive.
  - [SMS](https://coss.com/docs/sms.md): Send and receive text messages from your organization's phone numbers.
  - [Sending SMS](https://coss.com/docs/sms/sending.md): Numbers, segments, statuses, scheduling, failures and suppressions.
  - [Numbers and registration](https://coss.com/docs/sms/senders.md): Local and toll-free numbers, US A2P 10DLC registration and toll-free verification.
  - [Receiving SMS](https://coss.com/docs/sms/receiving.md): Replies to your numbers, STOP, START and HELP, and their webhooks.
  - [Testing SMS](https://coss.com/docs/sms/testing.md): Simulate every outcome from a sandbox environment with the SMS simulator.
  - [Countries and pricing](https://coss.com/docs/sms/countries-and-pricing.md): Where live SMS can go, and what messages, numbers and registrations cost.
- Hooks: Webhooks as a service: send each event once, and coss.com delivers it to your customers' endpoints.
  - [Hooks](https://coss.com/docs/hooks.md): Webhooks as a service. Send a message once; coss.com delivers it to every endpoint your customers registered.
  - [Portal](https://coss.com/docs/hooks/portal.md): A ready-made page where your customers manage their webhook endpoints.
  - [Receiving messages](https://coss.com/docs/hooks/receiving.md): What your customers' endpoints receive, and how they verify it. Share this with them.
  - [Delivery, retries and limits](https://coss.com/docs/hooks/delivery.md): How coss.com retries, disables failing endpoints, recovers missed messages, and what it limits.
- Risk: Decide whether a sign-up, login, payment or post looks like abuse, and why.

  - **Assessments**
  - [Risk assessments](https://coss.com/docs/risk.md): Ask coss.com whether a sign-up, login or other event looks like abuse, and why.
  - [Reasons and scores](https://coss.com/docs/risk/reasons.md): Every reason an assessment can give, and how they become a decision.
  - [Rules](https://coss.com/docs/risk/rules.md): Decide specific cases yourself, like "block sign-ups with a disposable email from a data center".
  - [Settings](https://coss.com/docs/risk/settings.md): Thresholds, reasons you don't want, and captcha verification for an environment.

  - **Signals**
  - [Checkouts](https://coss.com/docs/risk/checkout.md): Assess payments with what your payment processor knows about the card.
  - [Devices](https://coss.com/docs/risk/devices.md): Recognize the browser behind sign-ups and logins with coss/device.
  - [Content classification](https://coss.com/docs/risk/content.md): Score what people post (bios, messages, listings) for spam, phishing, malware and fraud.

  - **Building blocks**
  - [Email and IP checks](https://coss.com/docs/risk/lookups.md): Look up an email or IP address on its own, without an assessment.
  - [Rate limiting](https://coss.com/docs/risk/rate-limits.md): Limit your own endpoints per user, email or IP address with buckets you define.

  - **Review and tuning**
  - [Lists, feedback and reviews](https://coss.com/docs/risk/lists-and-feedback.md): Teach coss.com about your users, and work through the review queue.
  - [Calibration](https://coss.com/docs/risk/calibration.md): Learn from your feedback which reasons and rules are right for your traffic.
  - [Testing](https://coss.com/docs/risk/testing.md): Exercise every decision from a sandbox environment.
- Platform: What every product shares: webhooks, logs, the audit log, billing and retention.

  - **Events and logs**
  - [Webhooks](https://coss.com/docs/webhooks.md): Get told when something happens, instead of polling.
  - [Logs](https://coss.com/docs/logs.md): Every API request, email event and webhook attempt of an environment, in one place.
  - [Log drains](https://coss.com/docs/log-drains.md): Stream an environment's logs and audit events to your own logging stack.
  - [Audit log](https://coss.com/docs/audit-log.md): Who changed what in your organization, from the dashboard, the API or coss.com support.

  - **Account**
  - [Plans and billing](https://coss.com/docs/billing.md): How coss.com plans, usage credit, volume pricing and invoices work.
  - [Spend and budgets](https://coss.com/docs/spend.md): See what each project, API key and member costs, and cap it with monthly budgets.
  - [Data retention](https://coss.com/docs/data-retention.md): How long coss.com keeps your emails, delivery history and account data, and what happens after.
- SDKs and tools: The TypeScript SDK, the SDKs of six more languages, framework integrations, the CLI and the MCP server.

  - **TypeScript SDK**
  - [Overview](https://coss.com/docs/sdk.md): Install the coss package, configure the client and handle results.
  - [Errors and retries](https://coss.com/docs/sdk/errors.md): The error object, error types, and automatic retries.
  - [Verifying webhooks](https://coss.com/docs/sdk/webhooks.md): Verify webhook requests with verifyWebhook.

  - **Other languages**
  - [Overview](https://coss.com/docs/sdks.md): The coss.com SDKs for Python, Go, Ruby, PHP, Java and .NET, generated from the API's OpenAPI document.
  - [Python](https://coss.com/docs/sdks/python.md): Install the cosscom package, configure the client, handle errors and verify webhooks in Python.
  - [Go](https://coss.com/docs/sdks/go.md): Install github.com/cosscom/coss-go, configure the client, handle errors and verify webhooks in Go.
  - [Ruby](https://coss.com/docs/sdks/ruby.md): Install the coss gem, configure the client, handle errors and verify webhooks in Ruby.
  - [PHP](https://coss.com/docs/sdks/php.md): Install coss/coss with Composer, configure the client, handle errors and verify webhooks in PHP.
  - [Java](https://coss.com/docs/sdks/java.md): Add com.coss:coss with Gradle or Maven, configure the client, handle errors and verify webhooks in Java.
  - [.NET](https://coss.com/docs/sdks/dotnet.md): Install the Coss NuGet package, configure the client, handle errors and verify webhooks in C#.

  - **Integrations**
  - [Overview](https://coss.com/docs/integrations.md): Send email through coss.com from the libraries you already use, by changing configuration instead of call sites.
  - [Nodemailer](https://coss.com/docs/integrations/nodemailer.md): A Nodemailer transport that sends through coss.com, with attachments, inline images and per-message coss.com settings.
  - [Better Auth](https://coss.com/docs/integrations/better-auth.md): Send Better Auth's verification, password reset, magic link, one-time code and invitation emails through coss.com.
  - [Auth.js](https://coss.com/docs/integrations/authjs.md): An Auth.js (NextAuth.js) email provider that sends magic sign-in links through coss.com.
  - [Laravel](https://coss.com/docs/integrations/laravel.md): A Laravel mail transport that sends Mailables and notifications through coss.com, with categories, tags, scheduling and tracking per message.
  - [Rails](https://coss.com/docs/integrations/rails.md): An Action Mailer delivery method that sends Rails mailers through coss.com, with categories, tags, scheduling and tracking per message.
  - [Django](https://coss.com/docs/integrations/django.md): A Django email backend that sends send_mail, EmailMessage and every other Django email through coss.com, with categories, tags, scheduling and tracking per message.

  - **CLI and agents**
  - [Coding agents](https://coss.com/docs/agents.md): Point Claude Code, Cursor, Codex or any coding agent at coss.com, and it adds email, SMS and webhooks to your project.
  - [CLI](https://coss.com/docs/cli.md): Sign in from your terminal, send test emails and SMS, follow your log, and get webhooks on localhost.
  - [MCP server](https://coss.com/docs/mcp.md): Let your coding agent look up emails, explain why one wasn't delivered, and fix your setup.
- API reference: Every endpoint of the HTTP API, with SDK and HTTP examples you can run.
  - [Overview](https://coss.com/docs/api-reference.md): Base URL, authentication and conventions of the coss.com HTTP API.
  - [Versioning](https://coss.com/docs/api-reference/versioning.md): Dated API versions, the Coss-Version header and your organization's pinned version.
  - [Changelog](https://coss.com/docs/api-reference/changelog.md): Every API version and the breaking changes it introduced.
  - [Errors](https://coss.com/docs/api-reference/errors.md): The error envelope and what each error type means.
  - [Idempotency](https://coss.com/docs/api-reference/idempotency.md): Retry POST requests without sending twice.

  - **Email**
  - Emails: Send transactional email and follow its delivery.
    - [List emails](https://coss.com/docs/api-reference/emails/list-emails.md): GET /v1/emails
    - [Send an email](https://coss.com/docs/api-reference/emails/send-email.md): POST /v1/emails
    - [Send a batch of emails](https://coss.com/docs/api-reference/emails/send-email-batch.md): POST /v1/emails/batch
    - [Retrieve a batch of emails](https://coss.com/docs/api-reference/emails/get-email-batch.md): GET /v1/emails/batch/{id}
    - [Retrieve an email](https://coss.com/docs/api-reference/emails/get-email.md): GET /v1/emails/{id}
    - [Cancel a scheduled email](https://coss.com/docs/api-reference/emails/cancel-email.md): POST /v1/emails/{id}/cancel
    - [Reschedule a scheduled email](https://coss.com/docs/api-reference/emails/reschedule-email.md): POST /v1/emails/{id}/reschedule
    - [List an email's delivery events](https://coss.com/docs/api-reference/emails/list-email-events.md): GET /v1/emails/{id}/events
    - [List an email's tracked links](https://coss.com/docs/api-reference/emails/list-email-links.md): GET /v1/emails/{id}/links
  - Email templates: Versioned, localized subjects and bodies with typed variables, sent by id or alias.
    - [List email templates](https://coss.com/docs/api-reference/email-templates/list-email-templates.md): GET /v1/email_templates
    - [Create an email template](https://coss.com/docs/api-reference/email-templates/create-email-template.md): POST /v1/email_templates
    - [Retrieve an email template](https://coss.com/docs/api-reference/email-templates/get-email-template.md): GET /v1/email_templates/{id}
    - [Update an email template](https://coss.com/docs/api-reference/email-templates/update-email-template.md): PATCH /v1/email_templates/{id}
    - [Delete an email template](https://coss.com/docs/api-reference/email-templates/delete-email-template.md): DELETE /v1/email_templates/{id}
    - [Retrieve a template's draft](https://coss.com/docs/api-reference/email-templates/get-email-template-draft.md): GET /v1/email_templates/{id}/draft
    - [Update a template's draft](https://coss.com/docs/api-reference/email-templates/update-email-template-draft.md): PUT /v1/email_templates/{id}/draft
    - [Publish a template's draft](https://coss.com/docs/api-reference/email-templates/publish-email-template.md): POST /v1/email_templates/{id}/publish
    - [Render a template](https://coss.com/docs/api-reference/email-templates/render-email-template.md): POST /v1/email_templates/{id}/render
    - [List a template's versions](https://coss.com/docs/api-reference/email-templates/list-email-template-versions.md): GET /v1/email_templates/{id}/versions
    - [Retrieve a template version](https://coss.com/docs/api-reference/email-templates/get-email-template-version.md): GET /v1/email_templates/{id}/versions/{version}
    - [Restore a template version](https://coss.com/docs/api-reference/email-templates/restore-email-template-version.md): POST /v1/email_templates/{id}/versions/{version}/restore
  - Domains: The organization's verified sending domains.
    - [List sending domains](https://coss.com/docs/api-reference/domains/list-domains.md): GET /v1/domains
    - [Add a sending domain](https://coss.com/docs/api-reference/domains/create-domain.md): POST /v1/domains
    - [Retrieve a sending domain](https://coss.com/docs/api-reference/domains/get-domain.md): GET /v1/domains/{id}
    - [Remove a sending domain](https://coss.com/docs/api-reference/domains/delete-domain.md): DELETE /v1/domains/{id}
    - [Check a domain's DNS records now](https://coss.com/docs/api-reference/domains/verify-domain.md): POST /v1/domains/{id}/verify
    - [Add a custom tracking domain](https://coss.com/docs/api-reference/domains/create-tracking-domain.md): POST /v1/domains/{id}/tracking
    - [Remove a custom tracking domain](https://coss.com/docs/api-reference/domains/delete-tracking-domain.md): DELETE /v1/domains/{id}/tracking
    - [Receive email at a domain](https://coss.com/docs/api-reference/domains/create-receiving-domain.md): POST /v1/domains/{id}/receiving
    - [Stop receiving email at a domain](https://coss.com/docs/api-reference/domains/delete-receiving-domain.md): DELETE /v1/domains/{id}/receiving
    - [Retrieve a domain's DMARC status](https://coss.com/docs/api-reference/domains/get-domain-dmarc.md): GET /v1/domains/{id}/dmarc
    - [List a domain's DMARC reports](https://coss.com/docs/api-reference/domains/list-domain-dmarc-reports.md): GET /v1/domains/{id}/dmarc/reports
    - [Retrieve a DMARC report](https://coss.com/docs/api-reference/domains/get-domain-dmarc-report.md): GET /v1/domains/{id}/dmarc/reports/{report_id}
  - Dedicated IPs: The organization's own sending IPs, warmed up automatically (an add-on).
    - [Retrieve the organization's dedicated IPs](https://coss.com/docs/api-reference/dedicated-ips/get-dedicated-ip-pool.md): GET /v1/dedicated_ips
  - Suppressions: Addresses that sends skip, added by bounces, complaints or you.
    - [List suppressed addresses](https://coss.com/docs/api-reference/suppressions/list-suppressions.md): GET /v1/suppressions
    - [Add an address to the suppression list](https://coss.com/docs/api-reference/suppressions/create-suppression.md): POST /v1/suppressions
    - [Check whether an address is suppressed](https://coss.com/docs/api-reference/suppressions/check-suppression.md): GET /v1/suppressions/check
    - [Import suppressions in bulk](https://coss.com/docs/api-reference/suppressions/import-suppressions.md): POST /v1/suppressions/import
    - [Export the suppression list as CSV](https://coss.com/docs/api-reference/suppressions/export-suppressions.md): GET /v1/suppressions/export
    - [Retrieve a suppression](https://coss.com/docs/api-reference/suppressions/get-suppression.md): GET /v1/suppressions/{id}
    - [Remove a suppression](https://coss.com/docs/api-reference/suppressions/delete-suppression.md): DELETE /v1/suppressions/{id}
  - Tracking: Which emails of the environment have their opens and clicks tracked.
    - [Retrieve tracking settings](https://coss.com/docs/api-reference/tracking/get-tracking-settings.md): GET /v1/tracking_settings
    - [Update the tracking default](https://coss.com/docs/api-reference/tracking/update-tracking-default.md): PATCH /v1/tracking_settings/default
    - [Remove the tracking default](https://coss.com/docs/api-reference/tracking/delete-tracking-default.md): DELETE /v1/tracking_settings/default
    - [Update a category's tracking rule](https://coss.com/docs/api-reference/tracking/update-tracking-category.md): PATCH /v1/tracking_settings/categories/{category}
    - [Remove a category's tracking rule](https://coss.com/docs/api-reference/tracking/delete-tracking-category.md): DELETE /v1/tracking_settings/categories/{category}
  - Content storage
    - [Retrieve storage settings](https://coss.com/docs/api-reference/content-storage/get-storage-settings.md): GET /v1/storage_settings
    - [Update storage settings](https://coss.com/docs/api-reference/content-storage/update-storage-settings.md): PATCH /v1/storage_settings
  - Reputation: The organization's sending standing (good, warning or suspended) and why.
    - [Retrieve the organization's sending reputation](https://coss.com/docs/api-reference/reputation/get-reputation.md): GET /v1/reputation
  - Receiving: Email received at the environment's inbound address and receiving domains.
    - [List received emails](https://coss.com/docs/api-reference/receiving/list-received-emails.md): GET /v1/received_emails
    - [Retrieve the environment's inbound address](https://coss.com/docs/api-reference/receiving/get-inbound-address.md): GET /v1/received_emails/address
    - [Retrieve a received email](https://coss.com/docs/api-reference/receiving/get-received-email.md): GET /v1/received_emails/{id}
    - [Delete a received email](https://coss.com/docs/api-reference/receiving/delete-received-email.md): DELETE /v1/received_emails/{id}
    - [Download a received email's raw message](https://coss.com/docs/api-reference/receiving/get-received-email-raw.md): GET /v1/received_emails/{id}/raw
    - [Download an attachment of a received email](https://coss.com/docs/api-reference/receiving/get-received-email-attachment.md): GET /v1/received_emails/{id}/attachments/{attachment_id}

  - **Marketing**
  - Contacts: The people marketing email goes to, with their properties and consent.
    - [List contacts](https://coss.com/docs/api-reference/contacts/list-contacts.md): GET /v1/contacts
    - [Create or update a contact](https://coss.com/docs/api-reference/contacts/upsert-contact.md): POST /v1/contacts
    - [Resend a contact's confirmation email](https://coss.com/docs/api-reference/contacts/resend-contact-confirmation.md): POST /v1/contacts/{id}/confirmation
    - [Create a contact's preference links](https://coss.com/docs/api-reference/contacts/create-preference-links.md): POST /v1/contacts/{id}/preference_links
    - [Import contacts in bulk](https://coss.com/docs/api-reference/contacts/import-contacts.md): POST /v1/contacts/import
    - [Export contacts as CSV](https://coss.com/docs/api-reference/contacts/export-contacts.md): GET /v1/contacts/export
    - [Retrieve a contact](https://coss.com/docs/api-reference/contacts/get-contact.md): GET /v1/contacts/{id}
    - [Update a contact](https://coss.com/docs/api-reference/contacts/update-contact.md): PATCH /v1/contacts/{id}
    - [Delete a contact](https://coss.com/docs/api-reference/contacts/delete-contact.md): DELETE /v1/contacts/{id}
    - [Retrieve a contact's topics](https://coss.com/docs/api-reference/contacts/get-contact-topics.md): GET /v1/contacts/{id}/topics
    - [Update a contact's topics](https://coss.com/docs/api-reference/contacts/update-contact-topics.md): PATCH /v1/contacts/{id}/topics
    - [List contact properties](https://coss.com/docs/api-reference/contacts/list-contact-properties.md): GET /v1/contact_properties
    - [Create a contact property](https://coss.com/docs/api-reference/contacts/create-contact-property.md): POST /v1/contact_properties
    - [Retrieve a contact property](https://coss.com/docs/api-reference/contacts/get-contact-property.md): GET /v1/contact_properties/{id}
    - [Update a contact property's fallback](https://coss.com/docs/api-reference/contacts/update-contact-property.md): PATCH /v1/contact_properties/{id}
    - [Delete a contact property](https://coss.com/docs/api-reference/contacts/delete-contact-property.md): DELETE /v1/contact_properties/{id}
  - Audiences: Lists of contacts that broadcasts are sent to.
    - [List audiences](https://coss.com/docs/api-reference/audiences/list-audiences.md): GET /v1/audiences
    - [Create an audience](https://coss.com/docs/api-reference/audiences/create-audience.md): POST /v1/audiences
    - [Retrieve an audience](https://coss.com/docs/api-reference/audiences/get-audience.md): GET /v1/audiences/{id}
    - [Rename an audience](https://coss.com/docs/api-reference/audiences/update-audience.md): PATCH /v1/audiences/{id}
    - [Delete an audience](https://coss.com/docs/api-reference/audiences/delete-audience.md): DELETE /v1/audiences/{id}
    - [List an audience's contacts](https://coss.com/docs/api-reference/audiences/list-audience-contacts.md): GET /v1/audiences/{id}/contacts
    - [Add contacts to an audience](https://coss.com/docs/api-reference/audiences/add-audience-contacts.md): POST /v1/audiences/{id}/contacts
    - [Remove a contact from an audience](https://coss.com/docs/api-reference/audiences/remove-audience-contact.md): DELETE /v1/audiences/{id}/contacts/{contact_id}
  - Segments: Contacts chosen by their properties, always up to date.
    - [List segments](https://coss.com/docs/api-reference/segments/list-segments.md): GET /v1/segments
    - [Create a segment](https://coss.com/docs/api-reference/segments/create-segment.md): POST /v1/segments
    - [Retrieve a segment](https://coss.com/docs/api-reference/segments/get-segment.md): GET /v1/segments/{id}
    - [Update a segment](https://coss.com/docs/api-reference/segments/update-segment.md): PATCH /v1/segments/{id}
    - [Delete a segment](https://coss.com/docs/api-reference/segments/delete-segment.md): DELETE /v1/segments/{id}
    - [List a segment's contacts](https://coss.com/docs/api-reference/segments/list-segment-contacts.md): GET /v1/segments/{id}/contacts
  - Topics: What contacts subscribe to, and the environment's marketing settings.
    - [List topics](https://coss.com/docs/api-reference/topics/list-topics.md): GET /v1/topics
    - [Create a topic](https://coss.com/docs/api-reference/topics/create-topic.md): POST /v1/topics
    - [Retrieve a topic](https://coss.com/docs/api-reference/topics/get-topic.md): GET /v1/topics/{id}
    - [Update a topic](https://coss.com/docs/api-reference/topics/update-topic.md): PATCH /v1/topics/{id}
    - [Delete a topic](https://coss.com/docs/api-reference/topics/delete-topic.md): DELETE /v1/topics/{id}
    - [Retrieve the marketing settings](https://coss.com/docs/api-reference/topics/get-marketing-settings.md): GET /v1/marketing_settings
    - [Update the marketing settings](https://coss.com/docs/api-reference/topics/update-marketing-settings.md): PATCH /v1/marketing_settings
  - Broadcasts: Marketing email sent to an audience or segment.
    - [List broadcasts](https://coss.com/docs/api-reference/broadcasts/list-broadcasts.md): GET /v1/broadcasts
    - [Create a broadcast](https://coss.com/docs/api-reference/broadcasts/create-broadcast.md): POST /v1/broadcasts
    - [Retrieve a broadcast](https://coss.com/docs/api-reference/broadcasts/get-broadcast.md): GET /v1/broadcasts/{id}
    - [Update a draft broadcast](https://coss.com/docs/api-reference/broadcasts/update-broadcast.md): PATCH /v1/broadcasts/{id}
    - [Delete a broadcast](https://coss.com/docs/api-reference/broadcasts/delete-broadcast.md): DELETE /v1/broadcasts/{id}
    - [Send a broadcast](https://coss.com/docs/api-reference/broadcasts/send-broadcast.md): POST /v1/broadcasts/{id}/send
    - [Cancel a broadcast](https://coss.com/docs/api-reference/broadcasts/cancel-broadcast.md): POST /v1/broadcasts/{id}/cancel
    - [Pause a broadcast](https://coss.com/docs/api-reference/broadcasts/pause-broadcast.md): POST /v1/broadcasts/{id}/pause
    - [Resume a broadcast](https://coss.com/docs/api-reference/broadcasts/resume-broadcast.md): POST /v1/broadcasts/{id}/resume
    - [Send a test of a broadcast](https://coss.com/docs/api-reference/broadcasts/test-broadcast.md): POST /v1/broadcasts/{id}/test
    - [List a broadcast's emails](https://coss.com/docs/api-reference/broadcasts/list-broadcast-emails.md): GET /v1/broadcasts/{id}/emails

  - **SMS**
  - SMS: Send text messages from the organization's numbers, follow their delivery, and read replies and opt-outs.
    - [List SMS](https://coss.com/docs/api-reference/sms/list-sms.md): GET /v1/sms
    - [Send an SMS](https://coss.com/docs/api-reference/sms/send-sms.md): POST /v1/sms
    - [List suppressed numbers](https://coss.com/docs/api-reference/sms/list-sms-suppressions.md): GET /v1/sms/suppressions
    - [Add a number to the SMS suppression list](https://coss.com/docs/api-reference/sms/create-sms-suppression.md): POST /v1/sms/suppressions
    - [Check whether a number is suppressed](https://coss.com/docs/api-reference/sms/check-sms-suppression.md): GET /v1/sms/suppressions/check
    - [Retrieve an SMS suppression](https://coss.com/docs/api-reference/sms/get-sms-suppression.md): GET /v1/sms/suppressions/{id}
    - [Remove a number from the SMS suppression list](https://coss.com/docs/api-reference/sms/delete-sms-suppression.md): DELETE /v1/sms/suppressions/{id}
    - [List received SMS](https://coss.com/docs/api-reference/sms/list-received-sms.md): GET /v1/sms/received
    - [Retrieve a received SMS](https://coss.com/docs/api-reference/sms/get-received-sms.md): GET /v1/sms/received/{id}
    - [List the organization's phone numbers](https://coss.com/docs/api-reference/sms/list-sms-numbers.md): GET /v1/sms/numbers
    - [Retrieve an SMS](https://coss.com/docs/api-reference/sms/get-sms.md): GET /v1/sms/{id}
    - [List an SMS's events](https://coss.com/docs/api-reference/sms/list-sms-events.md): GET /v1/sms/{id}/events
    - [Cancel a scheduled SMS](https://coss.com/docs/api-reference/sms/cancel-sms.md): POST /v1/sms/{id}/cancel

  - **Hooks**
  - Hooks applications: Hooks (webhooks as a service): your customers, each with their own endpoints and portal.
    - [List applications](https://coss.com/docs/api-reference/hooks-applications/list-hook-applications.md): GET /v1/hooks/applications
    - [Create an application](https://coss.com/docs/api-reference/hooks-applications/create-hook-application.md): POST /v1/hooks/applications
    - [Retrieve an application](https://coss.com/docs/api-reference/hooks-applications/get-hook-application.md): GET /v1/hooks/applications/{application}
    - [Update an application](https://coss.com/docs/api-reference/hooks-applications/update-hook-application.md): PATCH /v1/hooks/applications/{application}
    - [Delete an application](https://coss.com/docs/api-reference/hooks-applications/delete-hook-application.md): DELETE /v1/hooks/applications/{application}
  - Hooks event types: The catalog of messages you send, which your customers subscribe from.
    - [List event types](https://coss.com/docs/api-reference/hooks-event-types/list-hook-event-types.md): GET /v1/hooks/event_types
    - [Create an event type](https://coss.com/docs/api-reference/hooks-event-types/create-hook-event-type.md): POST /v1/hooks/event_types
    - [Retrieve an event type](https://coss.com/docs/api-reference/hooks-event-types/get-hook-event-type.md): GET /v1/hooks/event_types/{name}
    - [Update an event type](https://coss.com/docs/api-reference/hooks-event-types/update-hook-event-type.md): PATCH /v1/hooks/event_types/{name}
    - [Archive an event type](https://coss.com/docs/api-reference/hooks-event-types/archive-hook-event-type.md): DELETE /v1/hooks/event_types/{name}
  - Hooks endpoints: Your customers' URLs that receive their messages, each signed with its own secret.
    - [List endpoints](https://coss.com/docs/api-reference/hooks-endpoints/list-hook-endpoints.md): GET /v1/hooks/applications/{application}/endpoints
    - [Create an endpoint](https://coss.com/docs/api-reference/hooks-endpoints/create-hook-endpoint.md): POST /v1/hooks/applications/{application}/endpoints
    - [Retrieve an endpoint](https://coss.com/docs/api-reference/hooks-endpoints/get-hook-endpoint.md): GET /v1/hooks/applications/{application}/endpoints/{endpoint_id}
    - [Update an endpoint](https://coss.com/docs/api-reference/hooks-endpoints/update-hook-endpoint.md): PATCH /v1/hooks/applications/{application}/endpoints/{endpoint_id}
    - [Delete an endpoint](https://coss.com/docs/api-reference/hooks-endpoints/delete-hook-endpoint.md): DELETE /v1/hooks/applications/{application}/endpoints/{endpoint_id}
    - [Retrieve an endpoint's secret](https://coss.com/docs/api-reference/hooks-endpoints/get-hook-endpoint-secret.md): GET /v1/hooks/applications/{application}/endpoints/{endpoint_id}/secret
    - [Roll an endpoint's secret](https://coss.com/docs/api-reference/hooks-endpoints/roll-hook-endpoint-secret.md): POST /v1/hooks/applications/{application}/endpoints/{endpoint_id}/roll_secret
    - [Recover failed deliveries](https://coss.com/docs/api-reference/hooks-endpoints/recover-hook-endpoint.md): POST /v1/hooks/applications/{application}/endpoints/{endpoint_id}/recover
    - [Retrieve a recovery](https://coss.com/docs/api-reference/hooks-endpoints/get-hook-endpoint-recovery.md): GET /v1/hooks/applications/{application}/endpoints/{endpoint_id}/recoveries/{recovery_id}
    - [Send a test message](https://coss.com/docs/api-reference/hooks-endpoints/send-hook-endpoint-test.md): POST /v1/hooks/applications/{application}/endpoints/{endpoint_id}/test
    - [List an endpoint's deliveries](https://coss.com/docs/api-reference/hooks-endpoints/list-hook-endpoint-deliveries.md): GET /v1/hooks/applications/{application}/endpoints/{endpoint_id}/deliveries
  - Hooks messages: Send a message once; coss.com delivers it to every subscribed endpoint, with retries.
    - [List messages](https://coss.com/docs/api-reference/hooks-messages/list-hook-messages.md): GET /v1/hooks/applications/{application}/messages
    - [Send a message](https://coss.com/docs/api-reference/hooks-messages/send-hook-message.md): POST /v1/hooks/applications/{application}/messages
    - [Retrieve a message](https://coss.com/docs/api-reference/hooks-messages/get-hook-message.md): GET /v1/hooks/applications/{application}/messages/{message_id}
    - [List a message's deliveries](https://coss.com/docs/api-reference/hooks-messages/list-hook-message-deliveries.md): GET /v1/hooks/applications/{application}/messages/{message_id}/deliveries
    - [Retrieve a delivery](https://coss.com/docs/api-reference/hooks-messages/get-hook-delivery.md): GET /v1/hooks/applications/{application}/deliveries/{delivery_id}
    - [List a delivery's attempts](https://coss.com/docs/api-reference/hooks-messages/list-hook-delivery-attempts.md): GET /v1/hooks/applications/{application}/deliveries/{delivery_id}/attempts
    - [Retry a delivery](https://coss.com/docs/api-reference/hooks-messages/retry-hook-delivery.md): POST /v1/hooks/applications/{application}/deliveries/{delivery_id}/retry
  - Hooks portal: A ready-made page for your customers to manage their endpoints.
    - [Create a portal session](https://coss.com/docs/api-reference/hooks-portal/create-hook-portal-session.md): POST /v1/hooks/applications/{application}/portal_sessions

  - **Risk**
  - Risk: Assess sign-ups, logins and other events: a decision with reasons, from signals and what the environment remembers.
    - [List assessments](https://coss.com/docs/api-reference/risk/list-risk-assessments.md): GET /v1/risk/assessments
    - [Assess an event](https://coss.com/docs/api-reference/risk/create-risk-assessment.md): POST /v1/risk/assessments
    - [Retrieve an assessment](https://coss.com/docs/api-reference/risk/get-risk-assessment.md): GET /v1/risk/assessments/{id}
    - [Report an assessment's outcome](https://coss.com/docs/api-reference/risk/create-risk-feedback.md): POST /v1/risk/assessments/{id}/feedback
    - [List allow and block list entries](https://coss.com/docs/api-reference/risk/list-risk-list-entries.md): GET /v1/risk/list_entries
    - [Add an allow or block list entry](https://coss.com/docs/api-reference/risk/create-risk-list-entry.md): POST /v1/risk/list_entries
    - [Retrieve a list entry](https://coss.com/docs/api-reference/risk/get-risk-list-entry.md): GET /v1/risk/list_entries/{id}
    - [Remove a list entry](https://coss.com/docs/api-reference/risk/delete-risk-list-entry.md): DELETE /v1/risk/list_entries/{id}
    - [Forget a user](https://coss.com/docs/api-reference/risk/forget-risk-user.md): DELETE /v1/risk/users/{user_id}
    - [Retrieve the risk settings](https://coss.com/docs/api-reference/risk/get-risk-settings.md): GET /v1/risk/settings
    - [Update the risk settings](https://coss.com/docs/api-reference/risk/update-risk-settings.md): PATCH /v1/risk/settings
    - [Retrieve the calibration](https://coss.com/docs/api-reference/risk/get-risk-calibration.md): GET /v1/risk/calibration
    - [List rules](https://coss.com/docs/api-reference/risk/list-risk-rules.md): GET /v1/risk/rules
    - [Create a rule](https://coss.com/docs/api-reference/risk/create-risk-rule.md): POST /v1/risk/rules
    - [Retrieve a rule](https://coss.com/docs/api-reference/risk/get-risk-rule.md): GET /v1/risk/rules/{id}
    - [Update a rule](https://coss.com/docs/api-reference/risk/update-risk-rule.md): PATCH /v1/risk/rules/{id}
    - [Delete a rule](https://coss.com/docs/api-reference/risk/delete-risk-rule.md): DELETE /v1/risk/rules/{id}
    - [Check an email address](https://coss.com/docs/api-reference/risk/check-risk-email.md): POST /v1/risk/email/check
    - [Check an IP address](https://coss.com/docs/api-reference/risk/check-risk-ip.md): POST /v1/risk/ip/check
    - [Classify content](https://coss.com/docs/api-reference/risk/classify-risk-content.md): POST /v1/risk/content/classify
    - [Check a rate limit](https://coss.com/docs/api-reference/risk/check-risk-limit.md): POST /v1/risk/limits
    - [List rate limit buckets](https://coss.com/docs/api-reference/risk/list-risk-limit-buckets.md): GET /v1/risk/limit_buckets
    - [Create a rate limit bucket](https://coss.com/docs/api-reference/risk/create-risk-limit-bucket.md): POST /v1/risk/limit_buckets
    - [Retrieve a rate limit bucket](https://coss.com/docs/api-reference/risk/get-risk-limit-bucket.md): GET /v1/risk/limit_buckets/{id}
    - [Update a rate limit bucket](https://coss.com/docs/api-reference/risk/update-risk-limit-bucket.md): PATCH /v1/risk/limit_buckets/{id}
    - [Delete a rate limit bucket](https://coss.com/docs/api-reference/risk/delete-risk-limit-bucket.md): DELETE /v1/risk/limit_buckets/{id}

  - **Platform**
  - Environment: The environment, project and organization an API key belongs to.
    - [Retrieve the API key's environment](https://coss.com/docs/api-reference/environment/get-environment.md): GET /v1/environment
    - [Revoke the API key](https://coss.com/docs/api-reference/environment/revoke-api-key.md): DELETE /v1/api_key
  - Webhook endpoints: URLs that receive the environment's delivery events, signed.
    - [List webhook endpoints](https://coss.com/docs/api-reference/webhook-endpoints/list-webhook-endpoints.md): GET /v1/webhook_endpoints
    - [Create a webhook endpoint](https://coss.com/docs/api-reference/webhook-endpoints/create-webhook-endpoint.md): POST /v1/webhook_endpoints
    - [Retrieve a webhook endpoint](https://coss.com/docs/api-reference/webhook-endpoints/get-webhook-endpoint.md): GET /v1/webhook_endpoints/{id}
    - [Update a webhook endpoint](https://coss.com/docs/api-reference/webhook-endpoints/update-webhook-endpoint.md): PATCH /v1/webhook_endpoints/{id}
    - [Delete a webhook endpoint](https://coss.com/docs/api-reference/webhook-endpoints/delete-webhook-endpoint.md): DELETE /v1/webhook_endpoints/{id}
    - [Roll a signing secret](https://coss.com/docs/api-reference/webhook-endpoints/roll-webhook-endpoint-secret.md): POST /v1/webhook_endpoints/{id}/roll_secret
    - [Recover failed deliveries](https://coss.com/docs/api-reference/webhook-endpoints/recover-webhook-endpoint.md): POST /v1/webhook_endpoints/{id}/recover
    - [List an endpoint's deliveries](https://coss.com/docs/api-reference/webhook-endpoints/list-webhook-deliveries.md): GET /v1/webhook_endpoints/{id}/deliveries
    - [Retrieve a delivery](https://coss.com/docs/api-reference/webhook-endpoints/get-webhook-delivery.md): GET /v1/webhook_endpoints/{id}/deliveries/{delivery_id}
    - [Retry a delivery](https://coss.com/docs/api-reference/webhook-endpoints/retry-webhook-delivery.md): POST /v1/webhook_endpoints/{id}/deliveries/{delivery_id}/retry
    - [Open a webhook listener](https://coss.com/docs/api-reference/webhook-endpoints/create-webhook-listener.md): POST /v1/webhook_listeners
    - [Poll a webhook listener](https://coss.com/docs/api-reference/webhook-endpoints/poll-webhook-listener.md): POST /v1/webhook_listeners/{id}/poll
    - [Close a webhook listener](https://coss.com/docs/api-reference/webhook-endpoints/delete-webhook-listener.md): DELETE /v1/webhook_listeners/{id}
    - [Send a test event](https://coss.com/docs/api-reference/webhook-endpoints/create-test-webhook-event.md): POST /v1/webhook_events/test
  - Logs: The environment's API requests, email events and webhook attempts.
    - [List log lines](https://coss.com/docs/api-reference/logs/list-logs.md): GET /v1/logs
    - [Retrieve a log line](https://coss.com/docs/api-reference/logs/get-log.md): GET /v1/logs/{id}
  - Log drains: Endpoints of yours that receive the environment's logs as signed batches.
    - [List log drains](https://coss.com/docs/api-reference/log-drains/list-log-drains.md): GET /v1/log_drains
    - [Create a log drain](https://coss.com/docs/api-reference/log-drains/create-log-drain.md): POST /v1/log_drains
    - [Retrieve a log drain](https://coss.com/docs/api-reference/log-drains/get-log-drain.md): GET /v1/log_drains/{id}
    - [Update a log drain](https://coss.com/docs/api-reference/log-drains/update-log-drain.md): PATCH /v1/log_drains/{id}
    - [Delete a log drain](https://coss.com/docs/api-reference/log-drains/delete-log-drain.md): DELETE /v1/log_drains/{id}
    - [List a drain's batches](https://coss.com/docs/api-reference/log-drains/list-log-drain-batches.md): GET /v1/log_drains/{id}/batches
    - [Retrieve a batch](https://coss.com/docs/api-reference/log-drains/get-log-drain-batch.md): GET /v1/log_drains/{id}/batches/{batch_id}
  - Audit log: Changes to the organization, by members, API keys and coss.com support.
    - [List audit events](https://coss.com/docs/api-reference/audit-log/list-audit-events.md): GET /v1/audit_events
    - [Retrieve an audit event](https://coss.com/docs/api-reference/audit-log/get-audit-event.md): GET /v1/audit_events/{id}
  - Billing: The organization's plan, usage, invoices and credits.
    - [Retrieve the organization's billing](https://coss.com/docs/api-reference/billing/get-billing.md): GET /v1/billing
    - [List usage](https://coss.com/docs/api-reference/billing/list-billing-usage.md): GET /v1/billing/usage
    - [List invoices](https://coss.com/docs/api-reference/billing/list-invoices.md): GET /v1/billing/invoices
    - [Retrieve an invoice](https://coss.com/docs/api-reference/billing/get-invoice.md): GET /v1/billing/invoices/{id}
    - [List credits](https://coss.com/docs/api-reference/billing/list-credits.md): GET /v1/billing/credits