feat(pi): add plan mode

[BillLeoutsakosvl346]

Summary

• add a BYOK-only Plan mode that explores a disposable GitHub checkout in the existing Pi sandbox
• remove the authenticated remote before Pi starts and provide no commit, push, PR, review, or GitHub-write finalization
• reuse existing skills, memory, streaming, redaction, cancellation, and optional sandbox search extension
• expose only the inputs and outputs needed for planning

Validation

• PI executor and block/model/key-condition suites: 25 files, 464 passed, 1 skipped
• Sim type-check
• repository format and lint checks
• check:import-specifiers
• check:boundaries
• check:audits (22 audits)

Stack

This PR is intentionally based on refactor/pi-mode-folders (PR #6362). After #6362 merges, this branch will be rebased onto current staging, the PR will be retargeted to staging, and the full validation and bot-review cycle will be repeated.

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Project	Deployment	Actions	Updated (UTC)
docs	Ready	Preview	Aug 9, 2026 1:47am

[cursor]

PR Summary

Medium Risk
Introduces a new sandbox execution path with GitHub clone credentials and BYOK model keys in the remote environment; mitigations (remote removal, redaction, no finalize) are explicit but the surface area is security-sensitive.

Overview
Adds a Plan mode (cloud_plan) to the Pi Coding Agent: explore a GitHub repo in the existing E2B sandbox and return an implementation plan without commit, push, PR, or other GitHub writes.

The block UI exposes Plan alongside other modes, limits visible inputs to repo/task/model/BYOK/search/skills/memory, and hides PR/diff/branch outputs. Plan is treated like Create PR and Update PR for API keys (always BYOK in the sandbox) and extends copilot credential validation accordingly.

Execution clones the selected base branch, removes origin so the agent cannot push, runs Pi with planning guidance and optional sandbox search, and uses finalizePhases: 0 so sandbox timeouts do not reserve commit/push time. Event filtering and agent_end handling now carry final assistant text so Plan can replace streamed progress with the authoritative Markdown plan when streaming.

^{Reviewed by Cursor Bugbot for commit 43c1b99. Bugbot is set up for automated code reviews on this repo. Configure here.}

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[BillLeoutsakosvl346]

@greptile

[BillLeoutsakosvl346]

@cursor review

[greptile-apps]

Greptile Summary

This PR adds a BYOK-only Plan mode that runs Pi against a disposable GitHub checkout and returns a planning document without a GitHub write/finalization phase.

• Adds Plan-mode block inputs, output visibility, model-key handling, routing, and tests.
• Introduces an ephemeral sandbox backend that clones the selected branch, removes the authenticated remote, runs Pi, and redacts streamed output.
• Extends event normalization to expose the canonical final assistant response.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

Important Files Changed

Filename	Overview
apps/sim/executor/handlers/pi/cloud/plan/backend.ts	Implements the disposable Plan-mode clone, credential scoping, Pi execution, event handling, redaction, cancellation, and cleanup flow.
apps/sim/executor/handlers/pi/pi-handler.ts	Routes cloud_plan executions, supplies contextual inputs, emits only the canonical final plan in streaming mode, and omits change-oriented outputs.
apps/sim/blocks/blocks/pi.ts	Exposes Plan mode with its required sandbox inputs, BYOK behavior, contextual options, and Plan-appropriate outputs.
apps/sim/executor/handlers/pi/core/events.ts	Extracts text blocks from the final assistant message into a canonical final event.
apps/sim/providers/pi-providers.ts	Classifies Plan alongside other sandbox modes that require user-provided model credentials.

Sequence Diagram

sequenceDiagram
  participant Workflow
  participant Handler as Pi Handler
  participant Sandbox
  participant GitHub
  participant Pi

  Workflow->>Handler: Execute cloud_plan
  Handler->>Handler: Resolve BYOK key, skills, memory
  Handler->>Sandbox: Create disposable sandbox
  Sandbox->>GitHub: Clone selected/default branch
  Sandbox->>Sandbox: Detach checkout and remove origin
  Handler->>Sandbox: Write scrubbed prompt
  Sandbox->>Pi: Run with model/search credentials
  Pi-->>Handler: Progress and final events
  Handler-->>Workflow: Final Markdown plan and usage
  Sandbox-->>Handler: Dispose sandbox

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_{Reviews (5): Last reviewed commit: "fix(pi): stream only final plan content" | Re-trigger Greptile}

[BillLeoutsakosvl346]

@greptile

[BillLeoutsakosvl346]

@cursor review

[cursor]

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit 07949ce. Configure here.}

[BillLeoutsakosvl346]

@greptile

[BillLeoutsakosvl346]

@cursor review

[BillLeoutsakosvl346]

@greptile

[BillLeoutsakosvl346]

@cursor review

[cursor]

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit 2b653a6. Configure here.}

[BillLeoutsakosvl346]

Demo:

Screen.Recording.2026-08-08.at.6.59.17.PM.mp4