Redirects - Smeldr

Smeldr treats redirects as first-class content. There are two layers: compile-time rules you declare in code, and a runtime table an agent or operator manages live over MCP while the server runs — no redeploy required for either.

Layer 1 — compile-time rules

Use app.Redirect for individual rules you know at build time:

app.Redirect("/old-path", "/new-path", smeldr.Permanent) // 301 Moved Permanently
app.Redirect("/removed",  "",          smeldr.Gone)      // 410 Gone

smeldr.Permanent vs smeldr.Gone

Code	Constant	When to use
301	`smeldr.Permanent`	URL has moved permanently; search engines should follow and update
410	`smeldr.Gone`	Content is intentionally removed; 410 de-indexes faster than 404

Module prefix rewrite

When you rename a module's entire URL prefix, use the smeldr.Redirects option inside app.Content. A single rule covers every URL under the old prefix:

app.Content(&BlogPost{},
    smeldr.At("/articles"),
    smeldr.Redirects(smeldr.From("/posts"), "/articles"),
)

/posts/hello → 301 → /articles/hello.

Layer 2 — runtime management

Activate database-backed redirects with one call:

if err := app.Redirects(db); err != nil {
    log.Fatal(err)
}

app.Redirects(db) does three things:

1. Creates the smeldr_redirects table if it does not exist. 2. Loads any saved rules into the in-memory store immediately. 3. Enables three MCP redirect tools (Editor role required).

MCP tools

Tool	Required params	Optional params	What it does
`create_redirect`	`from` (path)	`to`, `code` (301/302/410), `is_prefix`	Create or update a rule; takes effect immediately
`list_redirects`	—	—	List all rules (compile-time and database)
`delete_redirect`	`from` (path)	—	Remove a rule; takes effect immediately

create_redirect defaults to code: 301. Set code: 410 and omit to for a Gone rule. Set is_prefix: true to match any path that starts with from.

CLI equivalents

smeldr-cli redirect list
smeldr-cli redirect create --from /pricing --to /plans
smeldr-cli redirect create --from /sale --to /offers --code 302
smeldr-cli redirect create --from /old-blog --code 410
smeldr-cli redirect create --from /posts --to /articles --prefix
smeldr-cli redirect delete /pricing

Behaviour guarantees

Chain collapse

Adding A → B and then B → C automatically rewrites the stored A → B into A → C. Every visitor gets a single redirect hop. The maximum collapse depth is 10. Gone destinations are terminal — chains never collapse through a 410.

Longest-match-first for prefix rules

Prefix rules are scanned from most-specific to least-specific.

Zero overhead on real routes

The redirect store is a fallback handler at /. It is only reached when a request matches no other registered route.

Redirect manifest

GET /.well-known/redirects.json exposes the full rule set as JSON. Optionally restrict it:

app.RedirectManifestAuth(smeldr.BearerHMAC(secret, smeldr.Editor))