systemprompt_api/routes/gateway/
models.rs

1//! `/v1/models` catalog endpoint filtered by inference-protocol surface.
2//!
3//! Copyright (c) systemprompt.io — Business Source License 1.1.
4//! See <https://systemprompt.io> for licensing details.
5
6use axum::Json;
7use axum::http::{HeaderMap, StatusCode};
8use serde::Serialize;
9use std::collections::BTreeMap;
10use systemprompt_config::ProfileBootstrap;
11use systemprompt_identifiers::headers::INFERENCE_PROTOCOL;
12use systemprompt_models::profile::{ApiSurface, ProviderRegistry};
13
14#[derive(Debug, Serialize)]
15pub struct RootResponse {
16    pub service: &'static str,
17    pub version: &'static str,
18    pub endpoints: Vec<&'static str>,
19}
20
21pub async fn root() -> Json<RootResponse> {
22    Json(RootResponse {
23        service: "systemprompt-gateway",
24        version: env!("CARGO_PKG_VERSION"),
25        endpoints: vec!["/v1/models", "/v1/messages"],
26    })
27}
28
29#[derive(Debug, Serialize)]
30pub struct ModelEntry {
31    #[serde(rename = "type")]
32    pub kind: &'static str,
33    pub id: String,
34    pub display_name: String,
35    pub created_at: String,
36}
37
38#[derive(Debug, Serialize)]
39pub struct ModelsResponse {
40    pub data: Vec<ModelEntry>,
41    pub has_more: bool,
42    #[serde(skip_serializing_if = "Option::is_none")]
43    pub first_id: Option<String>,
44    #[serde(skip_serializing_if = "Option::is_none")]
45    pub last_id: Option<String>,
46}
47
48pub async fn list(headers: HeaderMap) -> Result<Json<ModelsResponse>, (StatusCode, String)> {
49    let profile = ProfileBootstrap::get().map_err(|e| {
50        (
51            StatusCode::SERVICE_UNAVAILABLE,
52            format!("Profile not ready: {e}"),
53        )
54    })?;
55
56    profile
57        .gateway
58        .as_ref()
59        .and_then(systemprompt_models::profile::GatewayState::resolved)
60        .filter(|g| g.enabled)
61        .ok_or_else(|| (StatusCode::NOT_FOUND, "Gateway not enabled".to_owned()))?;
62
63    let surfaces = surfaces_from_header(&headers)?;
64    let entries = model_entries(&profile.providers, &surfaces);
65    let first_id = entries.first().map(|e| e.id.clone());
66    let last_id = entries.last().map(|e| e.id.clone());
67
68    Ok(Json(ModelsResponse {
69        data: entries,
70        has_more: false,
71        first_id,
72        last_id,
73    }))
74}
75
76/// Resolve the `x-inference-protocol` selection header into API surfaces.
77///
78/// An absent or empty header yields the full catalog (empty slice); an
79/// unrecognised tag, or `backend` (never a client surface), is a
80/// misconfiguration and fails with `400` rather than silently widening or
81/// leaking the advertised set.
82pub fn surfaces_from_header(headers: &HeaderMap) -> Result<Vec<ApiSurface>, (StatusCode, String)> {
83    let Some(raw) = headers
84        .get(INFERENCE_PROTOCOL)
85        .and_then(|v| v.to_str().ok())
86    else {
87        return Ok(Vec::new());
88    };
89    let mut surfaces = Vec::new();
90    for tag in raw.split(',').map(str::trim).filter(|t| !t.is_empty()) {
91        let surface = ApiSurface::from_tag(tag)
92            .filter(|s| *s != ApiSurface::Backend)
93            .ok_or_else(|| {
94                (
95                    StatusCode::BAD_REQUEST,
96                    format!("unknown {INFERENCE_PROTOCOL} value: {tag}"),
97                )
98            })?;
99        surfaces.push(surface);
100    }
101    Ok(surfaces)
102}
103
104pub fn model_entries(registry: &ProviderRegistry, surfaces: &[ApiSurface]) -> Vec<ModelEntry> {
105    let mut by_id: BTreeMap<String, ModelEntry> = BTreeMap::new();
106    for id in registry.advertised_model_ids(surfaces) {
107        by_id.insert(
108            id.clone(),
109            ModelEntry {
110                kind: "model",
111                display_name: humanize_model_id(&id),
112                id,
113                created_at: "1970-01-01T00:00:00Z".to_owned(),
114            },
115        );
116    }
117    by_id.into_values().collect()
118}
119
120pub fn humanize_model_id(id: &str) -> String {
121    id.split('-')
122        .map(|part| {
123            let mut chars = part.chars();
124            chars.next().map_or_else(String::new, |c| {
125                c.to_ascii_uppercase().to_string() + chars.as_str()
126            })
127        })
128        .collect::<Vec<_>>()
129        .join(" ")
130}
systemprompt_api/routes/gateway/models.rs

systemprompt_api/routes/gateway/
models.rs
