sync-acp-spec

name: sync-acp-spec description: Sync the ACP (Agent Client Protocol) schema implementation with the official reference repo by comparing Rust source types against our Python Pydantic models.

Sync ACP Spec

Keep src/acp/schema/ aligned with the official Agent Client Protocol reference implementation.

Steps

1. Clone the reference repo into a temporary directory:

   tmp=$(mktemp -d)
   git clone --depth 1 https://github.com/agentclientprotocol/agent-client-protocol "$tmp/acp"
   

2. Identify new commits since last sync:

   git -C "$tmp/acp" log --oneline <SPEC_SYNCED_COMMIT>..HEAD
   

   The synced commit hash is stored as SPEC_SYNCED_COMMIT in src/acp/__init__.py.

3. Read the upstream Rust source (the authoritative types):

   • $tmp/acp/src/agent.rs — agent-side types: capabilities, auth methods, session state, config options, slash commands, content blocks, session updates, MCP servers
   • $tmp/acp/src/client.rs — client-side types: client capabilities, requests, responses
   • $tmp/acp/src/error.rs — error codes and Error struct
   • $tmp/acp/src/content.rs — content block types
   • $tmp/acp/src/tool_call.rs — tool call types
   • $tmp/acp/src/plan.rs — plan entry types
   • $tmp/acp/src/rpc.rs — JSON-RPC message types, method strings
   • $tmp/acp/src/ext.rs — extension notifications
   • $tmp/acp/src/version.rs — protocol version constant
   • $tmp/acp/schema/schema.json and schema.unstable.json — JSON Schema (useful for cross-checking)

4. Compare with our Python implementation (mapping table):

   Upstream Rust file	Our Python module
   agent.rs (capabilities)	schema/capabilities.py
   agent.rs (auth, common types)	schema/common.py
   agent.rs (session updates)	schema/session_updates.py
   agent.rs (session state)	schema/session_state.py
   agent.rs (slash commands)	schema/slash_commands.py
   agent.rs (MCP servers)	schema/mcp.py
   agent.rs (responses)	schema/agent_responses.py
   agent.rs (requests to client)	schema/agent_requests.py
   client.rs (requests)	schema/client_requests.py
   client.rs (responses)	schema/client_responses.py
   client.rs (capabilities)	schema/capabilities.py
   content.rs	schema/content_blocks.py
   tool_call.rs	schema/tool_call.py
   plan.rs	schema/agent_plan.py
   rpc.rs	schema/messages.py
   ext.rs	schema/notifications.py
   error.rs	schema/common.py (Error), exceptions.py (RequestError)
   version.rs	schema/__init__.py (PROTOCOL_VERSION)

5. Apply updates to our code:

   • Add new Pydantic model fields matching new Rust struct fields
   • Map #[cfg(feature = "unstable_*")] fields to field: Type | None = None
   • Add new types / enums / discriminated unions
   • Update Literal types for new method strings in schema/messages.py
   • Update __init__.py exports in both schema/__init__.py and acp/__init__.py
   • Preserve our camelCase alias convention (alias_generator=to_camel in base)
   • Do NOT modify protocol logic outside schema/ (connection handlers, bridge, transports) — only update those if they need to handle new schema types

6. Wire up new schema types in the protocol layer (if needed):

   • agent/connection.py — add dispatch cases for new agent methods
   • client/connection.py — add client-side methods for new requests
   • bridge/bridge.py — add bridge handler cases
   • agent/protocol.py — add methods to the Agent protocol
   • agent/implementations/testing.py — add stubs to TestAgent
   • agent/implementations/debug_server/mock_agent.py — add stubs to MockAgent

7. Wire up in the ACP server (if needed):

   • src/agentpool_server/acp_server/acp_agent.py — implement new methods, advertise new capabilities
   • src/agentpool_server/acp_server/event_converter.py — emit new session update types
   • src/agentpool_server/acp_server/session.py — store new state

8. Update the synced commit hash in src/acp/__init__.py:

   git -C "$tmp/acp" rev-parse HEAD
   

   Update the SPEC_SYNCED_COMMIT constant to the new hash.

9. Clean up:

   rm -rf "$tmp"
   

Key conventions

• Rust #[serde(rename_all = "camelCase")] → handled by our alias_generator=to_camel in Schema base
• Rust #[serde(rename = "_meta")] → handled by our convert() function (field_meta → _meta)
• Rust Option<T> → T | None = None
• Rust #[serde(default)] booleans → bool = False or bool | None = False
• Rust #[serde(tag = "type")] enums → Pydantic discriminated unions with Discriminator()
• Rust #[serde(untagged)] variants → Field(exclude=True) on the type discriminator field
• Rust Vec<T> → Sequence[T] (for inputs) or list[T]
• Rust HashMap<K, V> → dict[K, V]
• Unstable features (#[cfg(feature = "unstable_*")]) → always included, marked with **UNSTABLE** docstrings

What NOT to change

• connection.py (base JSON-RPC connection) — only if the wire protocol itself changes
• transports.py — transport layer is our own
• stdio.py — our process management layer
• client/ implementations (DefaultACPClient, HeadlessACPClient, NoOpClient) — agentpool-specific
• registry/ — our agent registry, not part of ACP spec
• task/ — our task abstraction
• tool_call_reporter.py, tool_call_state.py — our extensions
• filesystem.py — our filesystem handler implementation