agentbridge

agentbridge is a general-purpose agent adapter library. It bridges any agent that speaks the CliAdapter trait or the agentbridge JSON subprocess protocol into the shadi_mas coordination runtime so they can exchange context, delegate tasks, and coordinate autonomously toward a shared goal.

Today's built-in adapters target CLI coding tools (Claude Code, GitHub Copilot, OpenAI Codex, Cursor Agent) since interconnecting coding assistants was the motivating use case this was first built for, and they remain the flagship example below — but nothing in CliAdapter or the coordination runtime is specific to coding tools.

How it fits into SHADI

CLI tools          agentbridge adapters       shadi_mas engine
──────────────     ─────────────────────     ─────────────────────────────
Claude Code    ──► ProfileAdapter      ──►
Copilot CLI    ──► (profiles/*.json)   ──►
Codex CLI      ──►                     ──►   MasRuntime<DevelopmentEngine>
Cursor Agent   ──►                     ──►
any CLI        ──► GenericStdioAdapter ──►
                        │                         │
                        │  ContextPacket           │  A2A / SLIM / DIR
                        │  (handoff / relay)       │  (transport / discovery)

Core types

CliAdapter (trait)

The central abstraction. A new coding CLI is a JSON profile under profiles/ (ProfileAdapter). Implement this trait only for a protocol that is not argv-driven (for example GenericStdioAdapter).

pub trait CliAdapter: Send + Sync {
    fn agent_id(&self) -> &AgentId;
    fn snapshot_context(&self) -> Result<ContextPacket, CliAdapterError>;
    fn inject_context(&self, ctx: &ContextPacket) -> Result<(), CliAdapterError>;
    fn execute_prompt(&self, prompt: &str) -> Result<String, CliAdapterError>;
}

ContextPacket

A portable, serializable snapshot of a coding session: conversation history, code files, git diff, and generated artifacts. Used for context handoff between tools and for persistence across sessions.

pub struct ContextPacket {
    pub id: String,                        // UUID v4
    pub source_agent: String,
    pub created_at: String,                // unix timestamp
    pub conversation: Vec<ConversationMessage>,
    pub code_context: CodeContext,         // files, git diff, active file
    pub artifacts: Vec<ArtifactPayload>,   // generated code, patches
}

Serializes to/from JSON:

let pkt = ContextPacket::new("claude-code");
let bytes = pkt.to_bytes()?;
let restored = ContextPacket::from_bytes(&bytes)?;

CliToolAdapter<A> (wrapper)

Bridges any CliAdapter into shadi_mas::ToolAdapter so it can participate directly in MasRuntime<DevelopmentEngine> coordination rounds.

let inner = Arc::new(MyAdapter::new());
let tool_adapter = CliToolAdapter::new(inner);
// tool_adapter now implements shadi_mas::ToolAdapter

Subprocess protocol (GenericStdioAdapter)

GenericStdioAdapter spawns a subprocess and communicates via newline-delimited JSON on stdin/stdout. Any process that speaks this protocol becomes a agentbridge participant with no code changes:

Requests (agentbridge → subprocess stdin):

{"cmd":"snapshot"}
{"cmd":"inject","context":{...}}
{"cmd":"execute","prompt":"write a parser for JSON"}

Responses (subprocess stdout → agentbridge):

{"ok":true,"data":{...}}
{"ok":false,"error":"subprocess error message"}

Spawn an adapter:

let adapter = GenericStdioAdapter::spawn(
    "my-tool",
    "my-cli",
    &["--agentbridge-mode"],
)?;

Implementing a custom adapter

use agentbridge::{CliAdapter, CliAdapterError, ContextPacket};
use shadi_mas::AgentId;

struct MyCliAdapter { id: AgentId }

impl CliAdapter for MyCliAdapter {
    fn agent_id(&self) -> &AgentId { &self.id }

    fn snapshot_context(&self) -> Result<ContextPacket, CliAdapterError> {
        // Read conversation history from the tool's state file / API
        let mut pkt = ContextPacket::new(self.id.0.clone());
        pkt.conversation.push(ConversationMessage {
            role: "assistant".to_string(),
            content: "...".to_string(),
        });
        Ok(pkt)
    }

    fn inject_context(&self, ctx: &ContextPacket) -> Result<(), CliAdapterError> {
        // Write ctx into the tool's context file or API
        Ok(())
    }

    fn execute_prompt(&self, prompt: &str) -> Result<String, CliAdapterError> {
        // Call the tool's API or subprocess with the prompt
        Ok("generated code".to_string())
    }
}

Crate features

This crate ships with zero optional features. All heavy infrastructure (shadi_mas coordination, A2A, SLIM) is brought in at the agentbridge_cli binary level so the library stays lightweight.