feat: add Pi.dev Agent SDK support as a first-class AI assistant provider by Copilot · Pull Request #1 · dammyammy/Archon

Copilot · 2026-04-11T16:30:39Z

Summary

Adds Pi.dev as a third AI assistant provider alongside Claude and Codex. Pi is a multi-provider coding agent SDK that supports Anthropic, OpenAI, Google, Mistral, OpenRouter, and many other LLM providers through a single unified interface.

Changes

New client: `packages/core/src/clients/pi.ts`

PiClient implementing IAssistantClient using @mariozechner/pi-coding-agent SDK
Bridges Pi's event subscription model to Archon's AsyncGenerator<MessageChunk> interface via a queue-based adapter
Supports streaming text deltas, thinking tokens, tool calls, and tool results
Model selection via provider/model-id format (e.g. anthropic/claude-opus-4-5, openai/gpt-4o)
Abort signal support via session.abort()
Session resume not supported (Pi uses in-memory sessions; logs a warning and starts fresh)

Provider type propagation

All 'claude' | 'codex' type unions updated to 'claude' | 'codex' | 'pi' across:

packages/core/src/config/config-types.ts — PiAssistantDefaults, MergedConfig, SafeConfig, GlobalConfig, RepoConfig
packages/core/src/config/config-loader.ts — defaults, merge, env override, toSafeConfig, updateGlobalConfig
packages/workflows/src/deps.ts — AssistantClientFactory, WorkflowConfig
packages/workflows/src/schemas/dag-node.ts — provider enum
packages/workflows/src/schemas/workflow.ts — provider enum
packages/workflows/src/model-validation.ts — isModelCompatible accepts 'pi' (all models valid)
packages/workflows/src/executor.ts — resolvedProvider type
packages/workflows/src/loader.ts — provider acceptance check
packages/workflows/src/dag-executor.ts — all provider type annotations, pi option building branch
packages/workflows/src/validator.ts — pi warnings for Claude-only features (hooks, MCP, skills, tool restrictions)
packages/server/src/routes/schemas/config.schemas.ts — API schema enums
packages/server/src/routes/api.ts — config update handler
packages/cli/src/commands/setup.ts — defaultAssistant type annotation
packages/core/src/clients/factory.ts and index.ts — factory and export

Documentation

README.md — new "Using Pi.dev as Your AI Backend" section with setup instructions, supported providers table, and workflow YAML examples

Notes for reviewers

bun.lock not updated: bun install must be run to pull @mariozechner/pi-coding-agent@^0.66.1 and update the lockfile. This is expected — the sandboxed environment does not have bun available.
api.generated.d.ts not updated: This file is auto-generated from the OpenAPI spec. Run bun run dev:server then bun --filter @archon/web generate:types to regenerate after this PR is merged.
Pi-specific limitations: Claude-only features (hooks, MCP servers per-node, skills, structured output, env injection) are silently ignored for provider: pi. Validator warnings were added for hooks, MCP, skills, and tool restrictions.
CodeQL: 0 security alerts found.

…ider Agent-Logs-Url: https://github.com/dammyammy/Archon/sessions/10aedf44-074e-4f29-8d9d-87b146927cdd Co-authored-by: dammyammy <3688497+dammyammy@users.noreply.github.com>

Agent-Logs-Url: https://github.com/dammyammy/Archon/sessions/10aedf44-074e-4f29-8d9d-87b146927cdd Co-authored-by: dammyammy <3688497+dammyammy@users.noreply.github.com>

Copilot

Pull request overview

Adds Pi.dev as a third AI assistant provider in Archon, integrating the @mariozechner/pi-coding-agent SDK into the existing assistant client + workflow execution architecture.

Changes:

Introduces a new PiClient implementing IAssistantClient, bridging Pi’s event stream to Archon’s AsyncGenerator<MessageChunk> streaming interface.
Propagates provider: 'pi' support across config types/loaders, workflow schemas/parsing, execution, validation, and server API schemas/handlers.
Updates README documentation to describe Pi setup and usage.

Reviewed changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
README.md	Documents Pi as an AI backend (setup, env vars, model format, workflow examples).
packages/workflows/src/validator.ts	Adds Pi-specific warnings for Claude-only features (MCP, skills, hooks, tool restrictions).
packages/workflows/src/schemas/workflow.ts	Extends workflow-level provider enum to include `pi`.
packages/workflows/src/schemas/dag-node.ts	Extends node-level provider enum to include `pi`.
packages/workflows/src/model-validation.ts	Allows all models when provider is `pi`.
packages/workflows/src/loader.ts	Accepts `pi` as a valid provider during workflow parsing.
packages/workflows/src/executor.ts	Expands resolved provider typing to include `pi` (with comment about inference).
packages/workflows/src/deps.ts	Extends workflow config + assistant factory types to include `pi` and Pi assistant defaults.
packages/workflows/src/dag-executor.ts	Adds Pi option-building branch for node execution (model-only support).
packages/server/src/routes/schemas/config.schemas.ts	Extends API config schemas to include `pi` assistant config.
packages/server/src/routes/api.ts	Allows updating Pi assistant config via the config PATCH route.
packages/core/src/services/title-generator.ts	Updates docs to include `pi` as a possible assistant type.
packages/core/src/config/config-types.ts	Adds `PiAssistantDefaults` and extends assistant/provider unions to include `pi`.
packages/core/src/config/config-loader.ts	Adds Pi defaults, merge behavior, env overrides, and safe config mapping.
packages/core/src/clients/pi.ts	New Pi client implementation using Pi agent SDK + queue-based stream adapter.
packages/core/src/clients/index.ts	Re-exports `PiClient`.
packages/core/src/clients/factory.ts	Adds factory support for `type === 'pi'`.
packages/core/package.json	Adds `@mariozechner/pi-coding-agent` dependency.
packages/cli/src/commands/setup.ts	Expands default assistant typing to include `pi`.

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Copilot · 2026-04-11T21:24:37Z

+
+  - id: implement
+    depends_on: [plan]
+    provider: anthropic   # per-node override (uses node-level provider)


The workflow example uses provider: anthropic, but workflow/node provider only accepts the assistant providers (claude, codex, pi). For Pi, keep provider: pi and set the Anthropic model via model: anthropic/<model-id>; if you intend to use the native Claude client, use provider: claude instead.

Suggested change

provider: anthropic # per-node override (uses node-level provider)

provider: pi # per-node override (uses Pi with the node-level model)

Copilot · 2026-04-11T21:24:37Z

+      // Warn if using MCP with Codex or Pi
+      if (provider === 'codex' || provider === 'pi') {
        issues.push({
          level: 'warning',
          nodeId: node.id,


Validator behavior changed to warn for provider === 'pi', but the existing validator test suite only covers the Codex warnings. Add equivalent test cases asserting warnings for Pi (MCP, skills, hooks, tool restrictions) so this new provider path stays covered.

Copilot · 2026-04-11T21:24:37Z

  // When workflow sets a model but not a provider, infer provider from the model.
  // e.g. model: sonnet → provider: claude, even if config.assistant is codex.
-  let resolvedProvider: 'claude' | 'codex';
+  // Pi workflows should always set provider: pi explicitly (pi models cannot be auto-inferred).
+  let resolvedProvider: 'claude' | 'codex' | 'pi';
  let providerSource: string;


The comment here notes that Pi “cannot be auto-inferred”, but the provider-resolution logic later in this function still infers a non-Claude workflow.model to codex when workflow.provider is omitted. That means a defaultAssistant: pi setup can silently switch to Codex just by setting model at the workflow level. Consider adding explicit handling for config.assistant === 'pi' (or provider/model-id model strings) so Pi remains the resolved provider unless the workflow explicitly opts out.

Copilot · 2026-04-11T21:24:37Z


  // Determine default assistant
-  let defaultAssistant: 'claude' | 'codex' = 'claude';
+  let defaultAssistant: 'claude' | 'codex' | 'pi' = 'claude';


defaultAssistant is now typed to include 'pi', but this setup flow only reasons about Claude/Codex (hasClaude/hasCodex) and never offers/configures Pi. Either add Pi detection + selection + config generation, or keep the type here limited to assistants that archon setup can actually configure so the generated config doesn’t imply unsupported values.

Suggested change

let defaultAssistant: 'claude' | 'codex' | 'pi' = 'claude';

let defaultAssistant: 'claude' | 'codex' = 'claude';

Copilot AI and others added 2 commits April 11, 2026 16:24

fix: clean up pi client log event names to follow project conventions

0d41f71

Agent-Logs-Url: https://github.com/dammyammy/Archon/sessions/10aedf44-074e-4f29-8d9d-87b146927cdd Co-authored-by: dammyammy <3688497+dammyammy@users.noreply.github.com>

Copilot AI assigned Copilot and dammyammy Apr 11, 2026

Copilot created this pull request from a session on behalf of dammyammy April 11, 2026 16:32 View session

Copilot AI requested a review from dammyammy April 11, 2026 16:32

Copilot finished work on behalf of dammyammy April 11, 2026 16:32

dammyammy approved these changes Apr 11, 2026

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dammyammy marked this pull request as ready for review April 11, 2026 21:20

Copilot AI review requested due to automatic review settings April 11, 2026 21:20

dammyammy merged commit f258a4a into dev Apr 11, 2026

Copilot started reviewing on behalf of dammyammy April 11, 2026 21:20 View session

Copilot AI reviewed Apr 11, 2026

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feat: add Pi.dev Agent SDK support as a first-class AI assistant provider#1

feat: add Pi.dev Agent SDK support as a first-class AI assistant provider#1
dammyammy merged 2 commits intodevfrom
copilot/add-pi-dev-agent-sdk-support

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	provider: anthropic # per-node override (uses node-level provider)
	provider: pi # per-node override (uses Pi with the node-level model)

	let defaultAssistant: 'claude' \| 'codex' \| 'pi' = 'claude';
	let defaultAssistant: 'claude' \| 'codex' = 'claude';

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Copilot AI commented Apr 11, 2026

Summary

Changes

New client: packages/core/src/clients/pi.ts

Provider type propagation

Documentation

Notes for reviewers

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New client: `packages/core/src/clients/pi.ts`