# Cowliss

> Cowliss is a dev-facing customer data platform with code-defined journeys: send identify and track from your apps, compute segments on write, and run durable per-user journeys that send email and webhooks. Every page is markdown (append `index.md` to its URL); the API contract is /openapi.json.

Billing note: Cowliss uses a prepaid wallet, a monthly free allowance plus fixed-amount Stripe top-ups, with a hard stop at zero credit. There are no plans or tiers.

## Start here

- [Cowliss](/index.md): A dev-facing customer data platform with code-defined journeys. Send identify and track from your apps; Cowliss stores profiles and events, computes segments on write, and runs durable per-user journeys, deployed from your own repo, that send email and webhooks.
- [Quickstart](/quickstart/index.md): Install the SDK, create an organization and an API key, send your first identify and track, and see the profile in the dashboard.
- [Concepts](/concepts/index.md): The mental model, how apps, profiles, events, segments, journeys, and delivery fit together, and what lives in Postgres vs ClickHouse vs Temporal.
- [API conventions](/api-conventions/index.md): The rules every endpoint follows: envelopes, error codes, cursor pagination, prefixed IDs, auth, idempotency, and rate limits.

## Tracking code

- [Tracking code](/tracking/index.md): The two calls that put data into Cowliss: identify and track, from the TypeScript SDK or plain HTTP. The ids each call carries, how retries dedupe, and what happens the moment a write lands.
- [Apps and sources](/tracking/apps/index.md): Register each product you run as an app, send through its api source, and connect Clerk so your auth provider's user lifecycle flows into the same profiles without integration code.
- [Identity](/tracking/identity/index.md): How Cowliss knows who a write is about: identifiers on every call, generated profile ids, and resolution that links as it learns.
- [Backfill and batch](/tracking/backfill/index.md): Import history in one request: historical timestamps, per-item results, quiet writes that never fire journeys at the past, and dedupe that makes re-runs safe.

## Transactional emails

- [Email templates](/emails/index.md): The template contract. One file per template with a zod props schema, a subject computed from the props, a send class, and a React Email component. Typed end to end against the journey that sends it.
- [Sending and delivery](/emails/delivery/index.md): What happens between a journey's send call and an inbox. Sending domains, the gates every send passes, the suppression list, and the delivery log that records each outcome.

## Segments

- [Segments](/segments/index.md): Computed audiences. Flat predicates over traits and event history, recomputed on every write, emitting system.segment_entered/system.segment_exited system events that journeys trigger on.

## Journeys

- [Journeys](/journeys/index.md): Author durable per-user journeys in TypeScript. defineJourney, the capability object, triggers, determinism, restart, and the execution limits.
- [Journey API reference](/journeys/api/index.md): Everything a journey file can call. defineJourney and its config, all eleven capabilities on the api object with their arguments and errors, the shared types, and what is frozen or unavailable inside a journey.
- [Journey composition](/journeys/composition/index.md): Journeys that mark users for each other: the journey, trait, segment, journey chain, reversible marks, time-decaying state, and the loop rule.
- [Testing journeys](/journeys/testing/index.md): Four ways to check a journey before it reaches a real inbox, cow test on a virtual clock, cow dev against development, dry runs against a real user with sends disabled, and the development environment, which captures email instead of sending it.

## Guides & templates

- [For agents — CLI + MCP](/guides/agents/index.md): Full admin parity without the dashboard — the Cowliss CLI, the MCP server, and these docs in machine-readable form.
- [Billing](/guides/billing/index.md): The prepaid wallet model: a monthly free allowance, fixed-amount Stripe top-ups, one weighted spend, and a hard stop at zero credit. No plans, no tiers, no feature gates.
- [Data protection and your responsibilities](/guides/data-protection/index.md): You are the controller, Cowliss is the processor — the three documented defaults that count as your instructions, and the tooling Cowliss gives you to honor data rights.
- [Environments](/guides/environments/index.md): Development and production as a hard partition inside one org. The environment lives on the app, ingestion stamps it on every write, and every admin surface selects one.
- [Keys](/guides/keys/index.md): The two credentials an org issues. API keys ingest and nothing else; deploy keys drive the release lifecycle and nothing else.
- [Projects](/guides/projects/index.md): Your journeys and emails are a project in your own repo. cow init, the layout, cow.json, build, push, deploy per environment, rollback, pull, and the dev loop.
- [Template gallery](/templates/index.md): Annotated example journeys, activity decay, abandoned checkout, winback, cross-app pitch, each a real defineJourney definition you can copy into your own project with one command.
- [abandoned-checkout](/templates/abandoned-checkout/index.md): Abandoned carts, incomplete onboarding checklists, unfinished KYC: any funnel step with a clear completion event and a deadline.
- [activity-decay](/templates/activity-decay/index.md): Any rolling-window state a segment should see: active_30d, at_risk, slipping_away.
- [cross-app-pitch](/templates/cross-app-pitch/index.md): Cross-sell between your own products, portfolio onboarding ("you use app A, try app B"), upgrade prompts timed to a billing event.
- [winback](/templates/winback/index.md): Winback and churn-prevention flows over any recurring signal: purchases, logins, sessions, uploads.

## API reference

- [API reference](/reference/api/index.md): Every endpoint of the /v1 API, generated from the same zod schemas the server validates with — envelopes, examples, and the OpenAPI document.
- [Apps](/reference/api/apps/index.md): The app registry: your apps and products, and the sources that push into them.
- [Artifacts](/reference/api/artifacts/index.md): Content-addressed bundle and source storage: HEAD to check, PUT to upload.
- [Billing](/reference/api/billing/index.md): The prepaid wallet: metered spend against the monthly free allowance, fixed-amount Stripe top-ups, and the hard stop at zero credit.
- [Catalog](/reference/api/catalog/index.md): The tracking plan: event and trait definitions, governance states (allow/deny), and the strict-mode quarantine review queue.
- [Deliveries](/reference/api/deliveries/index.md): The global delivery log (every email and webhook attempted, with status progression) plus the public SES feedback and one-click unsubscribe endpoints.
- [Deployments](/reference/api/deployments/index.md): Which release an environment runs: an append-only log, newest first.
- [Destinations](/reference/api/destinations/index.md): Delivery destinations: webhook URLs (Standard-Webhooks signed) and sender identities, managed in one registry that journeys reference by name.
- [Sending domains](/reference/api/domains/index.md): Org-verified sending domains: claims, DNS records to install, verification status mirrored from SES, and manual re-check.
- [Emails](/reference/api/emails/index.md): The public email-address verification pages: the signed link in a verification email, answered as HTML.
- [Events](/reference/api/events/index.md): The org-wide event feed, per-app volume stats, and single-event fetch: read views over the ClickHouse stream.
- [Executions](/reference/api/executions/index.md): One run of one journey for one profile, pinned to the release it started under.
- [Health](/reference/api/health/index.md): Liveness and readiness probes.
- [Ingestion](/reference/api/ingestion/index.md): POST /v1/identify, /v1/track, and /v1/batch: the org API-key-authenticated write path.
- [Journeys](/reference/api/journeys/index.md): The journeys deployed in an environment: trigger, tags, recorded step spine, the enable switch, and operational stats.
- [Project](/reference/api/project/index.md): The organization's cow project: created by cow init, and what releases belong to.
- [Releases](/reference/api/releases/index.md): One release per cow push: the whole project at one point in time, with its manifest and compile status.
- [Review queue](/reference/api/review/index.md): One list over both halves of the review queue: names held unapplied under a strict policy, and names accepted but flagged under a permissive one.
- [Segments](/reference/api/segments/index.md): Computed audiences: predicate definitions, preview, member lists, and the recomputation lifecycle.
- [Settings](/reference/api/settings/index.md): Org settings: ingestion policy, event retention, the sending-pause state, and self-service org API keys and deploy keys.
- [Sources](/reference/api/sources/index.md): Sources addressed by id: config rotation, archiving, and the public webhook receiver.
- [Suppressions](/reference/api/suppressions/index.md): Cowliss's mirror of the SES account suppression list: the cheap send-gate check and the dashboard's why.
- [Users](/reference/api/users/index.md): Profiles: list, search, the 360 view, consent editing, merged event history, journey timeline, GDPR export and erasure.
- [Violations](/reference/api/violations/index.md): Tracking-plan violations: unknown names accepted but flagged, with one-click resolve into the catalog or dismissal.

## CLI reference

- [CLI reference](/reference/cli/index.md): The Cowliss CLI: login, global flags, JSON output, and every command, generated from the CLI's own command definitions.
- [cow add](/reference/cli/add/index.md): add gallery example code to a cow project
- [cow apps](/reference/cli/apps/index.md): apps
- [cow billing](/reference/cli/billing/index.md): billing
- [cow catalog](/reference/cli/catalog/index.md): catalog
- [Top-level commands](/reference/cli/commands/index.md): cow build, cow deploy, cow dev, cow init, cow login, cow logout, cow pull, cow push, cow rollback, cow test, cow whoami
- [cow deliveries](/reference/cli/deliveries/index.md): deliveries
- [cow deployments](/reference/cli/deployments/index.md): deployments
- [cow destinations](/reference/cli/destinations/index.md): destinations
- [cow domains](/reference/cli/domains/index.md): domains
- [cow events](/reference/cli/events/index.md): events
- [cow executions](/reference/cli/executions/index.md): executions
- [cow journeys](/reference/cli/journeys/index.md): journeys
- [cow project](/reference/cli/project/index.md): project
- [cow releases](/reference/cli/releases/index.md): releases
- [cow review](/reference/cli/review/index.md): review
- [cow segments](/reference/cli/segments/index.md): segments
- [cow settings](/reference/cli/settings/index.md): settings
- [cow sources](/reference/cli/sources/index.md): sources
- [cow suppressions](/reference/cli/suppressions/index.md): suppressions
- [cow users](/reference/cli/users/index.md): users
- [cow violations](/reference/cli/violations/index.md): violations

## Machine-readable contracts

- [OpenAPI 3.1 document](/openapi.json): every endpoint, generated from the zod schemas the server validates with
- [Full docs in one file](/llms-full.txt): the entire site inline