Java and Spring Boot

# application.properties
agentdb.url=${AGENTDB_API_URL:https://app.agentdb.link}
agentdb.workspace=${AGENTDB_WORKSPACE}
agentdb.token=${AGENTDB_TOKEN}

@Configuration
class AgentDbConfig {
    @Bean
    RestClient agentdb(@Value("${agentdb.url}") String url,
                       @Value("${agentdb.workspace}") String workspace,
                       @Value("${agentdb.token}") String token) {
        return RestClient.builder()
            .baseUrl(url + "/v1/workspaces/" + workspace)
            .defaultHeader(HttpHeaders.AUTHORIZATION, "Bearer " + token)
            .defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
            .build();
    }
}

@RestController
@RequestMapping("/api/contacts")
class ContactController {
    private final RestClient agentdb;

    ContactController(RestClient agentdb) { this.agentdb = agentdb; }

    @GetMapping
    Map<String, Object> list(@RequestParam(defaultValue = "") String q) {
        String term = q.strip().length() > 100 ? q.strip().substring(0, 100) : q.strip();
        List<Map<String, Object>> where = term.isEmpty() ? List.of() : List.of(Map.of("field", "name", "op", "contains", "value", term));
        Map<String, Object> query = Map.of(
            "object", "contact",
            "where", Map.of("all", where),
            "sort", List.of(Map.of("field", "name", "order", "asc")),
            "limit", 50);
        JsonNode records = agentdb.post().uri("/query").body(query).retrieve().body(JsonNode.class).path("data").path("records");
        List<Map<String, Object>> contacts = new ArrayList<>();
        for (JsonNode r : records) contacts.add(Map.of("id", r.path("id").asText(), "name", r.path("data").path("name").asText()));
        return Map.of("contacts", contacts);
    }

    @PostMapping
    ResponseEntity<Map<String, Object>> create(@RequestBody Map<String, String> body,
                                               @RequestHeader(value = "X-Submit-Id", required = false) String submitId) {
        String name = body.getOrDefault("name", "").strip();
        if (name.isEmpty() || name.length() > 200) return ResponseEntity.badRequest().body(Map.of("error", "A contact needs a name."));
        String key = "spring." + (submitId != null ? submitId.replaceAll("[^A-Za-z0-9-]", "") : UUID.randomUUID().toString());
        JsonNode rec = agentdb.post().uri("/records").header("Idempotency-Key", key)
            .body(Map.of("object", "contact", "data", Map.of("name", name)))
            .retrieve().body(JsonNode.class).path("data");
        return ResponseEntity.status(201).body(Map.of("contact", Map.of("id", rec.path("id").asText(), "name", name)));
    }

    @ExceptionHandler(HttpClientErrorException.class)
    ResponseEntity<Map<String, Object>> agentdbError(HttpClientErrorException e) {
        if (e.getStatusCode().value() == 409) return ResponseEntity.status(409).body(Map.of("error", "Someone changed it first."));
        if (e.getStatusCode().value() == 400) return ResponseEntity.badRequest().body(Map.of("error", "Check the input."));
        return ResponseEntity.status(502).body(Map.of("error", "The data service is not available."));
    }
}