Context Loader

Context Loader renders deterministic, bounded context for one local Git working tree. The default CLI output remains Markdown; a stable JSON interface is also available for machine callers. The tool reads repository state and a fixed set of root files without fetching, executing repository code, network access, or writes to the target repository. Runtime code uses only the Python standard library.

Open-source quick start

Context Loader is a local CLI that exports repository context deterministically for coding-agent workflows, rendering stable Markdown or JSON output.

uv tool install codex-project-context-loader

pip install codex-project-context-loader

codex-project-context --repo /path/to/repo

codex-project-context --repo /path/to/repo --format json

Install

Public stable release on PyPI: 0.1.5.

Install via uv:

uv tool install codex-project-context-loader

Install via pip:

pip install codex-project-context-loader

For development or source-based installs tracking current repository (0.1.6):

uv tool install git+https://github.com/xuanheng-tech/context-loader.git

The repository also retains ./codex-project-context as a direct development entry point.

Platform and Runtime Requirements

• Python: Python 3.12 (>=3.12,<3.13). Runtime code uses only the Python standard library with zero runtime dependencies.
• Git: Requires standard git CLI installed and available in PATH.
• Operating System: POSIX / Linux environment. Windows is currently not supported.

Usage

codex-project-context --version
codex-project-context --repo /home/user/projects/example
codex-project-context --repo /home/user/projects/example --format markdown
codex-project-context --repo /home/user/projects/example --format json
codex-project-context --repo /home/user/projects/example \
  --focus "Authentication and session management" \
  --path auth/session.py

--format defaults to markdown. In Markdown mode, --repo retains the 0.1.1 contract: it must be the absolute, canonical root of a non-bare Git working tree. In JSON mode, an absolute existing directory inside the working tree is accepted; symlinks are normalized and the discovered root is reported as canonical_root. Relative paths, non-Git directories, regular files, and bare repositories are rejected in both modes.

--focus and --path are optional, bounded selection signals for the root AGENTS.md. --path must be repository-relative. The collector does not retain either input in output or audit data. Calls that omit both options remain valid and use the conservative fallback described below.

Markdown Output

Successful repository collection uses schema context-loader/v0.1 and emits these sections in order:

1. Git State, including bounded working-tree changes
2. Development Instructions
3. Project Overview
4. Declared Commands
5. Project Entry Files
6. Recent Commits
7. Directory Tree

The output has no generated timestamp, AI summary, architecture inference, or diff body.

JSON Output

--format json writes exactly one compact UTF-8 JSON document plus one trailing newline to stdout. Keys are serialized in sorted order with ensure_ascii=False. The declared contract is:

{
  "schema_version": 1,
  "tool": {
    "name": "context-loader",
    "version": "0.1.6"
  },
  "repository": {
    "requested_path": "/canonical/requested/path",
    "canonical_root": "/canonical/worktree/root"
  },
  "sources": [
    {
      "ordinal": 0,
      "kind": "agents",
      "scope": "repository",
      "path": "/canonical/worktree/root/AGENTS.md",
      "content_sha256": "sha256-hex",
      "content": "actual selected source text",
      "selection": {
        "source": "AGENTS.md",
        "selected_sections": [],
        "indexed_only_sections": [],
        "chars_selected": 0,
        "chars_omitted": 0,
        "truncated": false,
        "parse_fallback": false,
        "source_scan_truncated": false,
        "index_truncated": false
      }
    }
  ],
  "context": "the same assembled Markdown context",
  "context_sha256": "sha256-hex",
  "warnings": []
}

context_sha256 hashes the UTF-8 bytes of context; each content_sha256 does the same for that source's content. sources contains only file bodies that actually enter the final context, in assembly order, after the existing newline normalization and truncation rules. scope distinguishes repository from global; version 0.1.6's fixed root-file selection currently emits only repository sources and does not add any global-file discovery.

The optional selection object is present only on a rendered AGENTS.md source. Its section entries contain heading, heading level, and fixed selection reasons; it never contains the original focus or target path. Existing source fields and schema version 1 remain unchanged.

The JSON schema version and package version are independent: schema_version is currently the integer 1, while tool.version is 0.1.6. Callers must depend only on fields declared above. The document contains no generated time or random identifier, so unchanged input produces identical JSON bytes. On failure, stdout remains empty and stderr contains only a short diagnostic.

Supported Root Files

Only these exact files directly under the Git root are eligible:

• Development instructions: AGENTS.md
• Project overview: README.md
• Entry files, in fixed order: pyproject.toml, justfile or Justfile, package.json, Makefile, Cargo.toml, and go.mod

Lowercase justfile takes precedence over Justfile. Nested files, lockfiles, CI configuration, .env, and glob-discovered files are not read.

The root AGENTS.md is split at Markdown headings outside fenced code blocks. The output always starts with complete early sections fitting a 4-KiB head, then adds complete relevant sections in source order using exact normalized focus/path tokens and their parent context. Remaining headings appear in an explicit index whose body text is not loaded. With no selection signals, only the small head and index are emitted. Unsafe heading parsing falls back to a bounded head and an explicit manual-recovery notice.

Limits

• Final stdout: 98,304 bytes
• AGENTS.md: 256-KiB bounded source scan; selected source plus selection audit remains at most 16 KiB, including a 4-KiB maximum small head
• README.md: 16 KiB
• Each entry file: 8 KiB
• All entry-file bodies: 24 KiB
• Declared commands: 8 KiB
• Directory tree: 12 KiB, 300 entries, and depth 2
• Working-tree changes: 100 paths and 4 KiB
• Recent commits: 8

Truncation occurs only at complete UTF-8 and line boundaries and is marked explicitly.

Git State Semantics

Git state is derived only from the working tree and local refs. The command does not fetch or query the remote.

• An unborn working tree reports its symbolic branch name, such as Branch: main, and HEAD: unborn.
• A detached HEAD reports Branch: detached and the resolved commit object ID.
• Upstream is the current branch's configured tracking target. Without one, Upstream: not configured is used.
• A configured target such as origin/main may be shown before its commit is resolvable locally; this is normal after cloning an empty remote.
• Ahead / behind: not available means the commit relationship cannot currently be computed. Counts are reported only when the configured upstream commit is available locally.

Exit Codes

• 0: context or version output completed successfully
• 1: required Git collection or an internal operation failed
• 2: command arguments or the repository path do not satisfy the contract

On nonzero exit, stdout is empty and a bounded diagnostic is written to stderr without a traceback or candidate-file content.

Not Included

Version 0.1.6 does not provide AI summaries, project-type detection, nested AGENTS.md handling, Memory retrieval, semantic ranking, ignore-rule parsing, plugins, profiles, caches, databases, network services, MCP, daemons, GUIs, CI/CD, telemetry, or automatic updates.

Development

Run the complete local check:

just check

Version maintenance

The versions in pyproject.toml and context_loader/__init__.py, the matching CHANGELOG.md section, and required tests must change in the same release-preparation batch. CHANGELOG.md is the authoritative version-change record. Merging to master is not a release; formal publication still requires a separately created and pushed tag.