diff --git a/scripts/seed-workflow.test.ts b/scripts/seed-workflow.test.ts
new file mode 100644
index 0000000..65caf5c
--- /dev/null
+++ b/scripts/seed-workflow.test.ts
@@ -0,0 +1,145 @@
+import { describe, expect, test } from "bun:test";
+import { readFileSync } from "fs";
+import { join } from "path";
+
+const source = readFileSync(join(import.meta.dir, "seed-workflow.ts"), "utf8");
+
+function extractGeneratedConversationsSendCommands(): string[] {
+  return [...source.matchAll(/^\s+(conversations send .+)$/gm)].map((match) => match[1] ?? "");
+}
+
+function splitShellWords(input: string): string[] {
+  const words: string[] = [];
+  let current = "";
+  let quote: "'" | '"' | null = null;
+  let escaping = false;
+
+  for (const char of input) {
+    if (escaping) {
+      current += char;
+      escaping = false;
+      continue;
+    }
+
+    if (char === "\\") {
+      escaping = true;
+      continue;
+    }
+
+    if (quote) {
+      if (char === quote) {
+        quote = null;
+      } else {
+        current += char;
+      }
+      continue;
+    }
+
+    if (char === "'" || char === '"') {
+      quote = char;
+      continue;
+    }
+
+    if (/\s/.test(char)) {
+      if (current.length > 0) {
+        words.push(current);
+        current = "";
+      }
+      continue;
+    }
+
+    current += char;
+  }
+
+  if (escaping) current += "\\";
+  if (quote) throw new Error(`unterminated ${quote} quote in ${input}`);
+  if (current.length > 0) words.push(current);
+  return words;
+}
+
+function parseSupportedSendFixture(argv: string[]): void {
+  const supportedValueOptions = new Set([
+    "--to",
+    "--from",
+    "--session",
+    "--priority",
+    "--working-dir",
+    "--repository",
+    "--branch",
+    "--metadata",
+    "--channel",
+  ]);
+  const supportedBooleanOptions = new Set(["--blocking", "-j", "--json"]);
+
+  const options = new Map<string, string | boolean>();
+  let message: string | null = null;
+
+  for (let i = 0; i < argv.length; i += 1) {
+    const arg = argv[i];
+    if (arg === undefined) continue;
+
+    if (arg.startsWith("-")) {
+      if (supportedBooleanOptions.has(arg)) {
+        options.set(arg, true);
+        continue;
+      }
+
+      if (!supportedValueOptions.has(arg)) {
+        throw new Error(`unknown option '${arg}'`);
+      }
+
+      const value = argv[i + 1];
+      if (value === undefined || value.startsWith("-")) {
+        throw new Error(`option '${arg}' argument missing`);
+      }
+      options.set(arg, value);
+      i += 1;
+      continue;
+    }
+
+    if (message !== null) {
+      throw new Error(`unexpected argument '${arg}'`);
+    }
+    message = arg;
+  }
+
+  if (!message) {
+    throw new Error("missing required argument 'message'");
+  }
+  if (!options.has("--to") && !options.has("--channel")) {
+    throw new Error("missing required recipient");
+  }
+}
+
+function parseWithSupportedFixture(command: string): void {
+  const argv = splitShellWords(command).map((word) =>
+    word.replaceAll("{{PROJECT_SPACE}}", "project-channel").replaceAll("{{AGENT_NAME}}", "vitruvius"),
+  );
+  expect(argv.slice(0, 2)).toEqual(["conversations", "send"]);
+  parseSupportedSendFixture(argv.slice(2));
+}
+
+describe("agent workflow conversations send contract", () => {
+  test("generated commands use the positional message contract accepted by the supported parser fixture", () => {
+    const commands = extractGeneratedConversationsSendCommands();
+
+    expect(commands).toHaveLength(2);
+    for (const command of commands) {
+      expect(command).toContain('conversations send "');
+      expect(command).toContain("--channel {{PROJECT_SPACE}}");
+      expect(command).toContain("--from {{AGENT_NAME}}");
+      parseWithSupportedFixture(command);
+    }
+  });
+
+  test("generated commands do not emit stale --content or --space send flags", () => {
+    const commands = extractGeneratedConversationsSendCommands();
+
+    expect(commands.join("\n")).not.toContain("--content");
+    expect(commands.join("\n")).not.toContain("--space");
+  });
+
+  test("the supported parser fixture rejects the stale --content and --space form", () => {
+    expect(() => parseWithSupportedFixture('conversations send --space project-channel --content "shipped X"')).toThrow();
+  });
+});
diff --git a/scripts/seed-workflow.ts b/scripts/seed-workflow.ts
index 054e6ec..405f465 100644
--- a/scripts/seed-workflow.ts
+++ b/scripts/seed-workflow.ts
@@ -42,7 +42,7 @@ const WORKFLOW_TEMPLATE = `# Agent Workflow — @hasna Ecosystem Standard
   conversations heartbeat --name {{AGENT_NAME}} --status "working on X"
 
 - Communicate decisions
-  conversations send --space {{PROJECT_SPACE}} --content "shipped X"
+  conversations send "shipped X" --channel {{PROJECT_SPACE}} --from {{AGENT_NAME}}
 
 - Track progress
   todos update <task-id> --status in_progress
@@ -58,7 +58,7 @@ const WORKFLOW_TEMPLATE = `# Agent Workflow — @hasna Ecosystem Standard
    mementos save --key "session-summary" --value "what was accomplished" --scope shared --importance 8
 
 3. Post completion to space
-   conversations send --space {{PROJECT_SPACE}} --content "shipped: description of changes"
+   conversations send "shipped: description of changes" --channel {{PROJECT_SPACE}} --from {{AGENT_NAME}}
 
 4. Clean up
    attachments health-check --fix   # regenerate any expired evidence links