Inside the Build

Beta: Inside the Build is being tested with a small group of design partners. It is not a scoring system, an authorship detector, or a complete record of an engineer's work.

Inside the Build is a local-first MCP server for engineering take-homes. It finds the Claude Code and Codex sessions associated with one Git repository, extracts prompts, visible assistant replies, and tool names, and asks the candidate's agent to write an inspectable process brief next to the submitted code.

The final repository shows what was built. Inside the Build adds evidence about how the work developed: decisions, corrections, verification steps, and candidate-specific topics for a follow-up conversation. The report describes events; it does not independently evaluate or recommend a hiring decision.

Five-minute setup

Requirements

• macOS or Linux. Windows is not yet tested.
• Node.js 20 or newer.
• A Git repository. Plain downloaded folders are not supported unless initialized as Git.
• Work completed with Claude Code or Codex. Other agents are not supported in this beta.

Run the matching command from the take-home repository:

# Claude Code — local to the current project
claude mcp add --scope local inside-the-build -- npx -y inside-the-build@beta

# Codex
codex mcp add inside-the-build -- npx -y inside-the-build@beta

After finishing the assignment, start a fresh Claude Code or Codex session in that repository. As the first request in the new session, invoke the submit_takehome prompt or tool. The agent will be instructed to save:

<repository>-inside-the-build.md

Open that file before sharing it. Prompts can contain credentials, personal information, or other sensitive text even though tool output and file contents are excluded.

See Getting started for removal commands, troubleshooting, and the full workflow.

What the report contains

• A five-point summary of the work's overall arc.
• Candidate-specific follow-up questions for a live conversation.
• A model-written timeline based on the extracted sessions.
• Receipts that point to quoted session events.
• A diagnostic footer describing the tool versions, bytes read, and skipped sessions.

Read the synthetic example. It was written from invented fixture data and contains no candidate or employer information.

Data flow

Claude Code / Codex session files
              │
              ▼
  local project matching + extraction
              │
              ▼
 candidate's local coding agent writes Markdown
              │
              ▼
 <repository>-inside-the-build.md

Inside the Build has no application server, account system, database, upload, or runtime telemetry. It reads session files on the same machine and returns data through a local stdio MCP connection. Any later sharing of the Markdown file happens outside this project.

For the exact inclusion rules and important discovery behavior, read Data flow and privacy.

Read the limitations before using it

This beta has material limitations:

• Cross-session chronology is not guaranteed by the current renderer.
• Malformed JSONL lines can be omitted without an exact dropped-line count.
• Receipt citations are requested but are not automatically verified in production.
• Session text is untrusted input to the writing model and can contain prompt injection.
• Reports vary by model and do not prove authorship, cheating, skill, or completeness.
• There is no built-in secret redaction.

Treat every report as an inspectable draft and one input to a technical conversation. Read the complete Known limitations before a real hiring workflow.

For hiring teams

Use the report to ask better questions about a work sample: why an approach changed, how a failure was diagnosed, or what the candidate would do differently. Do not treat a missing, short, or malformed report as evidence that a candidate did no work. The project documents its data flow but does not prescribe an employer participation or consent policy.

The beta is referral-driven. Design partners can share onboarding friction and broader engineering-hiring pain points in Discord. Never post real candidate artifacts, raw sessions, credentials, or personal data in GitHub or Discord.

Project status

0.1.0-beta.1 is the first public beta. The current release deliberately prioritizes documentation, packaging, contribution infrastructure, and design-partner learning. Known correctness work is tracked in the Roadmap.

• Architecture and maintenance invariants
• Known limitations
• Security policy
• Support
• Contributing
• Governance
• Code of Conduct
• Changelog

Development

bun install --frozen-lockfile
bun test
bun run typecheck
bun run build
bun run check:package

Runtime code under src/ must work under plain Node.js. Bun is used for development and tests only. Contributions require passing checks and a Developer Certificate of Origin sign-off; see CONTRIBUTING.md.

License

Licensed under the Apache License 2.0.