Parallax for Claude Code

Parallax turns repository work into a visible, testable protocol. Before mutation, it captures ambiguity, invariants, and verification evidence. After mutation, it verifies the native tool batch, records a linked trace, and bounds retries instead of quietly weakening the gate. State is isolated by Claude session_id; Horizon plans are schema-validated and durable across long-running sessions.

Why Parallax

Related MCP server: codex-bridge

Requirements

• Claude Code >=2.1.215 <3 (tested range)

• Node.js 20 or newer

Installation

npm — recommended

Install the package globally, then register the plugin with Claude Code:

npm install --global parallax-claudecode
parallax-claudecode --scope user

Restart Claude Code, open any project, and run:

/parallax-claudecode:status

The installer is explicit by design: installing an npm package never edits Claude settings as a hidden lifecycle side effect. Available scopes:

parallax-claudecode --scope user      # all projects for your user
parallax-claudecode --scope project   # shared through .claude/settings.json
parallax-claudecode --scope local     # private to the current checkout
parallax-claudecode --dry-run         # preview Claude commands only
parallax-claudecode doctor --json     # stable machine-readable diagnostics

Doctor derives the current hook events and exact parallax_*/horizon_* MCP tool names from the installed runtime, so its inventory and count cannot drift from a packed release.

To update:

npm update --global parallax-claudecode
parallax-claudecode --scope user

Native uninstall is explicit; Parallax never edits Claude settings or deletes plugin data itself:

parallax-claudecode uninstall --scope user --keep-data
# equivalent native command:
claude plugin uninstall parallax-claudecode@parallax-local --scope user --keep-data

Omit --keep-data only when you intend Claude to remove its plugin data directory. Project .parallax/ and ~/.parallax/horizon/ stores are separate and remain yours to archive or remove.

From source

git clone https://github.com/Master0fFate/parallax-claudecode.git
cd parallax-claudecode
npm ci
npm run build
npm run install:local

For development without installation:

npm run dev

npm run dev launches claude --plugin-dir <repository> and forwards arguments after --.

Manual marketplace installation

claude plugin marketplace add /absolute/path/to/parallax-claudecode
claude plugin install parallax-claudecode@parallax-local

Validate a checkout with:

claude plugin validate --strict .claude-plugin/plugin.json
claude plugin validate --strict .claude-plugin/marketplace.json
npm run check

Use

Claude namespaces plugin skills automatically:

The plugin also supplies parallax and horizon subagents. Ask Claude to use parallax for non-trivial implementation/refactoring/debugging and horizon for a large goal requiring durable feature tracking and bounded autonomous retries.

Examples: interactive check-in, long-horizon goal, and Hyperplan.

Protocol

1. Ambiguity: classify LOW/MEDIUM/HIGH and resolve only material questions.

2. Four invariants: identify state ownership, feedback location, deletion coupling, and timing/ordering risk with concrete repository evidence.

3. Verification gate: establish the existing pattern, blast radius, trust boundary, and exact falsifying checks.

4. Execute: make coherent batches and repair failed verification without weakening checks.

5. Commit decision: choose Full Coherence, Pragmatic Partial, Hold + Clarify, or User Override.

6. Summary: report behavior, files, checks, and residual risk.

Hyperplan is optional for ordinary work and expected for meaningful integration, security, migration, architecture, or operational risk. It uses independent analysis, cross-attack, defense, and evidence-based synthesis rather than pasting critic prose into a plan.

Horizon

Horizon persists plans and runs one worker at a time. Completion requires a worker-bound schema-v2 receipt with exact pass, followed by a distinct read-only auditor verdict; prose, legacy scores, and caller-supplied evidence do not open completion. Retries are bounded. Horizon advances only while Claude Code is running and permissions are granted: it is not a background daemon and does not guarantee autonomous or perfect completion. In Claude Code 2.1.215, background subagent completion metadata is incomplete, so Horizon conservatively uses foreground child dispatch and durable stop/completion correlation.

Guarantee matrix

State and privacy

<project>/.parallax/sessions/<safe-session-id>/state.json
<project>/.parallax/traces/<safe-session-id>.json
<project>/.parallax/mutation-intents/<safe-session-id>/queue.json
<project>/.parallax/verification-ledger.jsonl
<project>/.parallax/ledger-archive/*
~/.parallax/horizon/sessions/<horizon-id>/...

Session IDs are checked at persistence boundaries; unsafe IDs receive deterministic safe paths. Writes use locks and atomic replacement. Implicit MCP session lookup succeeds only when exactly one matching session exists. Traces contain concise decisions, observations, mutations, and verification evidence—not hidden chain-of-thought.

Set PARALLAX_HORIZON_HOME to relocate durable Horizon storage. The MCP server resolves project state from explicit API options first, then Claude's CLAUDE_PROJECT_DIR, then PARALLAX_PROJECT_ROOT, avoiding dependence on the plugin-cache working directory.

Project policy

Parallax reads <project>/.parallax/config.json on each relevant hook or verification call. The effective default remains the OpenCode runtime default, strict. Existing OpenCode metadata is accepted and validated:

{
  "strictness": "standard",
  "designDocRequired": false,
  "maxRetries": 3,
  "maxRecoveryAttempts": 3,
  "minScore": 70,
  "adaptiveProtocol": true,
  "trivialPatterns": ["*.md"],
  "highRiskPatterns": ["**/auth/**"]
}

• strict blocks mutation until ambiguity, invariants, and gate evidence is complete.

• standard and relaxed match the source implementation's soft behavior: ambiguity remains mandatory, then up to three persisted mutation batches are allowed before missing invariants blocks further mutation. A multi-file batch counts once; the source currently makes no enforcement distinction between these two values.

• designDocRequired: true always requires the ordered ambiguity → invariants → gate → design chain. This is an intentional fail-closed improvement over the legacy edge case where missing invariant evidence could bypass design enforcement. Claude Code does not honor PARALLAX_FORCE for this project policy.

• maxRetries is bounded to 1–20 and maxRecoveryAttempts to 1–10. Policy changes preserve observed failures rather than resetting them.

• minScore, adaptiveProtocol, and path patterns are compatibility metadata; they are validated but do not change native Claude hook policy in this release.

Malformed recognized fields fail the mutation gate closed. Project config cannot specify arbitrary verification executables (verificationCommand and related keys are rejected), because hooks run verification automatically.

Verification detection

Detection begins at the hook working directory and searches parents. Cargo, Go, Node, Python, and .NET projects are supported. Node verification respects the project lockfile and prefers check, then available typecheck, test, lint, and build scripts. Commands use argument arrays rather than shell interpolation, including the required Windows package-manager shim. Explicit command arrays are available only to trusted programmatic callers of runVerification; repository config cannot add a command.

Package and development

npm run typecheck
npm test
npm run coverage
npm run build
npm run verify:package
npm run check
npm run release:proof
npm pack --dry-run

Published packages include compiled dist, native plugin metadata, agents, all namespaced skills, hooks, docs, examples, license, and explicit install/dev/release-proof scripts. Source, tests, coverage, .parallax/release-proof reports, local state, and secrets are rejected by package verification. npm run release:proof performs a clean check, a bounded all-scope npm audit at the explicit high threshold, strict manifest validation, real tarball inspection, and isolated packed-runtime smoke against exactly Claude Code 2.1.215. Its sanitized schema-v2 report is written under .parallax/release-proof/; every applicable check must pass for publishable: true. Authentication-dependent model turns remain visibly skipped and non-applicable when credentials are unavailable because direct packed hook/MCP tests prove the deterministic criteria. Native role frontmatter is asserted as packaged static configuration; CLI init inventories are not represented as per-agent effective runtime permissions. Coverage enforces repository-wide V8 thresholds, while the test matrix exercises tools, hooks, concurrent persistence, corrupt-state recovery, project/path handling, security boundaries, and deterministic fixtures. CI runs checks on Node 20/22 across Linux, Windows, and macOS and validates both Claude manifests.

Programmatic APIs are exported from the package root, including SessionStore, HorizonStore, detectProject, runVerification, and computeCoherenceScore.

Run parallax-claudecode doctor for redacted Markdown or parallax-claudecode doctor --json for schema-versioned JSON. It checks actual Claude/Node versions, native registration/cache freshness, manifests and entrypoints, role declarations, config, canonical storage writeability, state/ledger/archive schemas, locks/queues, and package metadata. An unhealthy result includes remediation and exits nonzero.

Documentation

• Architecture

• Migration from parallax-opencode

• Troubleshooting

• Contributing

• Security policy

Support

• Found a bug? Open a bug report.

• Have an idea? Request a feature.

• For private vulnerability reports, follow the security policy.

License

MIT © 2026 Master0fFate