@jordyvd/pi-openai-compaction

A distributable Pi extension package that replays OpenAI native standalone compaction windows without patching Pi core.

This package preserves the raw compacted window returned by OpenAI's compact endpoint, stores it in Pi compaction entry details, and rewrites later supported OpenAI Responses requests to:

• fresh current prompt envelope
• stored opaque compacted window
• live post-compaction tail

Supported scope

This package is intentionally narrow.

• Providers: openai, openai-codex
• APIs: openai-responses, openai-codex-responses
• Failure mode: fail open back to normal Pi behavior
• Persistence model: store the raw compacted window in CompactionEntry.details

How it works

The extension uses two hooks:

1. session_before_compact
   • serialize the current Pi session into an OpenAI Responses-compatible compact request
   • call the compact endpoint
   • persist the returned compacted window in the compaction entry details
2. before_provider_request
   • intercept the next supported Responses request
   • replace Pi's summary-oriented replay with native replay

Install

From a checkout of this repo:

git clone https://github.com/jordyvandomselaar/pi-codex-compaction.git
cd pi-codex-compaction
pi install .

Try without installing from the repo root:

pi -e .

After installation, run:

/reload

Configuration

Settings resolve in this order, with later layers overriding earlier ones:

1. package-local settings.json
2. global ~/.pi/agent/settings.json under openaiNativeCompaction
3. project <cwd>/.pi/settings.json under openaiNativeCompaction
4. environment variables with the PI_OPENAI_NATIVE_COMPACTION_ prefix

Default package settings:

{
  "enabled": true,
  "debug": false,
  "logProviderPayloads": false,
  "logCompactResponses": false,
  "redactSensitiveData": true,
  "artifactRoot": "~/.pi/agent/artifacts/openai-native-compaction",
  "supportedProviders": ["openai", "openai-codex"],
  "supportedApis": ["openai-responses", "openai-codex-responses"],
  "notifyOnLoad": false
}

Useful global override example:

{
  "openaiNativeCompaction": {
    "enabled": true,
    "debug": true,
    "logProviderPayloads": true,
    "logCompactResponses": true,
    "redactSensitiveData": true
  }
}

Available environment overrides:

• PI_OPENAI_NATIVE_COMPACTION_ENABLED
• PI_OPENAI_NATIVE_COMPACTION_DEBUG
• PI_OPENAI_NATIVE_COMPACTION_LOG_PROVIDER_PAYLOADS
• PI_OPENAI_NATIVE_COMPACTION_LOG_COMPACT_RESPONSES
• PI_OPENAI_NATIVE_COMPACTION_REDACT_SENSITIVE_DATA
• PI_OPENAI_NATIVE_COMPACTION_ARTIFACT_ROOT
• PI_OPENAI_NATIVE_COMPACTION_SUPPORTED_PROVIDERS
• PI_OPENAI_NATIVE_COMPACTION_SUPPORTED_APIS
• PI_OPENAI_NATIVE_COMPACTION_NOTIFY_ON_LOAD

Debug artifacts

Artifacts are written per session under:

~/.pi/agent/artifacts/openai-native-compaction/sessions/<session-id>/

Subdirectories:

• provider-requests/
• compact-responses/
• compaction-events/
• lifecycle/

Recommended troubleshooting flow:

1. enable debug: true
2. enable logProviderPayloads: true
3. keep redactSensitiveData: true
4. /reload
5. run /compact and then send a follow-up message
6. inspect the newest artifact in the session directory

Package structure

package-root/
├── index.ts                    # package entrypoint declared in package.json
├── settings.json               # package-local defaults
├── src/
│   ├── extension-runtime.ts    # hook registration and top-level wiring
│   ├── settings.ts             # layered settings loader + env overrides
│   ├── debug.ts                # artifact writing + redaction helpers
│   ├── runtime.ts              # provider/api/model/baseUrl/apiKey resolution
│   ├── supported-environment.ts
│   ├── types.ts                # settings + persisted native-compaction types
│   ├── details-store.ts        # latest-valid native compaction lookup helpers
│   ├── serializer.ts           # compaction input serialization helpers
│   ├── compact-client.ts       # compact endpoint client
│   └── payload-rewrite.ts      # native replay rewrite logic
├── src/unit.test.ts
├── src/validation.test.ts
└── test/pi-smoke.test.ts

Tests

git clone https://github.com/jordyvandomselaar/pi-codex-compaction.git
cd pi-codex-compaction
bun test
bun test --coverage --coverage-reporter=text --coverage-reporter=lcov
bun test ./test/pi-smoke.test.ts