Evidence Sources

This guide is derived from reverse-engineering Amp Code (Sourcegraph's AI coding agent). This document catalogs all evidence sources used.

Primary Sources

1. Production Bundle Analysis (Highest Confidence)

Version Date Size Notes
v0.0.1769212917 Jan 2026 7.2MB / 353K lines Latest analyzed version
v0.0.1766534507 Dec 2025 7.2MB / 374K lines Previous version
v0.0.1766390481 Dec 2025 7.2MB / 373K lines Earlier December

What we extracted:

  • Complete tool definitions and schemas
  • System prompts (verbatim)
  • All constants and magic numbers
  • State machine logic
  • Mode configurations
  • Subagent prompts and configurations

2. Rosetta Stone (Original TypeScript)

Version Size Files
v0.0.1744408301-dev 289KB bundle 71 .ts files

Contains: Original TypeScript source with source maps, providing ground truth for:

  • Class names and interfaces
  • Function signatures
  • Type definitions
  • Architecture patterns

3. Changelog Analysis

Source: ampcode.com/news

Covered period: April - December 2025 (~1,980 versions)

Provided:

  • Feature evolution timeline
  • Mode introduction dates
  • Tool additions and changes
  • Breaking changes

Extraction Methodology

Deobfuscation Process

  1. Bundle extraction - Pulled from ~/.sourcegraph/ installation
  2. Deobfuscation - Restored readable variable names where possible
  3. Cross-reference - Matched patterns against Rosetta Stone
  4. Verification - Tested against live behavior

Confidence Levels

Level Meaning Examples
⭐⭐⭐⭐⭐ Verbatim from source System prompts, tool schemas
⭐⭐⭐⭐ High confidence, deobfuscated Constants, state logic
⭐⭐⭐ Inferred from patterns Some architectural decisions
⭐⭐ Educated guess Internal motivations

What We Did NOT Access

  • Private Sourcegraph documentation
  • Internal design docs
  • Backend/server code
  • Analytics or telemetry data
  • User data of any kind

All analysis was performed on the publicly distributed client bundle.

Verification Methods

1. Cross-Version Verification

Compared structures across multiple versions to confirm stability:

  • Tool names consistent across 3+ versions
  • Prompt patterns stable
  • Constants unchanged

2. Behavioral Testing

Where possible, tested against live Amp Code:

  • Tool execution patterns
  • Mode switching behavior
  • Error handling

3. Rosetta Stone Matching

Matched deobfuscated patterns against original TypeScript:

  • Class hierarchies
  • Interface shapes
  • Function signatures

Limitations

  1. Minification artifacts - Some variable names remain obfuscated
  2. Server-side logic - Cannot see backend processing
  3. Dynamic configuration - Some values may be server-controlled
  4. Version drift - Analysis reflects specific versions; newer versions may differ

Original Analysis

The excavation was performed on the npm package @sourcegraph/amp.

The analysis that produced this specification is maintained separately.

This specification is for educational purposes. All analyzed code belongs to Sourcegraph.