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
48/// Query parameters accepted by [`list`].
49///
50/// Gateway model discovery requests `/v1/models?limit=1000`. An unparseable or
51/// absent value returns the whole catalog rather than failing: discovery has a
52/// three-second budget and treats any non-success as "no models", so a strict
53/// parse would cost the developer their picker entries over a cosmetic input.
54#[derive(Debug, Default, Clone, Copy, serde::Deserialize)]
55pub struct ListQuery {
56    pub limit: Option<usize>,
57}
58
59pub async fn list(
60    headers: HeaderMap,
61    axum::extract::Query(query): axum::extract::Query<ListQuery>,
62) -> Result<Json<ModelsResponse>, (StatusCode, String)> {
63    let profile = ProfileBootstrap::get().map_err(|e| {
64        (
65            StatusCode::SERVICE_UNAVAILABLE,
66            format!("Profile not ready: {e}"),
67        )
68    })?;
69
70    profile
71        .gateway
72        .as_ref()
73        .and_then(systemprompt_models::profile::GatewayState::resolved)
74        .filter(|g| g.enabled)
75        .ok_or_else(|| (StatusCode::NOT_FOUND, "Gateway not enabled".to_owned()))?;
76
77    let surfaces = surfaces_from_header(&headers)?;
78    let mut entries = model_entries(&profile.providers, &surfaces);
79    let total = entries.len();
80    let has_more = match query.limit {
81        Some(limit) if limit < total => {
82            entries.truncate(limit);
83            true
84        },
85        _ => false,
86    };
87    let first_id = entries.first().map(|e| e.id.clone());
88    let last_id = entries.last().map(|e| e.id.clone());
89
90    Ok(Json(ModelsResponse {
91        data: entries,
92        has_more,
93        first_id,
94        last_id,
95    }))
96}
97
98pub fn surfaces_from_header(headers: &HeaderMap) -> Result<Vec<ApiSurface>, (StatusCode, String)> {
99    let Some(raw) = headers
100        .get(INFERENCE_PROTOCOL)
101        .and_then(|v| v.to_str().ok())
102    else {
103        return Ok(Vec::new());
104    };
105    let mut surfaces = Vec::new();
106    for tag in raw.split(',').map(str::trim).filter(|t| !t.is_empty()) {
107        let surface = ApiSurface::from_tag(tag)
108            .filter(|s| *s != ApiSurface::Backend)
109            .ok_or_else(|| {
110                (
111                    StatusCode::BAD_REQUEST,
112                    format!("unknown {INFERENCE_PROTOCOL} value: {tag}"),
113                )
114            })?;
115        surfaces.push(surface);
116    }
117    Ok(surfaces)
118}
119
120pub fn model_entries(registry: &ProviderRegistry, surfaces: &[ApiSurface]) -> Vec<ModelEntry> {
121    let mut by_id: BTreeMap<String, ModelEntry> = BTreeMap::new();
122    for id in registry.advertised_model_ids(surfaces) {
123        by_id.insert(
124            id.clone(),
125            ModelEntry {
126                kind: "model",
127                display_name: humanize_model_id(&id),
128                id,
129                created_at: "1970-01-01T00:00:00Z".to_owned(),
130            },
131        );
132    }
133    by_id.into_values().collect()
134}
135
136pub fn humanize_model_id(id: &str) -> String {
137    id.split('-')
138        .map(|part| {
139            let mut chars = part.chars();
140            chars.next().map_or_else(String::new, |c| {
141                c.to_ascii_uppercase().to_string() + chars.as_str()
142            })
143        })
144        .collect::<Vec<_>>()
145        .join(" ")
146}
systemprompt_api/routes/gateway/models.rs

systemprompt_api/routes/gateway/
models.rs
