agent-debugger

Runbook-driven backend incident investigation for AI agents.

Status: early open-source MVP.

This repository was inspired by a real internal AI troubleshooting and self-healing workflow. The original production DAG, permissions, and observability plumbing are private and are not reproduced here. This repo focuses on the reusable layer: runbooks, evidence normalization, decision logic, and an MCP entrypoint.

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Does This Sound Familiar?

Many online incidents are not hard because they are unique. They are hard because engineers keep replaying the same investigation sequence by hand:

• Compare actual behavior with the expected result.
• Check whether Redis is already wrong.
• Check whether the database source of truth is wrong.
• Check the trace to see where the workflow stopped.
• Decide whether the issue is stale cache, missing side effects, or abnormal persisted state.

Example:

• A detail page returns the wrong asset state.
• The expected investigation order is stable: inspect cache, inspect DB, inspect trace, inspect external dependencies.
• The useful input for the agent is also stable: trace_id, expected result, actual result.

agent-debugger exists for that pattern. It turns repeated troubleshooting habits into executable runbooks so an agent can gather evidence in order instead of guessing freely.

What This Repo Actually Implements

• A runbook selector that scores incident patterns and picks the best-matching investigation path.
• An executor that calls adapters in a fixed order defined by the runbook.
• Evidence normalization so tool output becomes compact, structured findings instead of raw payload dumps.
• A decision engine that maps evidence combinations to conclusions and next actions.
• An MCP server entrypoint so the investigation flow can be exposed to AI tools.

5-Minute Demo

The zero-config path is the fastest way to understand the project. It uses replayable fixtures and does not require Langfuse, Postgres, or Redis credentials.

Requirements:

• Node.js >= 18.17
• pnpm

Run:

pnpm install
pnpm demo
pnpm benchmark
pnpm check

What you get:

• A runnable incident walkthrough from fixture input to structured report.
• A benchmark over the built-in replay cases.
• A metadata consistency check for runbooks, adapters, and evidence policies.

Important:

• pnpm demo and pnpm benchmark validate replayable investigation cases.
• They are meant to prove the investigation model and repository structure, not to claim full production integration coverage.

A Concrete Demo Scenario

The default demo replays this kind of incident:

• Actual: an order was created, but the downstream task was never generated.
• Expected: a task record should exist after order creation.
• Investigation order: trace -> persistence -> idempotency/cache.

The output shows:

• which runbook was selected
• which evidence items were confirmed
• which conclusion fired
• which next actions were recommended

Connect To Real Systems

After the zero-config demo, you can connect the MCP server to your own observability and storage systems.

Build the server:

pnpm build

Create a config file:

cp agent-debugger.config.example.yaml agent-debugger.config.yaml

Example:

adapters:
  langfuse:
    base_url: https://cloud.langfuse.com
    secret_key: ${LANGFUSE_SECRET_KEY}
    public_key: ${LANGFUSE_PUBLIC_KEY}
  db:
    type: postgres
    connection_string: ${DATABASE_URL}
    allowed_tables: [orders, tasks]
  redis:
    url: ${REDIS_URL}
    key_prefix_allowlist: ["idempotency:", "task:idempotent:", "order:view:", "task:view:"]

runbooks:
  - ./runbooks/request_not_effective.yaml

Add the MCP server to your AI client:

{
  "mcpServers": {
    "agent-debugger": {
      "command": "node",
      "args": ["/path/to/agent-debugger/dist/mcp/server.js"],
      "env": {
        "LANGFUSE_SECRET_KEY": "sk-...",
        "LANGFUSE_PUBLIC_KEY": "pk-...",
        "DATABASE_URL": "postgresql://...",
        "REDIS_URL": "redis://..."
      }
    }
  }
}

Then provide a concrete incident:

Investigate order_id=order_123. Actual: order was created but no task was generated. Expected: a task row should exist.

What This Repo Is Not

• It is not the original internal production system.
• It is not a generic autonomous bug-fixing platform.
• It does not ship the private DAG orchestration, permission system, or internal repair workflows from the original environment.
• It does not grant unlimited automatic repair authority.

Safety Boundaries

• All adapters in this MVP are read-only.
• SQL queries are guarded against write operations.
• DB access is limited by a table allowlist.
• Redis access is limited by a key-prefix allowlist.
• Langfuse span fields are filtered by allowlist before being turned into evidence.

Built-In Runbooks

| Runbook | Scenario | |---------|---------| | request_not_effective | A request succeeded but the expected side effect did not happen | | cache_stale | Cached state appears inconsistent with persistence | | state_abnormal | Persisted business state itself looks incorrect |

Current built-in context coverage is intentionally narrow:

• request_not_effective: request_id, order_id
• cache_stale: order_id, task_id
• state_abnormal: order_id, task_id

If you want broader locator support such as trace_id or user_id, add a custom runbook through runbooks: in the config file.

Custom runbooks are supported through runbooks: entries in the config file. Each custom runbook should include sibling .selector.json, .execution.json, and .decision.json metadata files.

Architecture

Incident Input (context_id + symptom + expected)
       ↓
[Runbook Selector]   Matches signal weights via *.selector.json
       ↓
[Executor]           Calls adapters in order defined by the runbook
       ↓
[Adapter Layer]      Langfuse / PostgreSQL / Redis -> Evidence[]
       ↓
[Decision Engine]    Maps evidence to a conclusion and next actions
       ↓
[Reporter]           Structured IncidentReport

Documentation

• Architecture Design
• Evidence Model
• Runbook Specification
• Adapter Specification
• Evaluation
• Release Checklist
• Release Announcement Draft
• v0.1.0 Release Notes Draft
• Changelog
• Security Policy

Contributing

See CONTRIBUTING.md

License

MIT