# Computer ports and URLs > Published port rules, mapping syntax, protocols, computer URLs and how each state and lifecycle action affects them > Nevia is in beta and open to selected teams. Public launch in Dec 2026. The CLI installs with `curl -fsSL https://get.nevia.cloud | sh`, and the MCP server is at https://api.nevia.cloud/mcp. A person signs in once in the browser. > Setup, sign-in and requesting access: [SKILL.md](https://nevia.cloud/SKILL.md). When Nevia fits and when it doesn't: [why.md](https://nevia.cloud/why.md). > For the complete documentation index, see [llms.txt](https://nevia.cloud/llms.txt). This page's HTML version: https://nevia.cloud/docs/reference/computer-ports-and-urls This page lists the exact rules for published ports and the computer `url`. To publish a port, see [Publish a computer on an HTTPS URL](https://nevia.cloud/docs/computers/publish.md). For state names, see [Computer lifecycle states](https://nevia.cloud/docs/reference/computer-lifecycle.md). ## Port mappings Each mapping has three fields. | Field | Meaning | Constraint | | ----------- | ------------------------------------------------- | --------------------------------------------------- | | `published` | Port on the platform side. Forms the URL. | `443` or `8000` to `20000`. Unique within the list. | | `target` | Port the workload listens on inside the computer. | `1` to `65535`. | | `protocol` | How the platform speaks to the workload. | `http1` (default) or `http2` (h2c). | * A computer holds at most 16 mappings. * A mapping list replaces as a whole. Send the full list to change one mapping. ### Shorthand syntax The CLI accepts this syntax for `nevia new -p` and `nevia set -p`. Repeat `-p` or separate values with commas. | Input | Published | Target | Protocol | URL | | ------------- | --------- | ------ | -------- | -------------------------------------- | | `8080` | 8080 | 8080 | http1 | `https://:8080` | | `443:8080` | 443 | 8080 | http1 | `https://` | | `8080/h2` | 8080 | 8080 | http2 | `https://:8080` | | `443:3000/h2` | 443 | 3000 | http2 | `https://` | | `none` | n/a | n/a | n/a | Clears all mappings (`nevia set` only) | MCP takes the same fields as objects: `{"published": 443, "target": 3000, "protocol": "http2"}`. `protocol` is optional and defaults to `http1`. ## Protocols | Protocol | Speaks to the workload | Use when | | -------- | --------------------------- | ---------------------------------------------- | | `http1` | HTTP/1.1 | Default. Web servers and most APIs. | | `http2` | HTTP/2 over plaintext (h2c) | The workload speaks only HTTP/2, such as gRPC. | TLS ends at the platform in both cases. Clients always connect to `https://`. The workload never serves TLS. The `/h2` suffix and `http2` set only the protocol to the workload. ## URLs | Rule | Detail | | ----------------- | ------------------------------------------------------------------------------- | | Form | `https://` for `443`. `https://:` for any other port. | | Computer `url` | Set once, when the computer first becomes `ready`. It never changes. | | Per-mapping `url` | Each mapping response includes its own `url`. | | Before a hostname | The mapping `url` is `null` until the computer has a hostname. | | Stability | Sleep and wake keep the `url`. Branch and checkpoint restore issue a new `url`. | | Auth | The URL has no authentication. Anyone with the address can reach it. | `url` shows an address, not the current state. A sleeping computer keeps its `url` but does not answer on it. ## Behaviour by state | State | Computer `url` | Ports | | ---------- | -------------- | ---------------------------------------------------------------------------------- | | `creating` | Not yet set. | Do not answer. | | `ready` | Set. | Answer when the workload listens on the target. Return `503` when nothing listens. | | `sleeping` | Kept. | Do not answer. Changes are refused with `409 invalid_state`. | ## Behaviour by lifecycle action | Action | URL | Ports | Programs | | -------------------- | ---------------------------- | ----------------------------------------------------------- | ------------------------------------------------------- | | Sleep | Kept. | Kept. Do not answer while asleep. | Paused in memory. Active exec sessions end. | | Wake | Kept. | Kept. Answer again. | Resume. Exec sessions do not reconnect. | | Branch | New `url` on a new computer. | Same mapping list. | Not copied. Ports return `503` until something listens. | | Restore a checkpoint | New `url` on a new computer. | Same mapping list. | Not copied. Ports return `503` until something listens. | | Update ports | Kept. | Replaced by the new list. Open connections are interrupted. | Keep running. | Port changes require the `ready` state. A sleeping computer refuses them until you wake it. ## Responses | Condition | Response | | ------------------------------------------------------------------ | -------------------------- | | Workload listens on the target | Forwarded to the workload. | | Nothing listens on the target | `503`. | | Computer sleeping | Port does not answer. | | Port change while sleeping, transitioning or otherwise not `ready` | `409 invalid_state`. | ## Interfaces | Interface | Set ports at create | Change ports later | Notes | | --------- | ---------------------------------- | ----------------------------------- | ----------------------------------------------------------------------------------------------- | | CLI | `nevia new -p ` | `nevia set -p ` | `-p` is repeatable or comma-separated. `none` clears. The CLI publishes nothing by default. | | MCP | `create_computer` with `ports` | `update_computer` with `ports` | `[]` removes HTTPS. Omit `ports` to leave the list unchanged. | | Console | Publishes `443` for new computers. | Toggle, target port and protocol. | Shows one endpoint: the `443` mapping. Mappings on other ports stay in place and do not appear. | Use `nevia status ` to read the computer `url`. See [`nevia new`](https://nevia.cloud/docs/reference/cli/new.md) and [`nevia set`](https://nevia.cloud/docs/reference/cli/set.md) for all flags.