diff --git a/Cargo.lock b/Cargo.lock
index a096db6b..ade573b7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2242,7 +2242,7 @@ dependencies = [
 [[package]]
 name = "harness-gateway-client"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "async-trait",
  "bytes",
@@ -2258,7 +2258,7 @@ dependencies = [
 [[package]]
 name = "harness-plugin-loader"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "libloading 0.8.9",
  "runvil-plugin",
@@ -2269,7 +2269,7 @@ dependencies = [
 [[package]]
 name = "harness-runner"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "futures-util",
  "rand 0.9.5",
@@ -4064,7 +4064,7 @@ dependencies = [
 [[package]]
 name = "plugin-mcp"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "reqwest",
  "rmcp",
@@ -4088,7 +4088,7 @@ dependencies = [
 [[package]]
 name = "plugin-web"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "async-trait",
  "encoding_rs",
@@ -4734,7 +4734,7 @@ dependencies = [
 [[package]]
 name = "runvil"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "harness-plugin-loader",
  "harness-runner",
@@ -4745,7 +4745,7 @@ dependencies = [
 [[package]]
 name = "runvil-engine"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "runvil-lua",
  "runvil-model-client",
@@ -4758,7 +4758,7 @@ dependencies = [
 [[package]]
 name = "runvil-lua"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "mlua",
  "runvil-markdown",
@@ -4772,7 +4772,7 @@ dependencies = [
 [[package]]
 name = "runvil-markdown"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "pulldown-cmark",
  "serde_json",
@@ -4782,7 +4782,7 @@ dependencies = [
 [[package]]
 name = "runvil-model-client"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "runvil-types",
  "serde",
@@ -4792,7 +4792,7 @@ dependencies = [
 [[package]]
 name = "runvil-plugin"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "runvil-types",
  "runvil-vfs",
@@ -4815,19 +4815,20 @@ source = "git+https://github.com/cppalliance/runvil-plugin-api?rev=03a9fa37d2fe6
 [[package]]
 name = "runvil-prompt"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "pulldown-cmark",
  "runvil-lua",
  "runvil-types",
  "serde",
+ "serde_json",
  "serde_yaml_ng",
 ]
 
 [[package]]
 name = "runvil-runtime"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "mlua",
  "regex",
@@ -4845,7 +4846,7 @@ dependencies = [
 [[package]]
 name = "runvil-types"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 dependencies = [
  "serde",
  "serde_json",
@@ -4855,7 +4856,7 @@ dependencies = [
 [[package]]
 name = "runvil-vfs"
 version = "0.3.0"
-source = "git+https://github.com/cppalliance/runvil-harness?rev=7147e709f603b81786fb2d702bf50c4d9a88d62b#7147e709f603b81786fb2d702bf50c4d9a88d62b"
+source = "git+https://github.com/cppalliance/runvil-harness?rev=0d938885abc7fb293ae449a787c50e7c7eb60e92#0d938885abc7fb293ae449a787c50e7c7eb60e92"
 
 [[package]]
 name = "rust-embed"
diff --git a/Cargo.toml b/Cargo.toml
index e4cfdb31..8a4144c2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -25,10 +25,10 @@ repository = "https://github.com/cppalliance/runvil-workshop"
 # in. All four name one commit, because two commits would be two copies
 # of every type the crates share. `version` beside `git` keeps cargo-deny's
 # wildcard check quiet.
-runvil = { version = "0.3.0", git = "https://github.com/cppalliance/runvil-harness", rev = "7147e709f603b81786fb2d702bf50c4d9a88d62b" }
-harness-gateway-client = { version = "0.3.0", git = "https://github.com/cppalliance/runvil-harness", rev = "7147e709f603b81786fb2d702bf50c4d9a88d62b" }
-plugin-web = { version = "0.3.0", git = "https://github.com/cppalliance/runvil-harness", rev = "7147e709f603b81786fb2d702bf50c4d9a88d62b" }
-plugin-mcp = { version = "0.3.0", git = "https://github.com/cppalliance/runvil-harness", rev = "7147e709f603b81786fb2d702bf50c4d9a88d62b" }
+runvil = { version = "0.3.0", git = "https://github.com/cppalliance/runvil-harness", rev = "0d938885abc7fb293ae449a787c50e7c7eb60e92" }
+harness-gateway-client = { version = "0.3.0", git = "https://github.com/cppalliance/runvil-harness", rev = "0d938885abc7fb293ae449a787c50e7c7eb60e92" }
+plugin-web = { version = "0.3.0", git = "https://github.com/cppalliance/runvil-harness", rev = "0d938885abc7fb293ae449a787c50e7c7eb60e92" }
+plugin-mcp = { version = "0.3.0", git = "https://github.com/cppalliance/runvil-harness", rev = "0d938885abc7fb293ae449a787c50e7c7eb60e92" }
 # The safe layer over the C Plugin contract, version 0.4, from its own
 # repository, pinned by commit. Only the library Plugin crates under
 # `crates/workshop/` name it, for `export_plugin!`. The commit is the one
diff --git a/crates/workshop/server/src/routes/prompts-tests.rs b/crates/workshop/server/src/routes/prompts-tests.rs
index cdd70a0c..482a7c65 100644
--- a/crates/workshop/server/src/routes/prompts-tests.rs
+++ b/crates/workshop/server/src/routes/prompts-tests.rs
@@ -39,9 +39,6 @@ name: full
 description: does everything
 runvil: 0
 max_tool_iterations: 5
-input:
-  path: paper.md
-  description: the paper
 output:
   path: out.md
   description: the result
@@ -50,13 +47,16 @@ uses:
   - fs
   - acme/poop
 args:
-  topic:
-    type: string
-    description: the topic
-  count:
-    type: integer
-    optional: true
-    default: 3
+  type: object
+  properties:
+    topic:
+      type: string
+      description: the topic
+    count:
+      type: integer
+      default: 3
+  required:
+    - topic
 models:
   strong:
     min_context: 200000
@@ -78,10 +78,6 @@ async fn a_full_frontmatter_prompt_answers_every_contract_section() {
     assert_eq!(json["description"], "does everything");
     assert_eq!(json["runvil"], 0);
     assert_eq!(json["max_tool_iterations"], 5);
-    assert_eq!(
-        json["input"],
-        serde_json::json!({ "path": "paper.md", "description": "the paper" })
-    );
     assert_eq!(
         json["output"],
         serde_json::json!({ "path": "out.md", "description": "the result" })
@@ -96,14 +92,19 @@ async fn a_full_frontmatter_prompt_answers_every_contract_section() {
             { "id": "poop" },
         ])
     );
+    // The declaration is sent as JSON Schema: every object node writes
+    // `additionalProperties`, and `required` lists the fields a caller
+    // must send.
     assert_eq!(
         json["args"],
         serde_json::json!({
-            "implicit": false,
-            "fields": [
-                { "name": "count", "type": "integer", "optional": true, "default": 3, "description": null },
-                { "name": "topic", "type": "string", "optional": false, "default": null, "description": "the topic" },
-            ],
+            "type": "object",
+            "properties": {
+                "count": { "type": "integer", "default": 3 },
+                "topic": { "type": "string", "description": "the topic" },
+            },
+            "required": ["topic"],
+            "additionalProperties": false,
         })
     );
     assert_eq!(
@@ -147,7 +148,7 @@ fn an_internal_parse_failure_names_no_prompt_line() {
 }
 
 #[tokio::test]
-async fn a_prompt_without_args_yields_the_implicit_prose_field() {
+async fn a_prompt_without_args_yields_the_default_declaration() {
     let text = "---\nname: plain\ndescription: no args\n---\n\n## S\n\np\n";
     let body = serde_json::json!({ "name": "plain", "text": text });
     let (status, json) = post_contract(body).await;
@@ -155,10 +156,11 @@ async fn a_prompt_without_args_yields_the_implicit_prose_field() {
     assert_eq!(
         json["args"],
         serde_json::json!({
-            "implicit": true,
-            "fields": [
-                { "name": "prose", "type": "string", "optional": true, "default": null, "description": "Freeform input for this prompt" },
-            ],
+            "type": "object",
+            "properties": {
+                "text": { "type": "string", "description": "Freeform text for this prompt" },
+            },
+            "additionalProperties": false,
         })
     );
     assert_eq!(
@@ -195,7 +197,6 @@ async fn the_dto_serializes_absent_declarations_as_nulls() {
     let (status, json) = post_contract(body).await;
     assert_eq!(status, StatusCode::OK);
     // Absent declarations serialize as explicit nulls, not missing keys.
-    assert!(json["input"].is_null());
     assert!(json["output"].is_null());
     assert!(json["max_tool_iterations"].is_null());
     assert!(json["runvil"].is_null());
diff --git a/crates/workshop/server/src/routes/prompts.rs b/crates/workshop/server/src/routes/prompts.rs
index 65028f9d..6ca8f818 100644
--- a/crates/workshop/server/src/routes/prompts.rs
+++ b/crates/workshop/server/src/routes/prompts.rs
@@ -5,7 +5,9 @@
 //! posted markdown into the contract the Run window renders, or a `422`
 //! envelope naming the parse failure kind and line. The parser's own
 //! types are `Deserialize`-only, so the wire DTO is hand-written
-//! `Serialize` structs built from [`Frontmatter`] accessors.
+//! `Serialize` structs built from [`Frontmatter`] accessors. Its `args`
+//! field is the JSON Schema that
+//! [`ArgsSchema::as_json`](runvil::prompt::ArgsSchema::as_json) gives.
 
 use axum::Json;
 use axum::http::StatusCode;
@@ -16,7 +18,7 @@ use serde::{Deserialize, Serialize};
 use runvil::Prompt;
 use runvil::model::ModelRole;
 use runvil::packs::PackRef;
-use runvil::prompt::{ArgDecl, ArgsDecl, FileDecl, Frontmatter, RoleRequirements};
+use runvil::prompt::{FileDecl, Frontmatter, RoleRequirements};
 
 use crate::error::AppError;
 
@@ -48,19 +50,18 @@ struct ContractResponse {
     runvil: Option<u32>,
     /// The declared tool-loop cap; `null` for the runtime default.
     max_tool_iterations: Option<u32>,
-    /// The declared input file; `null` when absent.
-    input: Option<FileDto>,
     /// The declared output file; `null` when absent.
     output: Option<FileDto>,
     /// The declared Packs, in declaration order.
     uses: Vec<PackDto>,
-    /// The typed args declaration.
-    args: ArgsDto,
+    /// The `args` declaration as JSON Schema. The root is an object node,
+    /// and its `properties` are the prompt's arguments by name.
+    args: serde_json::Value,
     /// The declared model roles, sorted by label.
     models: Vec<ModelDto>,
 }
 
-/// A declared input or output file.
+/// The declared output file.
 #[derive(Debug, Serialize)]
 struct FileDto {
     /// The store-internal path.
@@ -93,60 +94,6 @@ impl From<&PackRef> for PackDto {
     }
 }
 
-/// The typed args declaration.
-#[derive(Debug, Serialize)]
-struct ArgsDto {
-    /// True when the declaration is the implicit default (no `args:` key).
-    implicit: bool,
-    /// The declared fields, sorted by name.
-    fields: Vec<ArgDto>,
-}
-
-impl From<&ArgsDecl> for ArgsDto {
-    fn from(decl: &ArgsDecl) -> Self {
-        Self {
-            implicit: decl.is_default(),
-            fields: decl
-                .iter()
-                .map(|(name, arg)| ArgDto::new(name, arg))
-                .collect(),
-        }
-    }
-}
-
-/// One declared arg.
-#[derive(Debug, Serialize)]
-struct ArgDto {
-    /// The arg name.
-    name: String,
-    /// The declared type (`string`, `boolean`, `integer`, `number`).
-    #[serde(rename = "type")]
-    kind: String,
-    /// Whether a call may omit the field.
-    optional: bool,
-    /// The declared default; `null` when absent.
-    default: Option<serde_json::Value>,
-    /// The human-readable description; `null` when absent.
-    description: Option<String>,
-}
-
-impl ArgDto {
-    /// Builds the DTO for the arg declared under `name`.
-    fn new(name: &str, decl: &ArgDecl) -> Self {
-        Self {
-            name: name.to_owned(),
-            kind: decl.kind().to_string(),
-            optional: decl.is_optional(),
-            // A declared default is validated against the declared type
-            // at parse, so it is always a JSON-representable scalar.
-            default: decl
-                .default()
-                .and_then(|value| serde_json::to_value(value).ok()),
-            description: decl.description().map(str::to_owned),
-        }
-    }
-}
-
 /// The requirements a prompt declares for one model role.
 #[derive(Debug, Serialize)]
 struct ModelDto {
@@ -178,10 +125,9 @@ impl From<&Frontmatter> for ContractResponse {
             max_tool_iterations: frontmatter
                 .max_tool_iterations()
                 .map(std::num::NonZeroU32::get),
-            input: frontmatter.input().map(FileDto::from),
             output: frontmatter.output().map(FileDto::from),
             uses: frontmatter.uses().iter().map(PackDto::from).collect(),
-            args: ArgsDto::from(frontmatter.args()),
+            args: frontmatter.args().as_json().clone(),
             models: ModelRole::ALL
                 .into_iter()
                 .filter_map(|role| {
diff --git a/crates/workshop/ui/src/parts/run/run-panel.ts b/crates/workshop/ui/src/parts/run/run-panel.ts
index 387b88f0..97d668ab 100644
--- a/crates/workshop/ui/src/parts/run/run-panel.ts
+++ b/crates/workshop/ui/src/parts/run/run-panel.ts
@@ -11,8 +11,7 @@
 // "Prompt" label is for screen readers only, the empty and error states
 // are text lines with Browse... and Choose Prompt as inline links, a
 // droppable drag marks the panel with a drag-over overlay class, and the
-// typed-path dialogs (Choose Prompt, Choose Input) are Cursor's form
-// modal, Cancel first.
+// typed-path dialog (Choose Prompt) is Cursor's form modal, Cancel first.
 //
 // The panel never reads disk: prompt text arrives through the confined
 // GET /workspace/file and is posted to POST /prompts/contract. Prompts
@@ -83,7 +82,7 @@ export class RunPanel extends WorkshopPart {
   private contract: RunContract | null = null;
   private failure: string | null = null;
   private promptPath: string | null = null;
-  // The open Choose Prompt / input Browse dialog, dismissed with the panel.
+  // The open Choose Prompt dialog, dismissed with the panel.
   private dialog: { dispose(): void } | null = null;
 
   // Holds the toolbar, body, and footer. It is the width container the rows
@@ -328,39 +327,6 @@ export class RunPanel extends WorkshopPart {
     await this.load(path);
   }
 
-  /** The input row's Browse: fills the field, reading nothing. */
-  private browseInput(field: HTMLInputElement): void {
-    if (window.__TAURI_INTERNALS__ !== undefined) {
-      void open({ directory: false, title: "Choose Input" }).then((picked) => {
-        if (typeof picked === "string") {
-          field.value = picked;
-        }
-      });
-      return;
-    }
-    this.dialog?.dispose();
-    this.dialog = showPanelDialog({
-      container: this.element,
-      classPrefix: "ws-run-input",
-      titleId: "run-input-title",
-      title: "Choose Input",
-      message: "Enter the full path of the input file.",
-      skin: "form",
-      field: { id: "run-input-path", label: "Input path" },
-      buttons: [
-        { label: "Cancel", run: () => undefined },
-        {
-          label: "Choose",
-          primary: true,
-          requiresValue: true,
-          run: (value) => {
-            field.value = value;
-          },
-        },
-      ],
-    });
-  }
-
   /** Paints the body's state-dependent content and the Run button. */
   private render(): void {
     this.promptField.value = this.promptPath ?? "";
@@ -398,9 +364,7 @@ export class RunPanel extends WorkshopPart {
       return;
     }
     if (this.contract !== null) {
-      renderContractRows(this.body, this.contract, {
-        browseInput: (field) => this.browseInput(field),
-      });
+      renderContractRows(this.body, this.contract);
     }
   }
 }
diff --git a/crates/workshop/ui/src/parts/run/run-rows.ts b/crates/workshop/ui/src/parts/run/run-rows.ts
index 0c4c05f3..4afbd049 100644
--- a/crates/workshop/ui/src/parts/run/run-rows.ts
+++ b/crates/workshop/ui/src/parts/run/run-rows.ts
@@ -2,9 +2,9 @@
 // pure DOM building over the narrowed RunContract. Every frontmatter
 // key present in the prompt except `uses`, which has nothing to
 // bind, appears as exactly one row: name, description, and runvil
-// read-only; input a text field plus Browse; output a text field; one
-// control per arg by type with required markers and defaults (the
-// implicit declaration is the single prose box); model roles
+// read-only; output a text field; one row for each top-level property
+// of the `args` schema, its control chosen by the property's type, with
+// the required marker and the default prefilled; model roles
 // read-only; max_tool_iterations numeric with the runtime-default
 // placeholder. No bind-time validation runs here - validation is the
 // parser's alone.
@@ -15,18 +15,15 @@
 // side. A boolean arg is a `.switch` button, as Cursor's settings toggles
 // are.
 
-import type { RunContract, RunContractArg } from "../../services/run-api";
+import type { RunContract, RunContractSchema } from "../../services/run-api";
 
-/** The panel's hooks the rows need. */
-export interface RunRowsOptions {
-  /** Fills the input row's field through the panel's file-pick flow. */
-  readonly browseInput: (field: HTMLInputElement) => void;
-}
+/** The Engine's name for an argument that holds free text. */
+const TEXT_ARG = "text";
 
 /** What a row shows beside its label. */
 interface RowDetails {
   /** The second line under the label; blank or absent draws none. */
-  readonly description?: string | null;
+  readonly description?: string;
   /** Draws the required marker beside the label. */
   readonly required?: boolean;
 }
@@ -51,7 +48,7 @@ function row(label: string, controls: readonly Node[], details: RowDetails = {})
     title.appendChild(requiredMarker());
   }
   text.appendChild(title);
-  if (details.description !== undefined && details.description !== null && details.description.length > 0) {
+  if (details.description !== undefined && details.description.length > 0) {
     const description = document.createElement("div");
     description.className = "ws-run-panel__row-description";
     description.textContent = details.description;
@@ -83,7 +80,16 @@ function textField(value: string, placeholder = ""): HTMLInputElement {
   return field;
 }
 
-/** The required marker on a non-optional arg. */
+/** A multiline box with the shared control skin. */
+function multilineBox(value: string, placeholder = ""): HTMLTextAreaElement {
+  const box = document.createElement("textarea");
+  box.className = "input ws-run-panel__prose";
+  box.value = value;
+  box.placeholder = placeholder;
+  return box;
+}
+
+/** The required marker on an arg the schema's `required` list names. */
 function requiredMarker(): HTMLElement {
   const marker = document.createElement("span");
   marker.className = "ws-run-panel__required";
@@ -96,12 +102,12 @@ function requiredMarker(): HTMLElement {
  * A boolean arg's control: Cursor's switch, a `<button role="switch">` whose
  * `aria-checked` is the value. A click or Space/Enter flips it.
  */
-function booleanSwitch(arg: RunContractArg): HTMLButtonElement {
+function booleanSwitch(name: string, arg: RunContractSchema): HTMLButtonElement {
   const toggle = document.createElement("button");
   toggle.type = "button";
   toggle.className = "switch ws-run-panel__switch";
   toggle.setAttribute("role", "switch");
-  toggle.setAttribute("aria-label", arg.name);
+  toggle.setAttribute("aria-label", name);
   toggle.setAttribute("aria-checked", String(arg.default === true));
   toggle.addEventListener("click", () => {
     toggle.setAttribute("aria-checked", String(toggle.getAttribute("aria-checked") !== "true"));
@@ -109,10 +115,10 @@ function booleanSwitch(arg: RunContractArg): HTMLButtonElement {
   return toggle;
 }
 
-/** One arg's control by its declared type, prefilled from its default. */
-function argControl(arg: RunContractArg): HTMLElement {
+/** The control of the arg `name` by its declared type, prefilled from its default. */
+function argControl(name: string, arg: RunContractSchema): HTMLElement {
   if (arg.type === "boolean") {
-    return booleanSwitch(arg);
+    return booleanSwitch(name, arg);
   }
   if (arg.type === "integer" || arg.type === "number") {
     const field = document.createElement("input");
@@ -126,18 +132,21 @@ function argControl(arg: RunContractArg): HTMLElement {
     }
     return field;
   }
-  return textField(typeof arg.default === "string" ? arg.default : "");
+  if (arg.type === "array" || arg.type === "object") {
+    // A list or an object is typed as JSON text.
+    return multilineBox(arg.default === undefined ? "" : JSON.stringify(arg.default), "JSON");
+  }
+  const value = typeof arg.default === "string" ? arg.default : "";
+  // An `enum` shows its allowed values in the empty control.
+  const placeholder = arg.enum?.join(" | ") ?? "";
+  return name === TEXT_ARG ? multilineBox(value, placeholder) : textField(value, placeholder);
 }
 
 /**
  * Renders every contract section into `container`. The caller clears
  * the container first; rows append in contract order.
  */
-export function renderContractRows(
-  container: HTMLElement,
-  contract: RunContract,
-  options: RunRowsOptions,
-): void {
+export function renderContractRows(container: HTMLElement, contract: RunContract): void {
   const rows = document.createElement("div");
   rows.className = "ws-run-panel__rows";
 
@@ -149,36 +158,19 @@ export function renderContractRows(
     rows.appendChild(row("runvil", [readOnly(String(contract.runvil))]));
   }
 
-  const inputField = textField(contract.input?.path ?? "", contract.input?.description ?? "");
-  const inputBrowse = document.createElement("button");
-  inputBrowse.type = "button";
-  inputBrowse.className = "button button-outline button-sm ws-run-panel__input-browse";
-  inputBrowse.textContent = "Browse...";
-  inputBrowse.addEventListener("click", () => options.browseInput(inputField));
-  rows.appendChild(row("input", [inputField, inputBrowse]));
-
   rows.appendChild(
     row("output", [textField(contract.output?.path ?? "", contract.output?.description ?? "")]),
   );
 
-  if (contract.args.implicit) {
-    // The implicit declaration is the single prose field, a multiline box.
-    const prose = document.createElement("textarea");
-    prose.className = "input ws-run-panel__prose";
-    const proseField = contract.args.fields[0];
-    if (proseField !== undefined && typeof proseField.default === "string") {
-      prose.value = proseField.default;
-    }
+  const required = contract.args.required ?? [];
+  for (const [name, arg] of Object.entries(contract.args.properties ?? {})) {
+    // The description is a visible second line under the label, not a tooltip.
     rows.appendChild(
-      row(proseField?.name ?? "prose", [prose], { description: proseField?.description ?? null }),
+      row(name, [argControl(name, arg)], {
+        description: arg.description,
+        required: required.includes(name),
+      }),
     );
-  } else {
-    for (const arg of contract.args.fields) {
-      // The description is a visible second line under the label, not a tooltip.
-      rows.appendChild(
-        row(arg.name, [argControl(arg)], { description: arg.description, required: !arg.optional }),
-      );
-    }
   }
 
   for (const model of contract.models) {
diff --git a/crates/workshop/ui/src/services/run-api.ts b/crates/workshop/ui/src/services/run-api.ts
index 814fa10d..96a1c7fc 100644
--- a/crates/workshop/ui/src/services/run-api.ts
+++ b/crates/workshop/ui/src/services/run-api.ts
@@ -11,7 +11,7 @@
 import { CatalogError, ErrorCatalog } from "./error-catalog";
 import { errorCode, errorMessage, isRecord, readJson, request } from "./json-request";
 
-/** A declared input or output file. */
+/** The declared output file. */
 export interface RunContractFile {
   readonly path: string;
   readonly description: string;
@@ -22,24 +22,35 @@ export interface RunContractPack {
   readonly id: string;
 }
 
-/** The declared arg types the wire format allows. */
-export type RunContractArgType = "string" | "boolean" | "integer" | "number";
+/** The words a schema node's `type` may hold. */
+export type RunContractSchemaType =
+  | "string"
+  | "boolean"
+  | "integer"
+  | "number"
+  | "array"
+  | "object";
 
-/** One declared arg. */
-export interface RunContractArg {
-  readonly name: string;
-  readonly type: RunContractArgType;
-  readonly optional: boolean;
-  /** The declared default; null when absent. */
-  readonly default: string | number | boolean | null;
-  /** The human-readable description; null when absent. */
-  readonly description: string | null;
-}
-
-/** The typed args declaration; implicit names the single prose field. */
-export interface RunContractArgs {
-  readonly implicit: boolean;
-  readonly fields: readonly RunContractArg[];
+/**
+ * One node of the `args` declaration, a subset of JSON Schema. The root
+ * is an object node whose properties are the prompt's arguments.
+ */
+export interface RunContractSchema {
+  readonly type: RunContractSchemaType;
+  /** An object node's fields by name, in the order the server sends them. */
+  readonly properties?: Readonly<Record<string, RunContractSchema>>;
+  /** The names of the fields an object node requires. */
+  readonly required?: readonly string[];
+  /** Whether an object node takes fields it does not declare. */
+  readonly additionalProperties?: boolean;
+  /** The node of each item of an array node. */
+  readonly items?: RunContractSchema;
+  /** The values a string or integer node allows. */
+  readonly enum?: readonly (string | number)[];
+  /** The human-readable description. */
+  readonly description?: string;
+  /** The JSON value a field takes when the caller leaves it out. */
+  readonly default?: unknown;
 }
 
 /** The requirements a prompt declares for one model role. */
@@ -60,10 +71,10 @@ export interface RunContract {
   readonly runvil: number | null;
   /** The declared tool-loop cap; null for the runtime default. */
   readonly maxToolIterations: number | null;
-  readonly input: RunContractFile | null;
   readonly output: RunContractFile | null;
   readonly uses: readonly RunContractPack[];
-  readonly args: RunContractArgs;
+  /** The `args` declaration: an object node. */
+  readonly args: RunContractSchema;
   readonly models: readonly RunContractModel[];
 }
 
@@ -89,58 +100,99 @@ function parsePack(value: unknown): RunContractPack | null {
   return { id };
 }
 
-const ARG_TYPES: readonly string[] = ["string", "boolean", "integer", "number"];
+function parseSchemaType(value: unknown): RunContractSchemaType | null {
+  switch (value) {
+    case "string":
+    case "boolean":
+    case "integer":
+    case "number":
+    case "array":
+    case "object":
+      return value;
+    default:
+      return null;
+  }
+}
 
-function parseArg(value: unknown): RunContractArg | null {
+function parseProperties(value: unknown): Record<string, RunContractSchema> | null {
   if (!isRecord(value)) {
     return null;
   }
-  const { name, type, optional } = value;
-  if (typeof name !== "string" || typeof type !== "string" || !ARG_TYPES.includes(type)) {
-    return null;
+  const nodes: [string, RunContractSchema][] = [];
+  for (const [name, field] of Object.entries(value)) {
+    const node = parseSchema(field);
+    if (node === null) {
+      return null;
+    }
+    nodes.push([name, node]);
   }
-  if (typeof optional !== "boolean") {
+  return Object.fromEntries(nodes);
+}
+
+function parseRequired(value: unknown): string[] | null {
+  if (!Array.isArray(value)) {
     return null;
   }
-  const defaultValue = value.default;
-  if (
-    defaultValue !== null &&
-    typeof defaultValue !== "string" &&
-    typeof defaultValue !== "number" &&
-    typeof defaultValue !== "boolean"
-  ) {
-    return null;
+  const names: string[] = [];
+  for (const name of value) {
+    if (typeof name !== "string") {
+      return null;
+    }
+    names.push(name);
   }
-  const description = value.description;
-  if (description !== null && typeof description !== "string") {
+  return names;
+}
+
+function parseEnum(value: unknown): (string | number)[] | null {
+  if (!Array.isArray(value)) {
     return null;
   }
-  return {
-    name,
-    type: type as RunContractArgType,
-    optional,
-    default: defaultValue,
-    description: description ?? null,
-  };
+  const choices: (string | number)[] = [];
+  for (const choice of value) {
+    if (typeof choice !== "string" && typeof choice !== "number") {
+      return null;
+    }
+    choices.push(choice);
+  }
+  return choices;
 }
 
-function parseArgs(value: unknown): RunContractArgs | null {
+/** Narrows one schema node and, through `properties` and `items`, every node under it. */
+function parseSchema(value: unknown): RunContractSchema | null {
   if (!isRecord(value)) {
     return null;
   }
-  const { implicit, fields } = value;
-  if (typeof implicit !== "boolean" || !Array.isArray(fields)) {
+  const type = parseSchemaType(value.type);
+  const properties = value.properties === undefined ? undefined : parseProperties(value.properties);
+  const required = value.required === undefined ? undefined : parseRequired(value.required);
+  const items = value.items === undefined ? undefined : parseSchema(value.items);
+  const choices = value.enum === undefined ? undefined : parseEnum(value.enum);
+  if (
+    type === null ||
+    properties === null ||
+    required === null ||
+    items === null ||
+    choices === null
+  ) {
     return null;
   }
-  const parsed: RunContractArg[] = [];
-  for (const field of fields) {
-    const arg = parseArg(field);
-    if (arg === null) {
-      return null;
-    }
-    parsed.push(arg);
+  const { additionalProperties, description } = value;
+  if (additionalProperties !== undefined && typeof additionalProperties !== "boolean") {
+    return null;
   }
-  return { implicit, fields: parsed };
+  if (description !== undefined && typeof description !== "string") {
+    return null;
+  }
+  return {
+    type,
+    properties,
+    required,
+    additionalProperties,
+    items,
+    enum: choices,
+    description,
+    default: value.default,
+  };
 }
 
 function parseModel(value: unknown): RunContractModel | null {
@@ -178,11 +230,7 @@ function parseContract(body: unknown): RunContract | null {
   if (max_tool_iterations !== null && typeof max_tool_iterations !== "number") {
     return null;
   }
-  const input = body.input === null ? null : parseFile(body.input);
   const output = body.output === null ? null : parseFile(body.output);
-  if (body.input !== null && input === null) {
-    return null;
-  }
   if (body.output !== null && output === null) {
     return null;
   }
@@ -197,8 +245,9 @@ function parseContract(body: unknown): RunContract | null {
     }
     parsedPacks.push(parsed);
   }
-  const args = parseArgs(body.args);
-  if (args === null) {
+  // The root of the declaration is an object node.
+  const args = parseSchema(body.args);
+  if (args === null || args.type !== "object") {
     return null;
   }
   const parsedModels: RunContractModel[] = [];
@@ -214,7 +263,6 @@ function parseContract(body: unknown): RunContract | null {
     description,
     runvil: runvil ?? null,
     maxToolIterations: max_tool_iterations ?? null,
-    input,
     output,
     uses: parsedPacks,
     args,
diff --git a/crates/workshop/ui/test/run-api.mjs b/crates/workshop/ui/test/run-api.mjs
index 3abe53d9..fb205784 100644
--- a/crates/workshop/ui/test/run-api.mjs
+++ b/crates/workshop/ui/test/run-api.mjs
@@ -2,9 +2,11 @@
 // Bundles the module with esbuild, imports it via a data URL, and drives it
 // against a scripted fetch. Covers: a full contract narrows field by field
 // (snake_case wire keys to the client's camelCase) and carries no tools
-// section; the implicit-args shape; narrowing rejects an unknown arg type; a
-// 422 envelope surfaces the server's code and message; a non-JSON answer and
-// a transport failure throw their typed variants.
+// section; the args schema narrows node by node, through properties and
+// items; the default declaration; narrowing rejects an unknown type word and
+// a root that is not an object; a 422 envelope surfaces the server's code and
+// message; a non-JSON answer and a transport failure throw their typed
+// variants.
 // Run: node --test test/run-api.mjs
 import path from "node:path";
 import { fileURLToPath } from "node:url";
@@ -36,16 +38,24 @@ const CONTRACT = {
   description: "Screens papers",
   runvil: 1,
   max_tool_iterations: 12,
-  input: { path: "in/papers.md", description: "the papers" },
   output: { path: "out/verdicts.md", description: "the verdicts" },
   uses: [{ id: "tools/web" }],
   args: {
-    implicit: false,
-    fields: [
-      { name: "topic", type: "string", optional: false, default: null, description: "the topic" },
-      { name: "deep", type: "boolean", optional: true, default: false, description: null },
-      { name: "limit", type: "integer", optional: true, default: 5, description: null },
-    ],
+    type: "object",
+    properties: {
+      deep: { type: "boolean", default: false },
+      focus: { type: "array", items: { type: "string" }, default: ["methods"] },
+      limit: { type: "integer", default: 5 },
+      opts: {
+        type: "object",
+        properties: { depth: { type: "integer", enum: [1, 2] } },
+        additionalProperties: true,
+      },
+      tone: { type: "string", enum: ["formal", "casual"] },
+      topic: { type: "string", description: "the topic" },
+    },
+    required: ["topic"],
+    additionalProperties: false,
   },
   models: [
     { label: "strong", min_context: 32000, thinking: true },
@@ -88,9 +98,8 @@ const json = (body, status = 200) => ({
       contract.maxToolIterations === 12,
   );
   check(
-    "input and output narrow",
-    contract.input?.path === "in/papers.md" &&
-      contract.output?.path === "out/verdicts.md" &&
+    "the output narrows",
+    contract.output?.path === "out/verdicts.md" &&
       contract.output?.description === "the verdicts",
   );
   check(
@@ -98,26 +107,56 @@ const json = (body, status = 200) => ({
     contract.uses.length === 1 && contract.uses[0].id === "tools/web",
   );
   check("a contract without tools narrows with no tools section", !("tools" in contract));
+  const { args } = contract;
+  check(
+    "the args root narrows as an object node with its required list",
+    args.type === "object" &&
+      args.additionalProperties === false &&
+      args.required?.join(",") === "topic",
+  );
+  // The Run window draws one row per property, top to bottom, so the
+  // narrowed properties must keep the order the server sends them.
   check(
-    "arg fields narrow with defaults and descriptions",
-    contract.args.implicit === false &&
-      contract.args.fields.length === 3 &&
-      contract.args.fields[0].name === "topic" &&
-      contract.args.fields[0].type === "string" &&
-      contract.args.fields[0].optional === false &&
-      contract.args.fields[1].default === false &&
-      contract.args.fields[2].type === "integer" &&
-      contract.args.fields[2].default === 5,
+    "the properties keep the order the server sends them",
+    Object.keys(args.properties ?? {}).join(",") === "deep,focus,limit,opts,tone,topic",
+  );
+  check(
+    "a property narrows with its type and default",
+    args.properties.topic.type === "string" &&
+      args.properties.topic.default === undefined &&
+      args.properties.deep.type === "boolean" &&
+      args.properties.deep.default === false &&
+      args.properties.limit.type === "integer" &&
+      args.properties.limit.default === 5,
   );
   // The Run window shows a described arg's text as a second line under its
   // label and draws no line for an undescribed one, so the narrowed
-  // description must survive as the string, or as null when the prompt
+  // description must survive as the string, or as nothing when the prompt
   // gives none.
   check(
-    "an arg's description narrows to its text, or null when the prompt gives none",
-    contract.args.fields[0].description === "the topic" &&
-      contract.args.fields[1].description === null &&
-      contract.args.fields[2].description === null,
+    "an arg's description narrows to its text, or to nothing when the prompt gives none",
+    args.properties.topic.description === "the topic" &&
+      args.properties.deep.description === undefined &&
+      args.properties.limit.description === undefined,
+  );
+  check(
+    "an enum narrows to its allowed values, strings or integers",
+    args.properties.tone.enum?.join(",") === "formal,casual" &&
+      args.properties.opts.properties.depth.enum?.join(",") === "1,2" &&
+      args.properties.opts.properties.depth.enum?.[0] === 1,
+  );
+  check(
+    "an array node narrows its items and keeps its default",
+    args.properties.focus.type === "array" &&
+      args.properties.focus.items?.type === "string" &&
+      JSON.stringify(args.properties.focus.default) === '["methods"]',
+  );
+  check(
+    "a nested object node narrows its own properties",
+    args.properties.opts.type === "object" &&
+      args.properties.opts.additionalProperties === true &&
+      args.properties.opts.required === undefined &&
+      args.properties.opts.properties.depth.type === "integer",
   );
   check(
     "model roles narrow",
@@ -128,7 +167,7 @@ const json = (body, status = 200) => ({
   );
 }
 
-// --- Absent sections narrow to null; implicit args name the prose field ----
+// --- Absent sections narrow to null; the default declaration is one string --
 
 {
   scriptFetch(() =>
@@ -137,14 +176,14 @@ const json = (body, status = 200) => ({
       description: "",
       runvil: null,
       max_tool_iterations: null,
-      input: null,
       output: null,
       uses: [],
       args: {
-        implicit: true,
-        fields: [
-          { name: "prose", type: "string", optional: false, default: null, description: null },
-        ],
+        type: "object",
+        properties: {
+          text: { type: "string", description: "Freeform text for this prompt" },
+        },
+        additionalProperties: false,
       },
       models: [],
     }),
@@ -154,15 +193,14 @@ const json = (body, status = 200) => ({
     "absent sections narrow to null",
     contract.runvil === null &&
       contract.maxToolIterations === null &&
-      contract.input === null &&
       contract.output === null,
   );
   check(
-    "the implicit args declaration names the single prose field",
-    contract.args.implicit === true &&
-      contract.args.fields.length === 1 &&
-      contract.args.fields[0].name === "prose" &&
-      contract.args.fields[0].type === "string",
+    "the default declaration narrows to one optional string named text",
+    Object.keys(contract.args.properties ?? {}).join(",") === "text" &&
+      contract.args.properties.text.type === "string" &&
+      contract.args.properties.text.description === "Freeform text for this prompt" &&
+      contract.args.required === undefined,
   );
 }
 
@@ -211,10 +249,32 @@ const json = (body, status = 200) => ({
     json({
       ...CONTRACT,
       args: {
-        implicit: false,
-        fields: [
-          { name: "when", type: "date", optional: true, default: null, description: null },
-        ],
+        type: "object",
+        properties: { when: { type: "date" } },
+        additionalProperties: false,
+      },
+    }),
+  );
+  let caught = null;
+  try {
+    await fetchPromptContract("p.md", "text");
+  } catch (error) {
+    caught = error;
+  }
+  check(
+    "an unknown type word is a shape failure",
+    caught !== null && caught.code === "unexpected_shape",
+  );
+}
+
+{
+  scriptFetch(() =>
+    json({
+      ...CONTRACT,
+      args: {
+        type: "object",
+        properties: { tags: { type: "array", items: { type: "date" } } },
+        additionalProperties: false,
       },
     }),
   );
@@ -225,7 +285,21 @@ const json = (body, status = 200) => ({
     caught = error;
   }
   check(
-    "an unknown arg type is a shape failure",
+    "an unknown type word under items is a shape failure",
+    caught !== null && caught.code === "unexpected_shape",
+  );
+}
+
+{
+  scriptFetch(() => json({ ...CONTRACT, args: { type: "string" } }));
+  let caught = null;
+  try {
+    await fetchPromptContract("p.md", "text");
+  } catch (error) {
+    caught = error;
+  }
+  check(
+    "a root that is not an object node is a shape failure",
     caught !== null && caught.code === "unexpected_shape",
   );
 }
diff --git a/crates/workshop/ui/test/run-panel.mjs b/crates/workshop/ui/test/run-panel.mjs
index 3543887e..50bd8977 100644
--- a/crates/workshop/ui/test/run-panel.mjs
+++ b/crates/workshop/ui/test/run-panel.mjs
@@ -6,7 +6,11 @@
 // and scripts fetch for /workspace/tree, /workspace/file, /prompts/contract,
 // and /workspace/grant. Covers: the empty open, and the Run tab title for
 // an empty path; a pre-filled open reaching
-// ready with one row per contract item and no tool row; the shimmer class on the tab title
+// ready with one row per contract item and no tool row; one row for each
+// top-level property of the args schema, in the order the server sends them
+// (the required marker, an enum's placeholder, the multiline box for text, a
+// JSON box for an array or object property), and no argument row for a root
+// with no properties; the shimmer class on the tab title
 // in loading and its absence in ready and error, including after the
 // overflow list inits a second tab for the panel; tree dragstart setting
 // application/x-workshop-path and a tree drop loading the prompt; an OS
@@ -19,7 +23,7 @@
 // visible second line (never a tooltip), a boolean arg as a .switch, the
 // screen-reader-only Prompt label tied to its field, Browse... and Choose
 // Prompt as inline links, the drag-over class a droppable drag sets, Choose
-// Prompt and Choose Input opening the form modal with Cancel first, and the
+// Prompt opening the form modal with Cancel first, and the
 // stylesheet's values (the 4% card, the 12px rows, the stacked layout under
 // 500px, the 35px toolbar, the 22px state lines, the footer), read from the
 // source because jsdom applies no layout.
@@ -44,6 +48,7 @@ const bundle = await esbuild.build({
       export { initZones, openInZone, panelIdFor, zoneOfPanel } from "./src/parts/layout/zones.ts";
       export { createPanelComponent, createPanelTabComponent, PANEL_TAB } from "./src/parts/layout/panel-types.ts";
       export { setupWorkspaceDrops } from "./src/parts/workspace/workspace-drops.ts";
+      export { renderContractRows } from "./src/parts/run/run-rows.ts";
     `,
     resolveDir: path.join(uiDir, ".."),
     loader: "ts",
@@ -122,16 +127,25 @@ function contractFor(name) {
     description: `contract for ${name}`,
     runvil: 1,
     max_tool_iterations: 12,
-    input: { path: "in/papers.md", description: "the papers" },
     output: { path: "out/verdicts.md", description: "the verdicts" },
     uses: [{ id: "tools/web" }],
     args: {
-      implicit: false,
-      fields: [
-        { name: "topic", type: "string", optional: false, default: null, description: "the topic" },
-        { name: "deep", type: "boolean", optional: true, default: false, description: null },
-        { name: "limit", type: "integer", optional: true, default: 5, description: null },
-      ],
+      type: "object",
+      properties: {
+        deep: { type: "boolean", default: false },
+        focus: { type: "array", items: { type: "string" }, default: ["methods", "results"] },
+        limit: { type: "integer", default: 5 },
+        opts: {
+          type: "object",
+          properties: { depth: { type: "integer" } },
+          additionalProperties: false,
+        },
+        text: { type: "string", description: "the paper" },
+        tone: { type: "string", enum: ["formal", "casual"] },
+        topic: { type: "string", description: "the topic" },
+      },
+      required: ["topic"],
+      additionalProperties: false,
     },
     models: [
       { label: "strong", min_context: 32000, thinking: true },
@@ -250,6 +264,7 @@ const {
   createPanelTabComponent,
   PANEL_TAB,
   setupWorkspaceDrops,
+  renderContractRows,
 } = await import(pathToFileURL(bundlePath).href);
 
 const failures = [];
@@ -385,19 +400,23 @@ check(
   "the description renders as a read-only row",
   rowText("description")?.textContent.includes("contract for prompt.md") === true,
 );
-const inputField = rowText("input")?.querySelector("input");
-check(
-  "the input row is a text field prefilled from the contract, with Browse",
-  inputField?.value === "in/papers.md" && !!rowText("input")?.querySelector("button"),
-);
 const outputField = rowText("output")?.querySelector("input");
 check("the output row is a prefilled text field", outputField?.value === "out/verdicts.md");
+check(
+  "the rows are one per contract item, the args in the order the server sends them",
+  rows.map((row) => row.querySelector(".ws-run-panel__row-label")?.textContent).join(",") ===
+    "name,description,runvil,output,deep,focus,limit,opts,text,tone,topic,strong,small,fast,max_tool_iterations",
+);
 const topicRow = rowText("topic");
 check(
   "a required arg is marked required",
   topicRow?.querySelector(".ws-run-panel__required") !== null &&
     topicRow?.querySelector("input") !== null,
 );
+check(
+  "only the args the required list names are marked",
+  filledEl.querySelectorAll(".ws-run-panel__required").length === 1,
+);
 const topicDescription = topicRow?.querySelector(".ws-run-panel__row-description");
 check(
   "an arg's description is a visible second line under its label",
@@ -434,6 +453,32 @@ check(
   limitRow?.querySelector('input[type="number"]')?.value === "5" &&
     limitRow.querySelector('input[type="number"]')?.step === "1",
 );
+const toneField = rowText("tone")?.querySelector('input[type="text"]');
+check(
+  "a string arg with an enum lists the allowed values as its placeholder",
+  toneField?.value === "" && toneField.placeholder === "formal | casual",
+);
+check(
+  "a string arg with no enum has no placeholder",
+  topicRow?.querySelector('input[type="text"]')?.placeholder === "",
+);
+const textRow = rowText("text");
+check(
+  "a string arg named text is the multiline box, with its description",
+  textRow?.querySelector("textarea.ws-run-panel__prose") !== null &&
+    textRow.querySelector("input") === null &&
+    textRow.querySelector(".ws-run-panel__row-description")?.textContent === "the paper",
+);
+const focusBox = rowText("focus")?.querySelector("textarea.ws-run-panel__prose");
+check(
+  "an array arg is a JSON box prefilled with its default as compact JSON",
+  focusBox?.value === '["methods","results"]' && focusBox.placeholder === "JSON",
+);
+const optsBox = rowText("opts")?.querySelector("textarea.ws-run-panel__prose");
+check(
+  "an object arg with no default is an empty JSON box",
+  optsBox?.value === "" && optsBox.placeholder === "JSON",
+);
 check(
   "the ready panel renders no tool row",
   rows.length > 0 && filledEl.querySelector(".ws-run-panel__row--tool") === null,
@@ -461,6 +506,27 @@ runButton.click();
 await flush();
 check("the Run button does nothing when clicked", calls.length === fetchesBeforeRun);
 
+// --- A root with no properties draws no argument row ------------------------
+
+// The rows are drawn straight from a narrowed contract, with no window.
+const noArgsRows = window.document.createElement("div");
+renderContractRows(noArgsRows, {
+  name: "noargs",
+  description: "",
+  runvil: null,
+  maxToolIterations: null,
+  output: null,
+  uses: [],
+  args: { type: "object", properties: {}, additionalProperties: false },
+  models: [],
+});
+check(
+  "a root with no properties draws no argument row",
+  [...noArgsRows.querySelectorAll(".ws-run-panel__row-label")]
+    .map((label) => label.textContent)
+    .join(",") === "name,output,max_tool_iterations",
+);
+
 // --- Tree drag: dragstart sets the MIME type; a drop loads the prompt -------
 
 const projectRow = [...window.document.querySelectorAll(".ws-workshop-tree__row")].find(
@@ -698,7 +764,7 @@ check(
     !genRows.some((text) => text.includes("contract for slow.md")),
 );
 
-// --- Dialogs: Choose Prompt and Choose Input open the form modal, Cancel first
+// --- Dialog: Choose Prompt opens the form modal, Cancel first ---------------
 
 // A plain browser has no native picker, so Browse takes the typed-path dialog.
 delete window.__TAURI_INTERNALS__;
@@ -739,28 +805,6 @@ await flush();
 check("Choose closes the dialog and loads the typed prompt", dialogEl.querySelector(".ws-run-choose") === null &&
   [...dialogEl.querySelectorAll(".ws-run-panel__row")].some((row) => row.textContent.includes("typed.md")));
 
-dialogEl.querySelector(".ws-run-panel__input-browse").click();
-await flush();
-const inputDialog = dialogEl.querySelector(".ws-run-input");
-check("the input row's Browse opens Choose Input", inputDialog !== null);
-check(
-  "Choose Input uses the form modal skin with Cancel first",
-  inputDialog?.classList.contains("modal-dialog--form") === true &&
-    dialogButtons(inputDialog).join(",") === "Cancel,Choose",
-);
-const inputPath = inputDialog.querySelector("input");
-inputPath.value = `${ROOT}\\input.md`;
-inputPath.dispatchEvent(new window.Event("input", { bubbles: true }));
-inputDialog.querySelector(".modal-actions button:last-child").click();
-await flush();
-check(
-  "Choose Input fills the input row's field",
-  dialogEl.querySelector(".ws-run-input") === null &&
-    [...dialogEl.querySelectorAll(".ws-run-panel__row")]
-      .find((row) => row.querySelector(".ws-run-panel__row-label")?.textContent === "input")
-      ?.querySelector("input")?.value === `${ROOT}\\input.md`,
-);
-
 brokenEl.querySelector(".ws-run-panel__choose").click();
 await flush();
 const errorChoose = brokenEl.querySelector(".ws-run-choose");