Pi headless RPC JSONL over stdin/stdout, strict LF framing, --mode json event streaming, and Node SDK alternatives (AgentSession). Use when integrating pi --mode rpc, pi --mode json, writing a client that speaks the protocol, reading JSON event streams, or choosing RPC vs in-process SDK. Use for "pi rpc client", "JSONL framing", "readline rpc", "--mode json", "json events", "embed pi without subprocess", "createAgentSession", "AgentSessionRuntime", "ModelRegistry", "embed pi", "SDK factory", even if the user only pasted JSON lines.
Pi headless RPC JSONL over stdin/stdout, strict LF framing, --mode json event streaming, and Node SDK alternatives (AgentSession). Use when integrating pi --mode rpc, pi --mode json, writing a client that speaks the protocol, reading JSON event streams, or choosing RPC vs in-process SDK. Use for "pi rpc client", "JSONL framing", "readline rpc", "--mode json", "json events", "embed pi without subprocess", "createAgentSession", "AgentSessionRuntime", "ModelRegistry", "embed pi", "SDK factory", even if the user only pasted JSON lines.
compatibility
stdio JSONL client or TypeScript SDK embedding; read pi-mono/packages/coding-agent/docs/rpc.md for framing and AgentSession guidance.
Pi RPC and SDK integration
Grounding
pi-mono/packages/coding-agent/docs/rpc.md — Framing section (LF-only record delimiter; readline incompatibility with U+2028/U+2029).
pi-mono/packages/coding-agent/docs/sdk.md — programmatic session patterns plus createAgentSession, AgentSession, createAgentSessionRuntime, ModelRegistry.create(), AuthStorage.create(), and SessionManager.inMemory().
pi-mono/packages/coding-agent/src/modes/rpc/rpc-client.ts — reference TypeScript client mentioned from rpc.md intro when applicable.
pi-mono/packages/coding-agent/src/core/agent-session.ts — API surface for in-process embedding (per rpc.md note to TypeScript users).
Invariants
Framing rules are normative text in pi-mono/packages/coding-agent/docs/rpc.md; quote or paraphrase strictly from that file when advising client implementers.
Skill commands and prompt templates are expanded for RPC prompts per rpc.mdInput expansion bullet under prompt command.
--mode json is read-only observation (stdout events); --mode rpc is bidirectional control (stdin commands + stdout responses). Different use cases, same framing caveats for U+2028/U+2029.
For TypeScript/Node embedding, createAgentSession() is the primary factory; it requires sessionManager, authStorage, and modelRegistry. For advanced multi-session hosting, use createAgentSessionRuntime() which returns AgentSessionRuntime with lower-level access to agent, sessionManager, settingsManager, modelRegistry, extensions, bashExecutor, resourceLoader — pi-mono/packages/coding-agent/docs/sdk.md.
Workflows
Choose integration: If user is on Node/TS, point to rpc.md recommendation to prefer AgentSession vs subprocess; cite the file’s opening Note for Node.js/TypeScript users.
Debug framing: Re-read Framing section; do not suggest generic line readers as compliant.
JSON event stream: For read-only observation of agent activity, point to json.md (--mode json); for bidirectional control, point to rpc.md (--mode rpc).
In-process embedding: For TypeScript/Node users who don't need subprocess isolation, prefer createAgentSession() over --mode rpc. Import from @mariozechner/pi-coding-agent. See pi-mono/packages/coding-agent/docs/sdk.md and pi-mono/packages/coding-agent/examples/sdk/.
Anti-patterns
Do not describe delimiter behavior contradicting rpc.md (only \n as record delimiter; optional \r strip on input).
