debug-tracer

debug-tracer is an agent for Claude Code from khill1269/servalsheets-v2. It costs 66 tokens per session (1,710 once invoked), scanned A, a copy of debug-tracer, MIT.

A debugging guide for ServalSheets that follows a request through four stages, from MCP input to Google Sheets API calls. ServalSheets is a service that connects an MCP server to Google Sheets.

In plain words
What is it for?
Investigating failing tests, schema mismatches, unexpected behavior, incorrect action dispatch, and errors across the server’s request pipeline.
Why use it?
It helps locate the exact stage where validation, handler logic, response formatting, or an external API call breaks.

Agent for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/khill1269/servalsheets-v2/debug-tracer
Clone the repo
git clone --depth 1 https://github.com/khill1269/servalsheets-v2

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for debug-tracer

README.md
[![agentmods](https://agentmods.dev/badge/agents/khill1269/servalsheets-v2/debug-tracer.svg)](https://agentmods.dev/agents/khill1269/servalsheets-v2/debug-tracer)
Your own site
<a href="https://agentmods.dev/agents/khill1269/servalsheets-v2/debug-tracer"><img src="https://agentmods.dev/badge/agents/khill1269/servalsheets-v2/debug-tracer.svg" alt="Measured on agentmods" height="20"></a>
Per session 66 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,710 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 88% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00066 $0.01710
Opus 5 $0.00033 $0.00855
Sonnet 5 $0.00013 $0.00342
Haiku 4.5 $0.00007 $0.00171

Measured 4d ago against content hash 15e06470a227, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

debug-tracer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

88% identical to debug-tracer — 58 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/agents/debug-tracer.md · 177 lines

How it starts

The opening of the file, as written. The whole thing — 177 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a debug specialist who traces execution through ServalSheets' 4-layer pipeline to find the exact origin of failures.

The 4-Layer Pipeline

Layer 1: Input Validation
  src/mcp/registration/tool-handlers.ts:81-118
  ├── normalizeToolArgs()     — unwraps { request: { action, ...params } } → { action, ...params }
  ├── fast-validators.ts      — 0.1ms pre-validation (spreadsheetId format, required fields)
  └── Zod schema parse        — full validation against src/schemas/{tool}.ts

Layer 2: Handler Execution
  src/handlers/{tool-name}.ts:executeAction()
  ├── switch (action) dispatch to handleXxx()
  └── returns { response: { success: boolean, data?: any } }

Layer 3: Response Building
  src/mcp/registration/tool-handlers.ts:500+
  ├── buildToolResponse()     — converts handler output → MCP CallToolResult format
  └── Output validation       — advisory (logs warnings, does not throw)

Layer 4: Service / Google API
  src/services/google-api.ts via wrapGoogleApi() Proxy
  ├── Auto-retry (3x, exponential backoff + jitter)
  ├── Circuit breaker (opens after 5 failures, half-opens after 30s)
  └── HTTP/2 connection pool

Failure Pattern Reference

Symptom Layer Root Cause Fix
"action is required" 1 Test input not wrapped in legacy envelope Wrap: { request: { action, ...params } }
ZodError: invalid_union 1 Action string not in schema z.enum([...]) Add action to schema enum
ZodError: Required 1 Missing required field in input Add field or make it optional in schema
"Unknown action: X" 2 Handler switch missing case 'X' Add case and handler method
"invalid response structure" 3 Handler returned raw object, not { response: {...} } Fix return value
Circuit breaker OPEN 4 5+ consecutive API failures Check Google API credentials/quota
Silent {} return 2 Default case returns empty object Throw createValidationError(...)
403 PERMISSION_DENIED 4 OAuth scope missing Check src/config/oauth-scopes.ts
429 RESOURCE_EXHAUSTED 4 Quota exceeded Add field masks, use batch operations

Read the full file on GitHub · 177 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 177 lines · 66 tokens per session scan A 15e06470a227

Subscribe to this mod's changes

debug-tracer is an agent published in the GitHub repository khill1269/servalsheets-v2 (0 stars, last pushed 2mo ago), licensed MIT. It adds 66 tokens to every session and 1,710 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to debug-tracer, differing in 58 lines, and is treated as a copy.