fix(responses): preserve author, recipient, encrypted_content in multi-agent collab_tool_call items

[Shaik-Sirajuddin]

Fixes #4608

Problem

ResponsesMessage had no Author or Recipient struct fields, and ResponsesMessageContentBlock had no EncryptedContent field. Go's JSON decoder silently drops unknown fields on decode, so these values were stripped before bifrost re-serialized the request to the upstream provider.

This breaks Codex 0.141.0+ multi_agent_v2 subagent spawning entirely. OpenAI requires all three fields on collab_tool_call input items and on reasoning content blocks during history replay.

Changes

core/schemas/responses.go

// ResponsesMessage — two new fields:
Author    json.RawMessage `json:"author,omitempty"`
Recipient json.RawMessage `json:"recipient,omitempty"`

// ResponsesMessageContentBlock — one new field:
EncryptedContent *string `json:"encrypted_content,omitempty"`

json.RawMessage is used for author/recipient so bifrost passes the objects through verbatim without assuming OpenAI's multi-agent schema shape, which may evolve.

How to verify

# Requires Codex 0.141.0+ and bifrost proxying an OpenAI Responses API endpoint
codex exec \
  -c model_provider=bifrost \
  -c model=gpt-5.5 \
  --enable multi_agent_v2 \
  --dangerously-bypass-approvals-and-sandbox \
  "write hello to hello.txt then spawn a subagent to verify it exists"

Before fix: 400 Missing required parameter: 'input[N].author' on the second request.
After fix: Session completes — subagent spawns, verifies file, reports back. All /v1/responses return 200.

Test plan

• Existing unit/integration tests pass
• Manual end-to-end: Codex multi_agent_v2 subagent spawn through bifrost returns 200 on all turns
• Verify author, recipient, encrypted_content are present in the request bifrost forwards upstream (can check with send_back_raw_request: true on a deliberate error)

[CLAassistant]

All committers have signed the CLA.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro Plus

Run ID: 43fcdc29-a4a8-4ce7-8b74-97d098361f33

📥 Commits

Reviewing files that changed from the base of the PR and between 1cdd311 and 47030bb.

📒 Files selected for processing (1)

• core/schemas/responses.go

---

📝 Walkthrough

Summary by CodeRabbit

• New Features
  • Enhanced multi-agent collaboration by introducing author and recipient tracking for collaborative tool calls, improving visibility across agent interactions.
  • Added encrypted content support for reasoning blocks, strengthening security and ensuring accurate playback during conversation history review.

Walkthrough

Three fields are added to core/schemas/responses.go: Author and Recipient (as json.RawMessage) on ResponsesMessage for multi-agent collab_tool_call items, and EncryptedContent (as *string) on ResponsesMessageContentBlock for reasoning history replay. The encoding/json import is added to support the raw message types.

Changes

Responses Schema Field Additions

Layer / File(s)	Summary
Add Author, Recipient, EncryptedContent to response schemas core/schemas/responses.go	encoding/json import added; ResponsesMessage extended with Author and Recipient as json.RawMessage (preserving multi-agent collab tool call objects verbatim); ResponsesMessageContentBlock extended with EncryptedContent *string for reasoning content blocks during history replay.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Possibly related PRs

• maximhq/bifrost#3528: Also modifies ResponsesMessage in core/schemas/responses.go by adding new JSON-serialized struct fields, directly overlapping with this PR's schema touchpoints.
• maximhq/bifrost#3584: Uses ResponsesMessage and content-block schemas in mux conversion logic, including handling of reasoning/encrypted content fields added here.

Suggested reviewers

• danpiths
• akshaydeo

Poem

🐇 Three fields were missing, the schema incomplete,
author and recipient lost on the street.
encrypted_content vanished in the round-trip air,
A 400 from OpenAI said "fields aren't there!"
I hopped in, added them — RawMessage and string,
Now Codex subagents can do their thing! 🎉

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main change: adding three fields to response schemas to preserve multi-agent collaboration data during JSON serialization.
Description check	✅ Passed	The description provides clear problem statement, specific code changes, and detailed verification steps, though test plan items are marked as incomplete rather than confirmed.
Linked Issues check	✅ Passed	The code changes directly address all requirements from issue #4608: adding Author and Recipient fields to ResponsesMessage and EncryptedContent to ResponsesMessageContentBlock using appropriate types.
Out of Scope Changes check	✅ Passed	All changes are scoped to the three fields required by issue #4608 with no unrelated modifications to other functionality or files.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 golangci-lint (2.12.2)

level=error msg="[linters_context] typechecking error: pattern ./...: directory prefix . does not contain main module or its selected dependencies"

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[greptile-apps]

Confidence Score: 3/5

The schema change is correct and addresses the described failure, but the streaming accumulator's deep-copy helpers are not updated, leaving the new fields absent from the accumulated response consumed by post-hook plugins.

The fix correctly targets the JSON decode/re-encode path for request input items. However, deepCopyResponsesMessage and deepCopyResponsesMessageContentBlock in framework/streaming/responses.go — which are actively called for every streamed output item — do not copy Author, Recipient, or EncryptedContent. Any plugin that inspects or re-serializes the accumulated streaming response will see these fields silently absent, and as the multi-agent protocol evolves to return collab_tool_call output items, the same stripping problem reappears on the response side.

framework/streaming/responses.go — both deep-copy helpers need to mirror the new fields added to the schema structs.

Important Files Changed

Filename	Overview
core/schemas/responses.go	Adds Author/Recipient (json.RawMessage) to ResponsesMessage and EncryptedContent (*string) to ResponsesMessageContentBlock to preserve multi-agent fields through JSON round-trips; schema change is correct but streaming deep-copy helpers are not updated.
framework/streaming/responses.go	deepCopyResponsesMessage does not copy the new Author/Recipient fields, and deepCopyResponsesMessageContentBlock does not copy EncryptedContent; both are actively called in the streaming accumulator, so these fields are silently dropped in the accumulated response passed to post-hook plugins.

Sequence Diagram

%%{init: {'theme': 'neutral'}}%%
sequenceDiagram
    participant Codex
    participant Bifrost
    participant OpenAI

    Codex->>Bifrost: POST /v1/responses (input includes collab_tool_call with author/recipient)
    Note over Bifrost: Unmarshal into ResponsesMessage<br/>author+recipient decoded as json.RawMessage ✅
    Bifrost->>OpenAI: Forward request (author+recipient preserved) ✅
    OpenAI-->>Bifrost: Stream response (output_item.added)
    Note over Bifrost: deepCopyResponsesMessage called<br/>Author/Recipient NOT copied ❌
    Note over Bifrost: Accumulated response passed to plugins<br/>author+recipient missing in plugin view
    Bifrost-->>Codex: Stream proxied (original bytes intact ✅)
    Codex->>Bifrost: Next turn: POST /v1/responses (history with prior items)
    Note over Bifrost: Schema fix ensures fields survive decode/re-encode ✅

Loading

%%{init: {'theme': 'base', 'themeVariables': {"darkMode": true, "background": "#0d1117", "primaryColor": "#21262d", "primaryTextColor": "#e6edf3", "primaryBorderColor": "#8b949e", "lineColor": "#8b949e", "textColor": "#e6edf3", "edgeLabelBackground": "#161b22", "actorBkg": "#21262d", "actorBorder": "#8b949e", "actorTextColor": "#e6edf3", "actorLineColor": "#8b949e", "signalColor": "#8b949e", "signalTextColor": "#e6edf3", "noteBkgColor": "#373320", "noteBorderColor": "#d4a72c", "noteTextColor": "#f0e6c0", "labelBoxBkgColor": "#21262d", "labelBoxBorderColor": "#8b949e", "labelTextColor": "#e6edf3", "loopTextColor": "#e6edf3", "activationBkgColor": "#30363d", "activationBorderColor": "#8b949e"}}}%%
sequenceDiagram
    participant Codex
    participant Bifrost
    participant OpenAI

    Codex->>Bifrost: POST /v1/responses (input includes collab_tool_call with author/recipient)
    Note over Bifrost: Unmarshal into ResponsesMessage<br/>author+recipient decoded as json.RawMessage ✅
    Bifrost->>OpenAI: Forward request (author+recipient preserved) ✅
    OpenAI-->>Bifrost: Stream response (output_item.added)
    Note over Bifrost: deepCopyResponsesMessage called<br/>Author/Recipient NOT copied ❌
    Note over Bifrost: Accumulated response passed to plugins<br/>author+recipient missing in plugin view
    Bifrost-->>Codex: Stream proxied (original bytes intact ✅)
    Codex->>Bifrost: Next turn: POST /v1/responses (history with prior items)
    Note over Bifrost: Schema fix ensures fields survive decode/re-encode ✅

Loading

_{Reviews (1): Last reviewed commit: "fix(responses): preserve author, recipie..." | Re-trigger Greptile}