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fix(pi-claude-cli): unblock parameterless MCP tool calls in triage

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Triage with claude-sonnet-4-6 via pi-claude-cli kept looping on
fn_review_spec calls that were rejected by pi's validator with
"root: must be object". Parameterless MCP tools (schema
{type:"object", properties:{}}) emit zero input_json_delta events,
so partialJson stayed "" and the catch fell through to
finalArgs = "" — a string, which TypeBox's Type.Object({}) rightly
refuses. Default empty partialJson to {} so the call lands.

Also:
- Add a 2-step reminder loop in triage before swapping to the
  fallback planning model — primary models that wrote PROMPT.md
  but forgot fn_review_spec recover from a nudge, no need to pay
  the cold-start tax of a new triage on a different model.
- Inject @runfusion/fusion's own pi extension into dashboard/
  daemon/serve sessions and propagate the path to createFnAgent
  via setHostExtensionPaths so fn_* tools register globally
  without requiring `pi install npm:@runfusion/fusion`.
- Drop the "historical" qualifier from replayed tool labels —
  Claude was reading "TOOL RESULT (historical Read):" as
  "previous session, ignore" and looping on verification.
- Remove subprocess-lifecycle stderr debug logs that landed for
  hang diagnosis — root cause is fixed, the noise can go.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
gsxdsm
2026-04-26 00:00:49 -07:00
parent 15149905fd
commit c1a2b6edd7
13 changed files with 269 additions and 89 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
packages/pi-claude-cli/src/__tests__/event-bridge.test.ts
View File

@@ -444,6 +444,40 @@ describe("createEventBridge", () => {
expect(event.toolCall.arguments).toEqual({ path: "/foo.ts" });
});
it("emits {} for parameterless MCP tool calls (no input_json_delta)", () => {
// Parameterless MCP tools (e.g. fn_review_spec, schema
// {type:"object", properties:{}}) emit ZERO input_json_delta events.
// Without the empty-partialJson guard, finalArgs would fall through to
// the raw-string fallback ("") and pi's TypeBox validator would reject
// the call with "Validation failed for tool ...: root: must be object".
const bridge = createBridgeWithStart();
bridge.handleEvent({
type: "content_block_start",
index: 0,
content_block: {
type: "tool_use",
id: "toolu_01XYZ",
name: "mcp__custom-tools__fn_review_spec",
},
});
// No content_block_delta with input_json_delta — Claude emits none for
// parameterless tools.
stream.push.mockClear();
stream.events.length = 0;
bridge.handleEvent({
type: "content_block_stop",
index: 0,
});
expect(stream.push).toHaveBeenCalledTimes(1);
const event = stream.events[0] as any;
expect(event.type).toBe("toolcall_end");
expect(event.toolCall.arguments).toEqual({});
// The MCP prefix should be stripped: pi sees the bare tool name.
expect(event.toolCall.name).toBe("fn_review_spec");
});
it("tracks multiple tool_use blocks independently by Claude event.index", () => {
const bridge = createBridgeWithStart();

21
packages/pi-claude-cli/src/__tests__/prompt-builder.test.ts
View File

@@ -21,7 +21,7 @@ describe("buildPrompt", () => {
expect(buildPrompt(context)).toBe("ASSISTANT:\nHi there");
});
it("produces 'TOOL RESULT (historical {claudeName}):\\n{content}' for a tool result message", () => {
it("produces 'TOOL RESULT ({claudeName}):\\n{content}' for a tool result message", () => {
const context = {
messages: [
{
@@ -33,7 +33,7 @@ describe("buildPrompt", () => {
} as unknown as any;
// Pi tool name "read" should be mapped to Claude name "Read" in the label
expect(buildPrompt(context)).toBe(
"TOOL RESULT (historical Read):\nfile contents here",
"TOOL RESULT (Read):\nfile contents here",
);
});
@@ -57,7 +57,7 @@ describe("buildPrompt", () => {
"What is in file.ts?",
"ASSISTANT:",
"Let me read that file.",
"TOOL RESULT (historical Read):",
"TOOL RESULT (Read):",
"export const x = 1;",
"USER:",
"Now explain it.",
@@ -109,7 +109,7 @@ describe("buildPrompt", () => {
// Tool name should be mapped from pi "read" to Claude "Read"
// Arg "path" should be mapped from pi format to Claude "file_path"
expect(result).toContain(
'Historical tool call (non-executable): Read args={"file_path":"/file.ts"}',
'[Prior tool call — already executed; result follows in TOOL RESULT (Read):] args={"file_path":"/file.ts"}',
);
});
@@ -158,7 +158,7 @@ describe("buildPrompt", () => {
const result = buildPrompt(context);
// Pi "bash" maps to Claude "Bash"
expect(result).toContain(
"Historical tool call (non-executable): Bash args={}",
"[Prior tool call — already executed; result follows in TOOL RESULT (Bash):] args={}",
);
});
@@ -177,7 +177,7 @@ describe("buildPrompt", () => {
} as unknown as any;
const result = buildPrompt(context);
expect(result).toBe("TOOL RESULT (historical Bash):\nline 1\nline 2");
expect(result).toBe("TOOL RESULT (Bash):\nline 1\nline 2");
});
describe("tool name and argument reverse mapping", () => {
@@ -237,7 +237,7 @@ describe("buildPrompt", () => {
} as unknown as any;
const result = buildPrompt(context);
expect(result).toContain("TOOL RESULT (historical Read):");
expect(result).toContain("TOOL RESULT (Read):");
});
it("prefixes custom (non-built-in) tool names with MCP prefix", () => {
@@ -281,7 +281,8 @@ describe("buildPrompt", () => {
const result = buildPrompt(context);
// String arguments should be serialized as JSON string
expect(result).toContain('Read args="raw string args"');
expect(result).toContain('TOOL RESULT (Read):');
expect(result).toContain('args="raw string args"');
});
});
});
@@ -688,7 +689,7 @@ describe("custom tool history replay", () => {
} as unknown as any;
const result = buildPrompt(context);
expect(result).toContain("TOOL RESULT (historical Read):");
expect(result).toContain("TOOL RESULT (Read):");
expect(result).not.toContain("mcp__custom-tools__");
});
@@ -1019,7 +1020,7 @@ describe("buildResumePrompt", () => {
],
};
const result = buildResumePrompt(context) as string;
expect(result).toContain("TOOL RESULT (historical Read):");
expect(result).toContain("TOOL RESULT (Read):");
expect(result).toContain("file contents here");
expect(result).toContain("Now explain it");
});

23
packages/pi-claude-cli/src/event-bridge.ts
View File

@@ -323,13 +323,24 @@ export function createEventBridge(
partial: output,
});
} else if (block.type === "tool_use") {
// Final JSON parse with fallback to raw string
// Final JSON parse with fallback to raw string.
// Special case: parameterless MCP tools (e.g. fn_review_spec, schema
// `{type:"object", properties:{}}`) emit ZERO input_json_delta events,
// so `partialJson` stays "". Without this guard we'd JSON.parse("")
// → throw → fall through to `finalArgs = ""` (raw string), and pi's
// TypeBox validator then rejects with "root: must be object" because
// an empty string is not an object. Default to `{}` so the call lands.
let finalArgs: Record<string, unknown> | string;
try {
const parsed = JSON.parse(block.partialJson);
finalArgs = translateClaudeArgsToPi(block.claudeName, parsed);
} catch {
finalArgs = block.partialJson;
const trimmedJson = block.partialJson.trim();
if (trimmedJson === "") {
finalArgs = {};
} else {
try {
const parsed = JSON.parse(trimmedJson);
finalArgs = translateClaudeArgsToPi(block.claudeName, parsed);
} catch {
finalArgs = block.partialJson;
}
}
// Update output.content with final arguments

24
packages/pi-claude-cli/src/prompt-builder.ts
View File

@@ -62,7 +62,7 @@ type AnthropicContentBlock =
* Each message is labeled with its role:
* - USER: for user messages
* - ASSISTANT: for assistant messages
* - TOOL RESULT (historical {toolName}): for tool result messages
* - TOOL RESULT ({toolName}): for tool result messages
*/
/** Module-level counter for placeholder images, reset per buildPrompt call. */
let placeholderImageCount = 0;
@@ -213,7 +213,7 @@ export function buildResumePrompt(context: PiContext): string | AnthropicContent
const claudeToolName = msg.toolName
? mapPiToolNameToClaude(msg.toolName)
: "unknown";
parts.push(`TOOL RESULT (historical ${claudeToolName}):`);
parts.push(`TOOL RESULT (${claudeToolName}):`);
}
parts.push(toolResultContentToText(msg.content));
} else if (msg.role === "user") {
@@ -283,7 +283,7 @@ export function buildPrompt(context: PiContext): string | AnthropicContentBlock[
const claudeToolName = message.toolName
? mapPiToolNameToClaude(message.toolName)
: "unknown";
historyParts.push(`TOOL RESULT (historical ${claudeToolName}):`);
historyParts.push(`TOOL RESULT (${claudeToolName}):`);
}
// Extract text portion of tool result
historyParts.push(toolResultContentToText(message.content));
@@ -347,7 +347,7 @@ export function buildPrompt(context: PiContext): string | AnthropicContentBlock[
const claudeToolName = message.toolName
? mapPiToolNameToClaude(message.toolName)
: "unknown";
parts.push(`TOOL RESULT (historical ${claudeToolName}):`);
parts.push(`TOOL RESULT (${claudeToolName}):`);
}
parts.push(toolResultContentToText(message.content));
}
@@ -451,8 +451,6 @@ function rewriteCustomToolReferences(
}
let result = prompt;
let totalRewrites = 0;
const rewritten: string[] = [];
for (const tool of tools) {
if (BUILT_IN_PI_TOOLS.has(tool.name)) continue;
// \b doesn't treat `_` as a word boundary the way we want here, so anchor
@@ -464,19 +462,7 @@ function rewriteCustomToolReferences(
`(?<![A-Za-z0-9_])(?<!mcp__custom-tools__)${escaped}(?![A-Za-z0-9_])`,
"g",
);
const before = result;
result = result.replace(pattern, `mcp__custom-tools__${tool.name}`);
if (result !== before) {
const matches = before.match(pattern);
const count = matches?.length ?? 0;
totalRewrites += count;
rewritten.push(`${tool.name}×${count}`);
}
}
if (totalRewrites > 0) {
console.error(
`[pi-claude-cli] system prompt: rewrote ${totalRewrites} custom tool ref(s) [${rewritten.join(", ")}]`,
);
}
return result;
}
@@ -580,7 +566,7 @@ function contentToText(content: string | unknown[]): string {
: typeof rawArgs === "string"
? JSON.stringify(rawArgs)
: "{}";
return `Historical tool call (non-executable): ${claudeName} args=${argsStr}`;
return `[Prior tool call — already executed; result follows in TOOL RESULT (${claudeName}):] args=${argsStr}`;
}
// Unknown block types are represented as a placeholder
return `[${String(block.type)}]`;

48
packages/pi-claude-cli/src/provider.ts
View File

@@ -136,11 +136,6 @@ export function streamViaCli(
});
const getStderr = captureStderr(proc);
const spawnTime = Date.now();
const procPid = proc.pid;
const traceMode = resumeSessionId ? "resume" : "new";
console.error(
`[pi-claude-cli] spawn pid=${procPid} model=${model.id} mode=${traceMode} effort=${effort ?? "default"} promptLen=${typeof prompt === "string" ? prompt.length : 0} systemPromptLen=${systemPrompt?.length ?? 0} mcp=${options?.mcpConfigPath ? "yes" : "no"}`,
);
// Register in global process registry for teardown cleanup
registerProcess(proc);
@@ -231,12 +226,8 @@ export function streamViaCli(
});
// Handle subprocess close -- surface crashes with stderr and exit code
proc.on("close", (code: number | null, signal: string | null) => {
proc.on("close", (code: number | null, _signal: string | null) => {
clearTimeout(inactivityTimer);
const elapsedMs = Date.now() - spawnTime;
console.error(
`[pi-claude-cli] close pid=${procPid} code=${code ?? "null"} signal=${signal ?? "null"} elapsedMs=${elapsedMs} broken=${broken}`,
);
if (broken) return; // Break-early kill, expected
if (code !== 0 && code !== null) {
const stderr = getStderr();
@@ -250,9 +241,6 @@ export function streamViaCli(
// Start inactivity timer after writing user message
resetInactivityTimer();
let firstLineLoggedAt = 0;
let lineCount = 0;
// Process NDJSON lines from stdout using event-based callback
// NOTE: Using 'line' event instead of `for await` because the async
// iterator batches lines, breaking real-time streaming to pi.
@@ -261,36 +249,10 @@ export function streamViaCli(
// Reset inactivity timer on each line of output
resetInactivityTimer();
lineCount++;
if (lineCount === 1) {
firstLineLoggedAt = Date.now();
console.error(
`[pi-claude-cli] first-stdout-line pid=${procPid} afterMs=${firstLineLoggedAt - spawnTime}`,
);
}
const msg = parseLine(line);
if (!msg) return;
// Log init system event so we can see MCP server status / model on stderr
if (
msg.type === "system" &&
(msg as { subtype?: string }).subtype === "init"
) {
const init = msg as unknown as {
session_id?: string;
mcp_servers?: Array<{ name: string; status: string }>;
model?: string;
permissionMode?: string;
};
const mcps = (init.mcp_servers ?? [])
.map((s) => `${s.name}=${s.status}`)
.join(",");
console.error(
`[pi-claude-cli] init pid=${procPid} session=${init.session_id ?? "?"} model=${init.model ?? "?"} permissionMode=${init.permissionMode ?? "?"} mcp=[${mcps}]`,
);
}
if (msg.type === "stream_event") {
// Only forward top-level events to pi's event bridge.
// Sub-agent events (parent_tool_use_id !== null) are internal to the CLI.
@@ -306,11 +268,6 @@ export function streamViaCli(
msg.event.content_block?.type === "tool_use"
) {
const toolName = msg.event.content_block.name;
if (toolName) {
console.error(
`[pi-claude-cli] tool_use pid=${procPid} name=${toolName} piKnown=${isPiKnownClaudeTool(toolName)}`,
);
}
if (toolName && isPiKnownClaudeTool(toolName)) {
// Built-in tool (Read/Write/etc.) OR custom MCP tool (mcp__custom-tools__*)
// Internal Claude Code tools (ToolSearch, Task, etc.) are excluded
@@ -325,9 +282,6 @@ export function streamViaCli(
msg.event.type === "message_stop" &&
sawBuiltInOrCustomTool
) {
console.error(
`[pi-claude-cli] break-early pid=${procPid} elapsedMs=${Date.now() - spawnTime} lines=${lineCount}`,
);
broken = true; // Set guard BEFORE rl.close() to prevent buffered lines
clearTimeout(inactivityTimer);
// Pi will execute these tools. Kill subprocess to prevent CLI from executing them.