diff --git a/build.zig b/build.zig
index 08765bd1df..24a3a88f28 100644
--- a/build.zig
+++ b/build.zig
@@ -11,6 +11,7 @@ const grammar_build = @import("zig/build/grammar.zig");
 const counters_build = @import("zig/build/metal_counters.zig");
 const exl3_build = @import("zig/build/exl3.zig");
 const exlr8_build = @import("zig/build/exlr8.zig");
+const server_build = @import("zig/build/server.zig");
 const golden_build = @import("zig/build/golden.zig");
 
 comptime {
@@ -204,6 +205,7 @@ fn nativeServer(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.b
         .imports = &.{ .{ .name = "engine_api", .module = api }, .{ .name = "tokenizer", .module = tokenizer }, .{ .name = "template", .module = template }, .{ .name = "native_engines", .module = engines }, .{ .name = "checkpoint_cli", .module = b.createModule(.{ .root_source_file = b.path("zig/src/cli/cli.zig"), .target = target, .optimize = .ReleaseSafe, .link_libc = true, .imports = &.{ .{ .name = "native_engines", .module = engines }, exlr8_build.cliImport(b, target, .ReleaseSafe, engine) } }) } },
     }) });
     exe.root_module.addOptions("build_options", build_options);
+    _ = server_build.addTo(b, exe.root_module, target, .ReleaseSafe);
     if (test_step == null) {
         exe.root_module.strip = true;
         return exe;
@@ -221,10 +223,13 @@ fn nativeServer(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.b
         .link_libc = true,
         .imports = &.{ .{ .name = "engine_api", .module = api }, .{ .name = "tokenizer", .module = tokenizer }, .{ .name = "template", .module = template } },
     });
+    const server_json = server_build.addTo(b, server_tests, target, .Debug);
     test_step.?.dependOn(&b.addRunArtifact(b.addTest(.{ .root_module = server_tests })).step);
+    test_step.?.dependOn(&b.addRunArtifact(b.addTest(.{ .root_module = server_json })).step);
     @import("zig/build/cortheon_fuzz.zig").add(b, target, api, tokenizer, template);
     // the parse half's tests, as their own test binary (zig/src/server/tool_parse_test.zig)
     const tool_parse_tests = b.addTest(.{ .root_module = b.createModule(.{ .root_source_file = b.path("zig/src/server/tool_parse_test.zig"), .target = target, .optimize = .Debug, .link_libc = true, .imports = &.{ .{ .name = "engine_api", .module = api }, .{ .name = "tokenizer", .module = tokenizer }, .{ .name = "template", .module = template } } }) });
+    _ = server_build.addTo(b, tool_parse_tests.root_module, target, .Debug);
     test_step.?.dependOn(&b.addRunArtifact(tool_parse_tests).step);
     // the chat-template engine's tests (zig/src/core/template/tests.zig), which no other test binary reaches
     test_step.?.dependOn(&b.addRunArtifact(b.addTest(.{ .root_module = b.createModule(.{ .root_source_file = b.path("zig/src/core/template/tests.zig"), .target = target, .optimize = .Debug, .link_libc = true }) })).step);
diff --git a/zig/build/cortheon_fuzz.zig b/zig/build/cortheon_fuzz.zig
index b17d0e99d0..709bf01f37 100644
--- a/zig/build/cortheon_fuzz.zig
+++ b/zig/build/cortheon_fuzz.zig
@@ -20,6 +20,7 @@ pub fn add(b: *std.Build, target: std.Build.ResolvedTarget, api: *Module, tokeni
         }),
         .filters = &.{"cortheon.fuzz."},
     });
+    _ = @import("server.zig").addTo(b, harness.root_module, target, optimize);
     const step = b.step("fuzz-cortheon", "Cortheon's page, link, search and filter readers under the fuzz harness");
     step.dependOn(&b.addRunArtifact(harness).step);
 }
diff --git a/zig/build/cuda.zig b/zig/build/cuda.zig
index eac681628c..a05e74ccd0 100644
--- a/zig/build/cuda.zig
+++ b/zig/build/cuda.zig
@@ -173,6 +173,7 @@ fn nativeServer(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.b
         .imports = &.{ .{ .name = "engine_api", .module = m.api }, .{ .name = "tokenizer", .module = tokenizer }, .{ .name = "template", .module = template }, .{ .name = "native_engines", .module = m.engines }, .{ .name = "checkpoint_cli", .module = checkpointCli(b, target, .ReleaseSafe, null, m.engines, core) } },
     }) });
     exe.root_module.addOptions("build_options", build_options);
+    _ = @import("server.zig").addTo(b, exe.root_module, target, .ReleaseSafe);
     if (!install_native) {
         exe.root_module.strip = true;
         return exe;
@@ -201,9 +202,14 @@ pub fn hostTests(b: *std.Build, draft_ids: *std.Build.Module, build_options: *st
         .link_libc = true,
         .imports = &.{ .{ .name = "engine_api", .module = native_modules.api }, .{ .name = "tokenizer", .module = mods.tokenizer }, .{ .name = "template", .module = template } },
     });
+    const server_json = @import("server.zig").addTo(b, server_tests, host, .debug);
     const server_test = b.addRunArtifact(b.addTest(.{ .root_module = server_tests }));
-    step.dependOn(&server_test.step);
-    b.step("test-server-cpu", "The HTTP server's unit tests (routes, templates, tool parsing) without a GPU").dependOn(&server_test.step);
+    const json_test = b.addRunArtifact(b.addTest(.{ .root_module = server_json }));
+    const server_step = b.step("test-server-cpu", "The HTTP server's unit tests (routes, templates, tool parsing) without a GPU");
+    for ([_]*std.Build.Step.Run{ server_test, json_test }) |run| {
+        step.dependOn(&run.step);
+        server_step.dependOn(&run.step);
+    }
     // the server goldens and Cortheon's fuzz step here when the target is not macOS, whose Metal build defines them
     if (server_steps) {
         golden_build.step(b, host, server_tests, native_modules.api, mods.tokenizer, template);
diff --git a/zig/build/server.zig b/zig/build/server.zig
new file mode 100644
index 0000000000..54b94bbe16
--- /dev/null
+++ b/zig/build/server.zig
@@ -0,0 +1,14 @@
+//! The server's shared JSON values, available to server and family modules.
+const std = @import("std");
+
+/// The server's JSON values as a module (zig/src/server/json.zig), so a family's serving code shares them.
+pub fn json(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) *std.Build.Module {
+    return b.createModule(.{ .root_source_file = b.path("zig/src/server/json.zig"), .target = target, .optimize = optimize });
+}
+
+/// Attach a server's shared JSON module; its tests run separately from the server's root.
+pub fn addTo(b: *std.Build, m: *std.Build.Module, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) *std.Build.Module {
+    const j = json(b, target, optimize);
+    m.addImport("json", j);
+    return j;
+}
diff --git a/zig/src/server/anthropic.zig b/zig/src/server/anthropic.zig
index bf465e7ac2..c283689367 100644
--- a/zig/src/server/anthropic.zig
+++ b/zig/src/server/anthropic.zig
@@ -1,6 +1,6 @@
 //! Anthropic's Messages routes over the chat handler: typed SSE events, tool_use blocks, count_tokens.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const http_body = @import("http_body.zig");
 const fields = @import("fields.zig");
diff --git a/zig/src/server/anthropic_translate.zig b/zig/src/server/anthropic_translate.zig
index f70b6a112c..095ad66c0a 100644
--- a/zig/src/server/anthropic_translate.zig
+++ b/zig/src/server/anthropic_translate.zig
@@ -1,6 +1,6 @@
 //! Anthropic Messages requests as the chat requests that run them (``anthropic_translate.translate``).
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const fields = @import("fields.zig");
 const pyrepr = @import("pyrepr.zig");
diff --git a/zig/src/server/chat.zig b/zig/src/server/chat.zig
index 7c702ef432..4921b742b0 100644
--- a/zig/src/server/chat.zig
+++ b/zig/src/server/chat.zig
@@ -1,7 +1,7 @@
 //! One reply, as ``ChatApp.chat`` makes it: render, submit to the engine, stream text, reasoning and calls.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const fields_mod = @import("fields.zig");
 const reply_text = @import("reply_text.zig");
diff --git a/zig/src/server/chunk_plan.zig b/zig/src/server/chunk_plan.zig
index 2a4505cdca..9c2ab0e3f3 100644
--- a/zig/src/server/chunk_plan.zig
+++ b/zig/src/server/chunk_plan.zig
@@ -1,6 +1,6 @@
 //! Where a prompt's prefill chunks start (Python's PrefillPlan and message_markers): prompts that agree up to a start cut alike up to it.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const prompt = @import("prompt.zig");
 const Server = @import("server.zig").Server;
diff --git a/zig/src/server/compact.zig b/zig/src/server/compact.zig
index a295aba25b..fce4234e7b 100644
--- a/zig/src/server/compact.zig
+++ b/zig/src/server/compact.zig
@@ -1,6 +1,6 @@
 //! Note and reply are ordinary greedy or keyed generations, so the same request compacts and answers the same way.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const chat = @import("chat.zig");
 const stored = @import("compact_mem.zig");
 const server_mod = @import("server.zig");
diff --git a/zig/src/server/compact_mem.zig b/zig/src/server/compact_mem.zig
index eca242ed0f..b45513bad6 100644
--- a/zig/src/server/compact_mem.zig
+++ b/zig/src/server/compact_mem.zig
@@ -1,6 +1,6 @@
 //! The compaction note file and the hash of the messages a note already covers.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const Server = @import("server.zig").Server;
 const Value = json.Value;
 const Allocator = std.mem.Allocator;
diff --git a/zig/src/server/compact_test.zig b/zig/src/server/compact_test.zig
index b78bf4eff2..986fd10922 100644
--- a/zig/src/server/compact_test.zig
+++ b/zig/src/server/compact_test.zig
@@ -1,7 +1,7 @@
 //! Host checks for opt-in compaction. The fake engine records each prompt and answers OK.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const model_text = @import("model_text.zig");
 const chat = @import("chat.zig");
diff --git a/zig/src/server/completion_prompt_test.zig b/zig/src/server/completion_prompt_test.zig
index ae32cef584..51fc932caf 100644
--- a/zig/src/server/completion_prompt_test.zig
+++ b/zig/src/server/completion_prompt_test.zig
@@ -1,7 +1,7 @@
 //! Token ids in a completion prompt, top-level or nested: ids in the vocabulary are served, other values get a 400.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const model_text = @import("model_text.zig");
 const openai = @import("openai.zig");
 const Server = @import("server.zig").Server;
diff --git a/zig/src/server/cortheon/checks.zig b/zig/src/server/cortheon/checks.zig
index 90a754c665..d6e7b53f76 100644
--- a/zig/src/server/cortheon/checks.zig
+++ b/zig/src/server/cortheon/checks.zig
@@ -1,6 +1,6 @@
 //! Cortheon's checks before a reply ends: changed files tested before "done", researched answers naming sources.
 const std = @import("std");
-const json = @import("../json.zig");
+const json = @import("json");
 const tools = @import("tools.zig");
 const Value = json.Value;
 
diff --git a/zig/src/server/cortheon/cortheon.zig b/zig/src/server/cortheon/cortheon.zig
index fd51addf2d..665c4f5a68 100644
--- a/zig/src/server/cortheon/cortheon.zig
+++ b/zig/src/server/cortheon/cortheon.zig
@@ -1,6 +1,6 @@
 //! Cortheon in the server (--cortheon): its reasoning program, web research before building, server-run web tools.
 const std = @import("std");
-const json = @import("../json.zig");
+const json = @import("json");
 const chat = @import("../chat.zig");
 const grammar = @import("../grammar.zig");
 const prompt_mod = @import("../prompt.zig");
diff --git a/zig/src/server/cortheon/cortheon_test.zig b/zig/src/server/cortheon/cortheon_test.zig
index 019fcf7f1d..2287eaac82 100644
--- a/zig/src/server/cortheon/cortheon_test.zig
+++ b/zig/src/server/cortheon/cortheon_test.zig
@@ -1,7 +1,7 @@
 //! Cortheon end to end on a scripted engine and a stand-in web: rounds, research, streams, splices and checks.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("../json.zig");
+const json = @import("json");
 const model_text = @import("../model_text.zig");
 const openai = @import("../openai.zig");
 const server_mod = @import("../server.zig");
diff --git a/zig/src/server/cortheon/loop.zig b/zig/src/server/cortheon/loop.zig
index 6939e14580..52eb5db2cc 100644
--- a/zig/src/server/cortheon/loop.zig
+++ b/zig/src/server/cortheon/loop.zig
@@ -1,6 +1,6 @@
 //! Cortheon's reply loop: rounds with the model's server tool calls run between them, checks at the end, one reply.
 const std = @import("std");
-const json = @import("../json.zig");
+const json = @import("json");
 const errors = @import("../errors.zig");
 const chat = @import("../chat.zig");
 const tool_parse = @import("../tool_parse.zig");
diff --git a/zig/src/server/cortheon/memory.zig b/zig/src/server/cortheon/memory.zig
index f90a11aa44..b067e8b255 100644
--- a/zig/src/server/cortheon/memory.zig
+++ b/zig/src/server/cortheon/memory.zig
@@ -1,6 +1,6 @@
 //! What a reply's client never saw (server tool rounds, Cortheon notes), kept to splice back in front of it next turn.
 const std = @import("std");
-const json = @import("../json.zig");
+const json = @import("json");
 const Value = json.Value;
 const Allocator = std.mem.Allocator;
 
diff --git a/zig/src/server/cortheon/research.zig b/zig/src/server/cortheon/research.zig
index ef07c1af5e..7483b53e32 100644
--- a/zig/src/server/cortheon/research.zig
+++ b/zig/src/server/cortheon/research.zig
@@ -1,6 +1,6 @@
 //! Research before building: the model names searches, the server runs them and reads the best pages, as hidden rounds.
 const std = @import("std");
-const json = @import("../json.zig");
+const json = @import("json");
 const errors = @import("../errors.zig");
 const chat = @import("../chat.zig");
 const ids = @import("../ids.zig");
diff --git a/zig/src/server/cortheon/search.zig b/zig/src/server/cortheon/search.zig
index 36fadd40cf..590a216f30 100644
--- a/zig/src/server/cortheon/search.zig
+++ b/zig/src/server/cortheon/search.zig
@@ -1,6 +1,6 @@
 //! Web search for Cortheon: DuckDuckGo's keyless HTML results, or Brave's search API when a key is set.
 const std = @import("std");
-const json = @import("../json.zig");
+const json = @import("json");
 const html = @import("html.zig");
 const Allocator = std.mem.Allocator;
 
diff --git a/zig/src/server/cortheon/tools.zig b/zig/src/server/cortheon/tools.zig
index 376706ee19..8901629781 100644
--- a/zig/src/server/cortheon/tools.zig
+++ b/zig/src/server/cortheon/tools.zig
@@ -1,6 +1,6 @@
 //! Cortheon's server-run tools: their specs, which calls are theirs, and each call run into the text the model reads.
 const std = @import("std");
-const json = @import("../json.zig");
+const json = @import("json");
 const search = @import("search.zig");
 const Seen = @import("seen.zig").Seen;
 const Value = json.Value;
diff --git a/zig/src/server/decisions.zig b/zig/src/server/decisions.zig
index b3bd3b64fa..ad87626352 100644
--- a/zig/src/server/decisions.zig
+++ b/zig/src/server/decisions.zig
@@ -1,6 +1,6 @@
 //! /v1/decisions checks a body the way 0.6.6 checks it, then scores through the engine hook when a family sets one.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const fields = @import("fields.zig");
 const pyrepr = @import("pyrepr.zig");
diff --git a/zig/src/server/decisions_test.zig b/zig/src/server/decisions_test.zig
index 160622e9a9..ca3dc87acb 100644
--- a/zig/src/server/decisions_test.zig
+++ b/zig/src/server/decisions_test.zig
@@ -1,7 +1,7 @@
 //! Request checks for /v1/decisions, and a fake engine hook that scores one choice.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const openai = @import("openai.zig");
 const model_text = @import("model_text.zig");
diff --git a/zig/src/server/fields.zig b/zig/src/server/fields.zig
index cd2a9d7340..0ccdc64f18 100644
--- a/zig/src/server/fields.zig
+++ b/zig/src/server/fields.zig
@@ -1,6 +1,6 @@
 //! Request field checks shared by every route: numbers, stops, thinking switches, efforts, probabilities.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const Value = json.Value;
 const Cx = errors.Cx;
diff --git a/zig/src/server/grammar.zig b/zig/src/server/grammar.zig
index c8a68b5c97..543f08a265 100644
--- a/zig/src/server/grammar.zig
+++ b/zig/src/server/grammar.zig
@@ -1,7 +1,7 @@
 //! Structured-output fields checked as ``engine.grammar.request_spec`` checks them; the engine enforces them.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const pyrepr = @import("pyrepr.zig");
 const tool_specs = @import("tool_specs.zig");
diff --git a/zig/src/server/hf_text.zig b/zig/src/server/hf_text.zig
index 65c3a474d5..8a912a29e1 100644
--- a/zig/src/server/hf_text.zig
+++ b/zig/src/server/hf_text.zig
@@ -2,7 +2,7 @@
 const std = @import("std");
 const tokenizer = @import("tokenizer");
 const template = @import("template");
-const json = @import("json.zig");
+const json = @import("json");
 const model_text = @import("model_text.zig");
 const Value = json.Value;
 const Allocator = std.mem.Allocator;
diff --git a/zig/src/server/http_body.zig b/zig/src/server/http_body.zig
index ad2951ebcc..257d11e1be 100644
--- a/zig/src/server/http_body.zig
+++ b/zig/src/server/http_body.zig
@@ -1,6 +1,6 @@
 //! Bounded request bodies, fixed-length or chunked, refused as the Python server refuses them.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const Conn = @import("http_conn.zig").Conn;
 const Allocator = std.mem.Allocator;
diff --git a/zig/src/server/json.zig b/zig/src/server/json.zig
index 2b69a19fc6..c0a035874f 100644
--- a/zig/src/server/json.zig
+++ b/zig/src/server/json.zig
@@ -5,6 +5,7 @@ const Allocator = std.mem.Allocator;
 pub const parse = @import("json_parse.zig").parse;
 pub const parseText = @import("json_parse.zig").parseText;
 pub const ParseResult = @import("json_parse.zig").Result;
+pub const wtf8Encode = @import("json_parse.zig").wtf8Encode;
 pub const write = @import("json_write.zig").write;
 pub const writeString = @import("json_write.zig").writeString;
 pub const Options = @import("json_write.zig").Options;
diff --git a/zig/src/server/live.zig b/zig/src/server/live.zig
index cb0cbaf640..8a1f7df742 100644
--- a/zig/src/server/live.zig
+++ b/zig/src/server/live.zig
@@ -1,7 +1,7 @@
 //! The live status line (connections, decode and prefill tok/s), redrawn in a terminal, and /health's copy of it.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const log = @import("log.zig");
 const Allocator = std.mem.Allocator;
 
diff --git a/zig/src/server/logprobs.zig b/zig/src/server/logprobs.zig
index 669c07f060..549ec9ea15 100644
--- a/zig/src/server/logprobs.zig
+++ b/zig/src/server/logprobs.zig
@@ -1,7 +1,7 @@
 //! OpenAI ``logprobs`` (who may ask, ``choices[0].logprobs`` from the engine's rows) and vLLM's ``prompt_logprobs``.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const reply_text = @import("reply_text.zig");
 const Server = @import("server.zig").Server;
diff --git a/zig/src/server/main.zig b/zig/src/server/main.zig
index 4b85fca8cd..b2e0b971b5 100644
--- a/zig/src/server/main.zig
+++ b/zig/src/server/main.zig
@@ -1,6 +1,6 @@
 //! ``tensorfold-native``: ``capabilities --json`` for the Python switch, and ``serve MODEL [flags]`` with no Python.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const cli = @import("cli.zig");
 const log = @import("log.zig");
 const hub = @import("hub.zig");
diff --git a/zig/src/server/memory_routes.zig b/zig/src/server/memory_routes.zig
index 5a168451b5..a8fa319137 100644
--- a/zig/src/server/memory_routes.zig
+++ b/zig/src/server/memory_routes.zig
@@ -1,7 +1,7 @@
 //! Authenticated, read-only sizing diagnostics; unknown counters and plans are omitted rather than guessed.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const process = @import("process_memory.zig");
 const routes = @import("routes.zig");
 const Server = @import("server.zig").Server;
diff --git a/zig/src/server/messages.zig b/zig/src/server/messages.zig
index 9559ed784b..978eb98aa3 100644
--- a/zig/src/server/messages.zig
+++ b/zig/src/server/messages.zig
@@ -1,6 +1,6 @@
 //! Chat messages as the template sees them: leading instructions merged, text parts joined, call arguments as objects.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const fields = @import("fields.zig");
 const Value = json.Value;
diff --git a/zig/src/server/model_text.zig b/zig/src/server/model_text.zig
index 0b36055a7f..d7b56167ca 100644
--- a/zig/src/server/model_text.zig
+++ b/zig/src/server/model_text.zig
@@ -1,6 +1,6 @@
 //! The tokenizer and chat template a server renders prompts and replies with (the tok and jinja branches plug in here).
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const Allocator = std.mem.Allocator;
 
 pub const RenderOptions = struct {
diff --git a/zig/src/server/openai.zig b/zig/src/server/openai.zig
index b8782aaf96..157ade230b 100644
--- a/zig/src/server/openai.zig
+++ b/zig/src/server/openai.zig
@@ -1,6 +1,6 @@
 //! POST /v1/chat/completions and /v1/completions, JSON or SSE, as ``server.http`` answers them.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const fields = @import("fields.zig");
 const chat = @import("chat.zig");
diff --git a/zig/src/server/prompt.zig b/zig/src/server/prompt.zig
index e68363bfe7..f02c112a39 100644
--- a/zig/src/server/prompt.zig
+++ b/zig/src/server/prompt.zig
@@ -1,6 +1,6 @@
 //! Prompt ids from a request, as ``prepare_prompt`` and ``render_prompt_ids`` make them.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const messages_mod = @import("messages.zig");
 const model_text = @import("model_text.zig");
diff --git a/zig/src/server/pyrepr.zig b/zig/src/server/pyrepr.zig
index d560773580..255232af62 100644
--- a/zig/src/server/pyrepr.zig
+++ b/zig/src/server/pyrepr.zig
@@ -1,6 +1,6 @@
 //! Python's ``repr`` of decoded JSON, for refusal messages that quote a request's value.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const Value = json.Value;
 const Allocator = std.mem.Allocator;
 
diff --git a/zig/src/server/request_log.zig b/zig/src/server/request_log.zig
index ea4c8b7997..7abf7e022e 100644
--- a/zig/src/server/request_log.zig
+++ b/zig/src/server/request_log.zig
@@ -1,6 +1,6 @@
 //! TENSORFOLD_REQUEST_LOG: each chat and completion body appended as one JSON line, images redacted, for replays.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const Value = json.Value;
 const Allocator = std.mem.Allocator;
 
diff --git a/zig/src/server/responses.zig b/zig/src/server/responses.zig
index 2e096025b5..e84a74d0a9 100644
--- a/zig/src/server/responses.zig
+++ b/zig/src/server/responses.zig
@@ -1,6 +1,6 @@
 //! OpenAI's Responses API: each request runs as its chat completion, translated item by item and event by event.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const http_body = @import("http_body.zig");
 const openai = @import("openai.zig");
diff --git a/zig/src/server/responses_include_test.zig b/zig/src/server/responses_include_test.zig
index e117f116b5..3039b8907b 100644
--- a/zig/src/server/responses_include_test.zig
+++ b/zig/src/server/responses_include_test.zig
@@ -1,6 +1,6 @@
 //! Responses' include: OpenAI's values accepted and ignored, anything else refused by name.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const responses_translate = @import("responses_translate.zig");
 
diff --git a/zig/src/server/responses_translate.zig b/zig/src/server/responses_translate.zig
index 8b1b2b17f3..6a5f4c8282 100644
--- a/zig/src/server/responses_translate.zig
+++ b/zig/src/server/responses_translate.zig
@@ -1,6 +1,6 @@
 //! A Responses request as the chat completion that runs it (``responses_translate.translate``).
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const fields = @import("fields.zig");
 const pyrepr = @import("pyrepr.zig");
diff --git a/zig/src/server/root.zig b/zig/src/server/root.zig
index 7630f5217a..29e2fecdde 100644
--- a/zig/src/server/root.zig
+++ b/zig/src/server/root.zig
@@ -1,5 +1,5 @@
 //! The native HTTP server's surface: what main and the test servers build a server from.
-pub const json = @import("json.zig");
+pub const json = @import("json");
 pub const errors = @import("errors.zig");
 pub const auth = @import("auth.zig");
 pub const cli = @import("cli.zig");
@@ -17,7 +17,7 @@ pub const Config = server.Config;
 
 test {
     @import("std").testing.refAllDecls(@This());
-    _ = @import("json.zig");
+    _ = @import("json");
     _ = @import("std_options.zig");
     _ = @import("fields.zig");
     _ = @import("reply_text.zig");
diff --git a/zig/src/server/routes.zig b/zig/src/server/routes.zig
index 44981cdda9..35186a5eca 100644
--- a/zig/src/server/routes.zig
+++ b/zig/src/server/routes.zig
@@ -1,6 +1,6 @@
 //! Method and path dispatch, as ``do_GET``, ``do_POST`` and ``do_DELETE`` route them.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const http_conn = @import("http_conn.zig");
 const http_body = @import("http_body.zig");
 const auth = @import("auth.zig");
diff --git a/zig/src/server/serve.zig b/zig/src/server/serve.zig
index da27cb6b0e..b5e73ed53b 100644
--- a/zig/src/server/serve.zig
+++ b/zig/src/server/serve.zig
@@ -1,7 +1,7 @@
 //! A server's life: keys, the listening socket, the startup lines, the live line, and a clean stop on SIGTERM or SIGINT.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const auth = @import("auth.zig");
 const cli = @import("cli.zig");
 const log = @import("log.zig");
diff --git a/zig/src/server/server.zig b/zig/src/server/server.zig
index 011734ee9a..97ab3e9c0c 100644
--- a/zig/src/server/server.zig
+++ b/zig/src/server/server.zig
@@ -1,7 +1,7 @@
 //! The server: one engine and tokenizer behind the HTTP routes, one thread a connection.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const fields = @import("fields.zig");
 const auth = @import("auth.zig");
diff --git a/zig/src/server/server_init_test.zig b/zig/src/server/server_init_test.zig
index 627d8a7691..0a4872b177 100644
--- a/zig/src/server/server_init_test.zig
+++ b/zig/src/server/server_init_test.zig
@@ -1,7 +1,7 @@
 //! A server init that fails after its idle keepalive started stops that ticker and frees all it took.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const model_text = @import("model_text.zig");
 const server = @import("server.zig");
 const Allocator = std.mem.Allocator;
diff --git a/zig/src/server/slide.zig b/zig/src/server/slide.zig
index 0312840011..c57ddf819f 100644
--- a/zig/src/server/slide.zig
+++ b/zig/src/server/slide.zig
@@ -1,7 +1,7 @@
 //! Sliding Weights over HTTP: /v1/slide/learn streams learning, /v1/slide/graph lists or clears facts, /slide draws.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const sse = @import("sse.zig");
 const http_body = @import("http_body.zig");
 const routes = @import("routes.zig");
diff --git a/zig/src/server/slide_ask.zig b/zig/src/server/slide_ask.zig
index fca6c989ef..57e3c8aa16 100644
--- a/zig/src/server/slide_ask.zig
+++ b/zig/src/server/slide_ask.zig
@@ -1,7 +1,7 @@
 //! What a lesson asks the model and how replies become examples: chat replies, continuations, token ids.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const chat = @import("chat.zig");
 const prompt = @import("prompt.zig");
 const errors = @import("errors.zig");
diff --git a/zig/src/server/slide_graph.zig b/zig/src/server/slide_graph.zig
index 596da2b110..e975f5b081 100644
--- a/zig/src/server/slide_graph.zig
+++ b/zig/src/server/slide_graph.zig
@@ -1,7 +1,7 @@
 //! The Sliding Weights fact graph: what was taught, how far each lesson is, where its neurons went; never the weights.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const slide_model = @import("slide_model.zig");
 const Allocator = std.mem.Allocator;
 const Io = std.Io;
diff --git a/zig/src/server/slide_lesson.zig b/zig/src/server/slide_lesson.zig
index fbcb5eb609..cb0784abca 100644
--- a/zig/src/server/slide_lesson.zig
+++ b/zig/src/server/slide_lesson.zig
@@ -1,7 +1,7 @@
 //! A fact's lesson written by the model itself: the teller's questions, short answers, near misses, keep prompts.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const chat = @import("chat.zig");
 const prompt = @import("prompt.zig");
 const errors = @import("errors.zig");
diff --git a/zig/src/server/slide_model.zig b/zig/src/server/slide_model.zig
index 274f9bb59b..014fcca7c1 100644
--- a/zig/src/server/slide_model.zig
+++ b/zig/src/server/slide_model.zig
@@ -1,6 +1,6 @@
 //! The served model as the Sliding Weights view draws it: its layers, its pockets, and the shards that hold them.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const Allocator = std.mem.Allocator;
 const Io = std.Io;
 
diff --git a/zig/src/server/slide_teacher.zig b/zig/src/server/slide_teacher.zig
index a6743a0ce2..7d1534e111 100644
--- a/zig/src/server/slide_teacher.zig
+++ b/zig/src/server/slide_teacher.zig
@@ -1,7 +1,7 @@
 //! What every lesson shares, written once: keep prompts with the model's answers, the personal bank, the turn's end.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const log = @import("log.zig");
 const prompts = @import("slide_prompts.zig");
 const slide_ask = @import("slide_ask.zig");
diff --git a/zig/src/server/slide_think.zig b/zig/src/server/slide_think.zig
index dce2cb1ba6..26f361597b 100644
--- a/zig/src/server/slide_think.zig
+++ b/zig/src/server/slide_think.zig
@@ -1,7 +1,7 @@
 //! A lesson with thinking on: the model's reasoning to where it restates the question, then a learned recall line.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const chat = @import("chat.zig");
 const prompt = @import("prompt.zig");
 const errors = @import("errors.zig");
diff --git a/zig/src/server/sse.zig b/zig/src/server/sse.zig
index de30ac1212..0942a7e145 100644
--- a/zig/src/server/sse.zig
+++ b/zig/src/server/sse.zig
@@ -1,6 +1,6 @@
 //! Server-sent events as the Python server frames them: the head, ``data:`` frames, typed ``event:`` frames, ``[DONE]``.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const Conn = @import("http_conn.zig").Conn;
 const Allocator = std.mem.Allocator;
 
diff --git a/zig/src/server/status_routes.zig b/zig/src/server/status_routes.zig
index 89ee5c8488..9c220f4445 100644
--- a/zig/src/server/status_routes.zig
+++ b/zig/src/server/status_routes.zig
@@ -1,7 +1,7 @@
 //! GET /health, /v1/models, /metrics, and the opt-in dashboard.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const live = @import("live.zig");
 const routes = @import("routes.zig");
 const Server = @import("server.zig").Server;
diff --git a/zig/src/server/tokens.zig b/zig/src/server/tokens.zig
index 3a2e351921..81a3deed62 100644
--- a/zig/src/server/tokens.zig
+++ b/zig/src/server/tokens.zig
@@ -1,6 +1,6 @@
 //! vLLM's /tokenize and /detokenize (the ids the chat and completion routes would run), and a reply's token SHA.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const fields = @import("fields.zig");
 const messages = @import("messages.zig");
diff --git a/zig/src/server/tool_grammar.zig b/zig/src/server/tool_grammar.zig
index 27b76df1c9..f087833d5e 100644
--- a/zig/src/server/tool_grammar.zig
+++ b/zig/src/server/tool_grammar.zig
@@ -1,7 +1,7 @@
 //! tool_choice "required" or a named function as a grammar: calls in the template's markup, arguments in their schema.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const prompt = @import("prompt.zig");
 const tool_specs = @import("tool_specs.zig");
diff --git a/zig/src/server/tool_params.zig b/zig/src/server/tool_params.zig
index c59d11cfbe..51352dc5ec 100644
--- a/zig/src/server/tool_params.zig
+++ b/zig/src/server/tool_params.zig
@@ -1,6 +1,6 @@
 //! Typed tool parameters: XML parameter text decoded by the offered schema (``tool_parameters.py``).
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const reply_text = @import("reply_text.zig");
 const tool_specs = @import("tool_specs.zig");
 const Value = json.Value;
@@ -324,7 +324,7 @@ const Literal = struct {
     fn appendCode(a: Allocator, out: *std.ArrayList(u8), v: u21) Error!void {
         if (v > 0x10ffff) return error.Invalid;
         var buf: [4]u8 = undefined;
-        const n = @import("json_parse.zig").wtf8Encode(v, &buf);
+        const n = @import("json").wtf8Encode(v, &buf);
         try out.appendSlice(a, buf[0..n]);
     }
 
diff --git a/zig/src/server/tool_parse.zig b/zig/src/server/tool_parse.zig
index b660b3b73d..b496d0851a 100644
--- a/zig/src/server/tool_parse.zig
+++ b/zig/src/server/tool_parse.zig
@@ -1,6 +1,6 @@
 //! Tool calls in a finished reply, every family's markup, as OpenAI tool_calls (``tools.parse_tool_calls_from_content``).
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const ids = @import("ids.zig");
 const reply_text = @import("reply_text.zig");
 const tool_params = @import("tool_params.zig");
diff --git a/zig/src/server/tool_parse_test.zig b/zig/src/server/tool_parse_test.zig
index 7481f1e311..f503f88006 100644
--- a/zig/src/server/tool_parse_test.zig
+++ b/zig/src/server/tool_parse_test.zig
@@ -1,6 +1,6 @@
 //! The tool_parse tests, as their own test binary: whole-reply parses and the close-call helpers.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const tool_parse = @import("tool_parse.zig");
 const parse = tool_parse.parse;
 const closeCall = tool_parse.closeCall;
diff --git a/zig/src/server/tool_specs.zig b/zig/src/server/tool_specs.zig
index 1a20f48025..cca2610dd8 100644
--- a/zig/src/server/tool_specs.zig
+++ b/zig/src/server/tool_specs.zig
@@ -1,6 +1,6 @@
 //! Offered tools and tool_choice as the template should see them (``tools.active_tool_specs``).
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const Value = json.Value;
 const Cx = errors.Cx;
diff --git a/zig/src/server/tool_stream.zig b/zig/src/server/tool_stream.zig
index 74b8610e7b..b55659c239 100644
--- a/zig/src/server/tool_stream.zig
+++ b/zig/src/server/tool_stream.zig
@@ -1,6 +1,6 @@
 //! Tool calls while they are written: XML calls as argument deltas, and the one-call policy's text filter.
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const ids = @import("ids.zig");
 const reply_text = @import("reply_text.zig");
 const tool_params = @import("tool_params.zig");
diff --git a/zig/src/server/tool_stream_test.zig b/zig/src/server/tool_stream_test.zig
index e1ed215f02..d33ef34813 100644
--- a/zig/src/server/tool_stream_test.zig
+++ b/zig/src/server/tool_stream_test.zig
@@ -1,5 +1,5 @@
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const tool_params = @import("tool_params.zig");
 const stream = @import("tool_stream.zig");
 const Streamer = stream.Streamer;
diff --git a/zig/src/server/tool_streaming.zig b/zig/src/server/tool_streaming.zig
index 700caedd7c..48fe167eea 100644
--- a/zig/src/server/tool_streaming.zig
+++ b/zig/src/server/tool_streaming.zig
@@ -1,6 +1,6 @@
 //! The streaming half of tool calls: each finished call's opening delta, then its arguments (``stream_tool_call_deltas``).
 const std = @import("std");
-const json = @import("json.zig");
+const json = @import("json");
 const tool_specs = @import("tool_specs.zig");
 const Value = json.Value;
 const Allocator = std.mem.Allocator;
diff --git a/zig/src/server/warm.zig b/zig/src/server/warm.zig
index f02f8a0c7d..1bf80ce4b2 100644
--- a/zig/src/server/warm.zig
+++ b/zig/src/server/warm.zig
@@ -1,7 +1,7 @@
 //! After a chat reply, the next turn's shared prompt prefilled in the background, so that turn resumes past the reply.
 const std = @import("std");
 const api = @import("engine_api");
-const json = @import("json.zig");
+const json = @import("json");
 const errors = @import("errors.zig");
 const prompt_mod = @import("prompt.zig");
 const chat = @import("chat.zig");
diff --git a/zig/tests/server/build.sh b/zig/tests/server/build.sh
index 63dfaa28c2..b3587d521c 100755
--- a/zig/tests/server/build.sh
+++ b/zig/tests/server/build.sh
@@ -11,10 +11,10 @@ version="$(sed -n 's/^[[:space:]]*\.version = "\([0-9]*\.[0-9]*\.[0-9]*\)",$/\1/
 options="$out/build_options.zig"
 printf 'pub const version = "%s";\n' "$version" > "$options"
 core=(--dep lanes "-Mengine_api=$root/zig/src/core/engine_api.zig" "-Mlanes=$root/zig/src/core/lanes/lanes.zig"
-      "-Mtokenizer=$root/zig/src/core/tokenizer/tokenizer.zig" "-Mtemplate=$root/zig/src/core/template/template.zig")
+      "-Mtokenizer=$root/zig/src/core/tokenizer/tokenizer.zig" "-Mtemplate=$root/zig/src/core/template/template.zig" "-Mjson=$root/zig/src/server/json.zig")
 "$zig" build-exe -lc -O "${OPT:-ReleaseSafe}" --dep server --dep engine_api "-Mroot=$root/zig/tests/server/fake_serve.zig" \
-  --dep engine_api --dep tokenizer --dep template "-Mserver=$root/zig/src/server/root.zig" "${core[@]}" \
+  --dep engine_api --dep tokenizer --dep template --dep json "-Mserver=$root/zig/src/server/root.zig" "${core[@]}" \
   --name fake_serve -femit-bin="$out/fake_serve"
-"$zig" build-exe -lc -O "${OPT:-ReleaseSafe}" --dep engine_api --dep tokenizer --dep template --dep native_engines --dep build_options \
+"$zig" build-exe -lc -O "${OPT:-ReleaseSafe}" --dep engine_api --dep tokenizer --dep template --dep json --dep native_engines --dep build_options \
   "-Mroot=$root/zig/src/server/main.zig" --dep engine_api "-Mnative_engines=$root/zig/src/native/none.zig" "${core[@]}" \
   "-Mbuild_options=$options" --name tensorfold-native -femit-bin="$out/tensorfold-native"
diff --git a/zig/tests/server/zig_test.sh b/zig/tests/server/zig_test.sh
index 4f583f439c..687071980d 100755
--- a/zig/tests/server/zig_test.sh
+++ b/zig/tests/server/zig_test.sh
@@ -3,10 +3,12 @@
 set -euo pipefail
 zig="${ZIG:-zig}"
 root="$(cd "$(dirname "$0")/../../.." && pwd)"
-"$zig" test -lc --dep engine_api --dep tokenizer --dep template \
+"$zig" test -lc --dep engine_api --dep tokenizer --dep template --dep json \
   "-Mroot=$root/zig/src/server/root.zig" \
+  "-Mjson=$root/zig/src/server/json.zig" \
   --dep lanes "-Mengine_api=$root/zig/src/core/engine_api.zig" \
   "-Mlanes=$root/zig/src/core/lanes/lanes.zig" \
   "-Mtokenizer=$root/zig/src/core/tokenizer/tokenizer.zig" \
   "-Mtemplate=$root/zig/src/core/template/template.zig" "$@"
+"$zig" test "$root/zig/src/server/json.zig"
 "$zig" test -lc --dep lanes "-Mroot=$root/zig/src/core/engine_api.zig" "-Mlanes=$root/zig/src/core/lanes/lanes.zig"