perstack-ai · FL4TLiN3 · Feb 19, 2026 · Feb 18, 2026 · Feb 18, 2026 · Feb 18, 2026
diff --git a/.changeset/strict-attempt-completion-schema.md b/.changeset/strict-attempt-completion-schema.md
@@ -0,0 +1,16 @@
+---
+"@perstack/base": patch
+"@perstack/runtime": patch
+"@perstack/core": patch
+"@perstack/react": patch
+---
+
+fix: add result param to attemptCompletion and remove GeneratingRunResult
+
+- Add optional `result` string parameter to attemptCompletion tool schema so the LLM
+  can provide its final response text directly in the tool call
+- Complete runs directly from CallingMcpTools when attemptCompletion succeeds, eliminating
+  the extra LLM round-trip in GeneratingRunResult
+- Remove GeneratingRunResult state, its transitions, and the attemptCompletion event type
+- Remove dead attemptCompletion event handling code from React event-to-activity utils
+- Update E2E expert instructions to pass result via attemptCompletion args
diff --git a/apps/base/src/tools/attempt-completion.ts b/apps/base/src/tools/attempt-completion.ts
@@ -1,4 +1,5 @@
 import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"
+import { z } from "zod"
 import { errorToolResult, successToolResult } from "../lib/tool-result.js"
 import { getRemainingTodos } from "./todo.js"
 
@@ -19,8 +20,9 @@ export function registerAttemptCompletion(server: McpServer) {
     "attemptCompletion",
     {
       title: "Attempt completion",
-      description: "Signal task completion. Validates all todos are complete before ending.",
-      inputSchema: {},
+      description:
+        "Signal task completion. Provide a result parameter with your final response text. Validates all todos are complete before ending.",
+      inputSchema: z.object({ result: z.string().optional() }).strict(),
     },
     async () => {
       try {

diff --git a/e2e/experts/bundled-base.toml b/e2e/experts/bundled-base.toml
@@ -13,7 +13,7 @@ envPath = [".env", ".env.local"]
 version = "1.0.0"
 description = "E2E test expert for bundled base with InMemoryTransport"
 instruction = """
-Call readTextFile on "perstack.toml" and then call attemptCompletion with result "OK"
+Call readTextFile on "perstack.toml", then call attemptCompletion.
 """
 
 [experts."e2e-bundled-base".skills."@perstack/base"]

diff --git a/e2e/experts/cli-commands.toml b/e2e/experts/cli-commands.toml
@@ -9,7 +9,7 @@ envPath = [".env", ".env.local"]
 version = "1.0.0"
 description = "E2E test expert for CLI publish command validation"
 instruction = """
-Call attemptCompletion with result "OK"
+Call attemptCompletion.
 """
 
 [experts."e2e-publish-test".skills."@perstack/base"]
@@ -22,7 +22,7 @@ pick = ["attemptCompletion"]
 version = "1.0.0"
 description = "E2E test expert for CLI log command validation"
 instruction = """
-Call attemptCompletion with result "OK"
+Call attemptCompletion.
 """
 
 [experts."e2e-cli-simple".skills."@perstack/base"]

diff --git a/e2e/experts/continue-resume.toml b/e2e/experts/continue-resume.toml
@@ -10,7 +10,7 @@ version = "1.0.0"
 description = "E2E test expert for continue functionality"
 instruction = """
 1. Call askUser with question "confirm?"
-2. After user responds, call attemptCompletion with result "OK"
+2. After user responds, call attemptCompletion
 """
 
 [experts."e2e-continue".skills."user-input"]
@@ -34,7 +34,7 @@ description = "E2E test expert for resume-from functionality"
 instruction = """
 1. Call think with thought "processing"
 2. Call askUser with question "confirm?"
-3. After user responds, call attemptCompletion with result "OK"
+3. After user responds, call attemptCompletion
 """
 
 [experts."e2e-resume".skills."user-input"]

diff --git a/e2e/experts/delegate-chain.toml b/e2e/experts/delegate-chain.toml
@@ -10,7 +10,7 @@ version = "1.0.0"
 description = "E2E test expert for delegate chain"
 instruction = """
 1. Delegate to "e2e-delegate-level1" with "test"
-2. When done, call attemptCompletion with result "OK"
+2. When done, call attemptCompletion
 """
 delegates = ["e2e-delegate-level1"]
 
@@ -25,7 +25,7 @@ version = "1.0.0"
 description = "First level delegate expert"
 instruction = """
 1. Delegate to "e2e-delegate-level2" with "test"
-2. When done, call attemptCompletion with result "OK"
+2. When done, call attemptCompletion
 """
 delegates = ["e2e-delegate-level2"]
 
@@ -39,7 +39,7 @@ pick = ["attemptCompletion"]
 version = "1.0.0"
 description = "Second level delegate expert"
 instruction = """
-Call attemptCompletion with result "OK"
+Call attemptCompletion.
 """
 
 [experts."e2e-delegate-level2".skills."@perstack/base"]

diff --git a/e2e/experts/error-handling.toml b/e2e/experts/error-handling.toml
@@ -10,7 +10,7 @@ version = "1.0.0"
 description = "E2E test expert for tool error recovery"
 instruction = """
 1. Use readTextFile with the exact path given by user
-2. Call attemptCompletion reporting: success/error + content or error message
+2. Call attemptCompletion
 """
 
 [experts."e2e-tool-error-recovery".skills."@perstack/base"]

diff --git a/e2e/experts/errors.toml b/e2e/experts/errors.toml
@@ -9,7 +9,7 @@ envPath = [".env", ".env.local"]
 version = "1.0.0"
 description = "E2E test expert with broken MCP skill"
 instruction = """
-Call attemptCompletion with result "OK"
+Call attemptCompletion.
 """
 
 [experts."e2e-mcp-error".skills."broken-skill"]
@@ -27,7 +27,7 @@ pick = ["attemptCompletion"]
 version = "1.0.0"
 description = "E2E test expert for invalid provider testing"
 instruction = """
-Call attemptCompletion with result "OK"
+Call attemptCompletion.
 """
 
 [experts."e2e-invalid-provider".skills."@perstack/base"]

diff --git a/e2e/experts/global-runtime.toml b/e2e/experts/global-runtime.toml
@@ -9,7 +9,7 @@ envPath = [".env", ".env.local"]
 version = "1.0.0"
 description = "E2E test expert for global runtime configuration"
 instruction = """
-Call attemptCompletion with result "OK"
+Call attemptCompletion.
 """
 
 [experts."e2e-global-runtime".skills."@perstack/base"]

diff --git a/e2e/experts/lockfile.toml b/e2e/experts/lockfile.toml
@@ -12,7 +12,7 @@ envPath = [".env", ".env.local"]
 version = "1.0.0"
 description = "E2E test expert for lockfile functionality"
 instruction = """
-Call readTextFile on "perstack.toml" and then call attemptCompletion with result "lockfile-test-ok"
+Call readTextFile on "perstack.toml", then call attemptCompletion.
 """
 
 [experts."e2e-lockfile".skills."@perstack/base"]

diff --git a/e2e/experts/mixed-tools.toml b/e2e/experts/mixed-tools.toml
@@ -42,7 +42,7 @@ pick = ["attemptCompletion", "think"]
 version = "1.0.0"
 description = "E2E test helper expert"
 instruction = """
-Call attemptCompletion with result "OK"
+Call attemptCompletion.
 """
 
 [experts."e2e-helper".skills."@perstack/base"]

diff --git a/e2e/experts/multi-modal.toml b/e2e/experts/multi-modal.toml
@@ -10,7 +10,7 @@ version = "1.0.0"
 description = "E2E test expert for PDF file reading"
 instruction = """
 1. Use readPdfFile to read the PDF at the specified path
-2. Call attemptCompletion with a brief summary of the content
+2. Call attemptCompletion with a brief summary of the content as the result
 """
 
 [experts."e2e-pdf-reader".skills."@perstack/base"]
@@ -24,7 +24,7 @@ version = "1.0.0"
 description = "E2E test expert for image file reading"
 instruction = """
 1. Use readImageFile to read the image at the specified path
-2. Call attemptCompletion with a brief description of the image
+2. Call attemptCompletion with a brief description of the image as the result
 """
 
 [experts."e2e-image-reader".skills."@perstack/base"]

diff --git a/e2e/experts/parallel-delegate.toml b/e2e/experts/parallel-delegate.toml
@@ -10,7 +10,7 @@ version = "1.0.0"
 description = "E2E test expert for parallel delegation"
 instruction = """
 1. In ONE response, delegate to BOTH "e2e-delegate-math" and "e2e-delegate-text" with "test"
-2. When both return, call attemptCompletion with result "OK"
+2. When both return, call attemptCompletion
 """
 delegates = ["e2e-delegate-math", "e2e-delegate-text"]
 
@@ -24,7 +24,7 @@ pick = ["attemptCompletion", "think"]
 version = "1.0.0"
 description = "Math delegate expert"
 instruction = """
-Call attemptCompletion with result "Math result: 5"
+Call attemptCompletion.
 """
 
 [experts."e2e-delegate-math".skills."@perstack/base"]
@@ -37,7 +37,7 @@ pick = ["attemptCompletion"]
 version = "1.0.0"
 description = "Text processing delegate expert"
 instruction = """
-Call attemptCompletion with result "Text result: olleh"
+Call attemptCompletion.
 """
 
 [experts."e2e-delegate-text".skills."@perstack/base"]

diff --git a/e2e/experts/reasoning-budget.toml b/e2e/experts/reasoning-budget.toml
@@ -12,7 +12,7 @@ version = "1.0.0"
 description = "E2E test expert for Anthropic reasoning with minimal budget"
 instruction = """
 Solve this step by step: What is 23 * 47?
-Show your reasoning, then call attemptCompletion with the answer.
+Show your reasoning, then call attemptCompletion.
 """
 
 [experts."e2e-reasoning-anthropic-minimal".skills."@perstack/base"]
@@ -26,7 +26,7 @@ version = "1.0.0"
 description = "E2E test expert for Anthropic reasoning with low budget"
 instruction = """
 Solve this step by step: What is 23 * 47?
-Show your reasoning, then call attemptCompletion with the answer.
+Show your reasoning, then call attemptCompletion.
 """
 
 [experts."e2e-reasoning-anthropic-low".skills."@perstack/base"]
@@ -40,7 +40,7 @@ version = "1.0.0"
 description = "E2E test expert for Anthropic reasoning with medium budget"
 instruction = """
 Solve this step by step: What is 23 * 47?
-Show your reasoning, then call attemptCompletion with the answer.
+Show your reasoning, then call attemptCompletion.
 """
 
 [experts."e2e-reasoning-anthropic-medium".skills."@perstack/base"]
@@ -54,7 +54,7 @@ version = "1.0.0"
 description = "E2E test expert for Anthropic reasoning with high budget"
 instruction = """
 Solve this step by step: What is 23 * 47?
-Show your reasoning, then call attemptCompletion with the answer.
+Show your reasoning, then call attemptCompletion.
 """
 
 [experts."e2e-reasoning-anthropic-high".skills."@perstack/base"]
@@ -72,7 +72,7 @@ version = "1.0.0"
 description = "E2E test expert for OpenAI reasoning with minimal budget"
 instruction = """
 Solve this step by step: What is 23 * 47?
-Show your reasoning, then call attemptCompletion with the answer.
+Show your reasoning, then call attemptCompletion.
 """
 
 [experts."e2e-reasoning-openai-minimal".skills."@perstack/base"]
@@ -86,7 +86,7 @@ version = "1.0.0"
 description = "E2E test expert for OpenAI reasoning with low budget"
 instruction = """
 Solve this step by step: What is 23 * 47?
-Show your reasoning, then call attemptCompletion with the answer.
+Show your reasoning, then call attemptCompletion.
 """
 
 [experts."e2e-reasoning-openai-low".skills."@perstack/base"]
@@ -100,7 +100,7 @@ version = "1.0.0"
 description = "E2E test expert for OpenAI reasoning with medium budget"
 instruction = """
 Solve this step by step: What is 23 * 47?
-Show your reasoning, then call attemptCompletion with the answer.
+Show your reasoning, then call attemptCompletion.
 """
 
 [experts."e2e-reasoning-openai-medium".skills."@perstack/base"]
@@ -114,7 +114,7 @@ version = "1.0.0"
 description = "E2E test expert for OpenAI reasoning with high budget"
 instruction = """
 Solve this step by step: What is 23 * 47?
-Show your reasoning, then call attemptCompletion with the answer.
+Show your reasoning, then call attemptCompletion.
 """
 
 [experts."e2e-reasoning-openai-high".skills."@perstack/base"]
@@ -132,7 +132,7 @@ version = "1.0.0"
 description = "E2E test expert for Google reasoning with minimal budget"
 instruction = """
 Solve this step by step: What is 23 * 47?
-Show your reasoning, then call attemptCompletion with the answer.
+Show your reasoning, then call attemptCompletion.
 """
 
 [experts."e2e-reasoning-google-minimal".skills."@perstack/base"]
@@ -146,7 +146,7 @@ version = "1.0.0"
 description = "E2E test expert for Google reasoning with low budget"
 instruction = """
 Solve this step by step: What is 23 * 47?
-Show your reasoning, then call attemptCompletion with the answer.
+Show your reasoning, then call attemptCompletion.
 """
 
 [experts."e2e-reasoning-google-low".skills."@perstack/base"]
@@ -160,7 +160,7 @@ version = "1.0.0"
 description = "E2E test expert for Google reasoning with medium budget"
 instruction = """
 Solve this step by step: What is 23 * 47?
-Show your reasoning, then call attemptCompletion with the answer.
+Show your reasoning, then call attemptCompletion.
 """
 
 [experts."e2e-reasoning-google-medium".skills."@perstack/base"]
@@ -174,7 +174,7 @@ version = "1.0.0"
 description = "E2E test expert for Google reasoning with high budget"
 instruction = """
 Solve this step by step: What is 23 * 47?
-Show your reasoning, then call attemptCompletion with the answer.
+Show your reasoning, then call attemptCompletion.
 """
 
 [experts."e2e-reasoning-google-high".skills."@perstack/base"]

diff --git a/e2e/experts/runtime-version-future.toml b/e2e/experts/runtime-version-future.toml
@@ -9,7 +9,7 @@ envPath = [".env", ".env.local"]
 [experts."e2e-runtime-future"]
 version = "1.0.0"
 minRuntimeVersion = "v99.0"
-instruction = "Call attemptCompletion with result 'OK'"
+instruction = "Call attemptCompletion."
 
 [experts."e2e-runtime-future".skills."@perstack/base"]
 type = "mcpStdioSkill"
@@ -23,7 +23,7 @@ version = "1.0.0"
 minRuntimeVersion = "v1.0"
 instruction = """
 1. Delegate to "e2e-runtime-future" with "test"
-2. When done, call attemptCompletion with result "OK"
+2. When done, call attemptCompletion
 """
 delegates = ["e2e-runtime-future"]
 

diff --git a/e2e/experts/runtime-version.toml b/e2e/experts/runtime-version.toml
@@ -9,7 +9,7 @@ envPath = [".env", ".env.local"]
 [experts."e2e-runtime-v1"]
 version = "1.0.0"
 minRuntimeVersion = "v1.0"
-instruction = "Call attemptCompletion with result 'OK'"
+instruction = "Call attemptCompletion."
 
 [experts."e2e-runtime-v1".skills."@perstack/base"]
 type = "mcpStdioSkill"
@@ -20,7 +20,7 @@ pick = ["attemptCompletion"]
 # Expert without minRuntimeVersion (default)
 [experts."e2e-runtime-default"]
 version = "1.0.0"
-instruction = "Call attemptCompletion with result 'OK'"
+instruction = "Call attemptCompletion."
 
 [experts."e2e-runtime-default".skills."@perstack/base"]
 type = "mcpStdioSkill"
@@ -34,7 +34,7 @@ version = "1.0.0"
 minRuntimeVersion = "v1.0"
 instruction = """
 1. Delegate to "e2e-runtime-chain-ok-l1" with "test"
-2. When done, call attemptCompletion with result "OK"
+2. When done, call attemptCompletion
 """
 delegates = ["e2e-runtime-chain-ok-l1"]
 
@@ -49,7 +49,7 @@ version = "1.0.0"
 minRuntimeVersion = "v1.0"
 instruction = """
 1. Delegate to "e2e-runtime-chain-ok-l2" with "test"
-2. When done, call attemptCompletion with result "OK"
+2. When done, call attemptCompletion
 """
 delegates = ["e2e-runtime-chain-ok-l2"]
 
@@ -62,7 +62,7 @@ pick = ["attemptCompletion"]
 [experts."e2e-runtime-chain-ok-l2"]
 version = "1.0.0"
 minRuntimeVersion = "v1.0"
-instruction = "Call attemptCompletion with result 'OK'"
+instruction = "Call attemptCompletion."
 
 [experts."e2e-runtime-chain-ok-l2".skills."@perstack/base"]
 type = "mcpStdioSkill"