Codex Control Plane MCP

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codex_submit_task

Queue a durable Codex write operation and return an operationId for tracking. Supports chat, execution, and thread operations with retry-safe submission.

Instructions

Queue a durable Codex write operation and return operationId immediately. For project-scoped work, pass project_id from codex_list_projects.projectId; project name or project path are accepted aliases and MCP stores the canonical projectId. Always pass client_request_id and poll codex_get_operation_status.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`operation_type`	Yes
`client_request_id`	No	Stable retry idempotency key. If omitted, MCP creates a new operation and relies on prompt deduplication to prevent active duplicate turns.
`agent_id`	No	Optional orchestrator/agent id used by the central worker scheduler for per-agent limits.
`resource_keys`	No	Optional write-scope keys. Disjoint keys allow parallel workspace-write/danger-full-access turns in the same project.
`priority`	No		normal
`estimated_cost_class`	No		normal
`thread_mode`	No	Explicit thread intent. Defaults to new_thread for start_chat and continue_thread for send_message/execute_plan.
`dedup_policy`	No	Controls prompt duplicate handling without changing client_request_id idempotency.
`allow_historical_continuation`	No	Opt-in only. Allows fuzzy duplicate matching to continue a completed historical thread.
`project_id`	No	Project reference for start_chat and other project-scoped operations. Prefer the canonical projectId returned by codex_list_projects; the listed project name or full project path are also accepted and canonicalized before durable writes.
`chat_id`	No
`thread_id`	No	Required for operation_type='steer_turn'. Target thread that owns the active turn.
`source_thread_id`	No	Required for operation_type='fork_thread'. Source thread to fork from.
`expected_turn_id`	No	Required for operation_type='steer_turn'. Active turn id precondition passed to Codex app-server.
`workflow_id`	No
`message`	No	Required for all operation types except fork_thread. For fork_thread, omit it for fork-only or provide it to start the first turn in the forked thread.
`input_items`	No	Optional image inputs appended to the text message for operation types that start a new turn. Supports image URL and localImage file path items only.
`title`	No
`cwd`	No
`model`	No
`fork_config`	No
`ephemeral`	No
`output_schema`	No	Optional JSON Schema passed to app-server outputSchema for this turn final assistant message.
`collaboration_mode`	No
`approval_policy`	No		on-request
`sandbox`	No		read-only
`force`	No
`timeout_seconds`	No
`first_message_max_chars`	No

Output Schema

TableJSON Schema

Name	Required	Description	Default
`ok`	Yes
`error`	No
`agentGuidance`	No
`agentGuidanceText`	No
`recoveryAttemptState`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed8 schema fields changedv0.2.1Jun 21, 2026

addedInput schema / properties / agent_id

Added value: +{
+  "default": null,
+  "description": "Optional orchestrator/agent id used by the central worker scheduler for per-agent limits.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

addedInput schema / properties / allow_historical_continuation

Added value: +{
+  "default": false,
+  "description": "Opt-in only. Allows fuzzy duplicate matching to continue a completed historical thread.",
+  "type": "boolean"
+}

addedInput schema / properties / dedup_policy

Added value: +{
+  "default": null,
+  "description": "Controls prompt duplicate handling without changing client_request_id idempotency.",
+  "enum": [
+    "idempotency_only",
+    "active_prompt_guard",
+    "allow_parallel_with_resource_keys",
+    null
+  ],
+  "type": [
+    "string",
+    "null"
+  ]
+}

addedInput schema / properties / estimated_cost_class

Added value: +{
+  "default": "normal",
+  "enum": [
+    "light",
+    "normal",
+    "heavy"
+  ],
+  "type": "string"
+}

addedInput schema / properties / priority

Added value: +{
+  "default": "normal",
+  "enum": [
+    "low",
+    "normal",
+    "high"
+  ],
+  "type": "string"
+}

addedInput schema / properties / project_id / description

Added value: +"Project reference for start_chat and other project-scoped operations. Prefer the canonical projectId returned by codex_list_projects; the listed project name or full project path are also accepted and canonicalized before durable writes."

addedInput schema / properties / resource_keys

Added value: +{
+  "default": null,
+  "description": "Optional write-scope keys. Disjoint keys allow parallel workspace-write/danger-full-access turns in the same project.",
+  "items": {
+    "maxLength": 300,
+    "minLength": 1,
+    "type": "string"
+  },
+  "maxItems": 50,
+  "type": [
+    "array",
+    "null"
+  ]
+}

addedInput schema / properties / thread_mode

Added value: +{
+  "default": null,
+  "description": "Explicit thread intent. Defaults to new_thread for start_chat and continue_thread for send_message/execute_plan.",
+  "enum": [
+    "new_thread",
+    "continue_thread",
+    "auto",
+    null
+  ],
+  "type": [
+    "string",
+    "null"
+  ]
+}

Changed3 schema fields changedJun 19, 2026
- addedOutput schema / properties / agentGuidance
```
Added value: +{
+  "additionalProperties": true,
+  "type": "object"
+}
```
- addedOutput schema / properties / agentGuidanceText
```
Added value: +{
+  "type": "string"
+}
```
- addedOutput schema / properties / recoveryAttemptState
```
Added value: +{
+  "additionalProperties": true,
+  "type": "object"
+}
```

Changed10 schema fields changedv0.1.3Jun 18, 2026

addedInput schema / properties / ephemeral

Added value: +{
+  "default": false,
+  "type": "boolean"
+}

addedInput schema / properties / fork_config

Added value: +{
+  "additionalProperties": true,
+  "default": null,
+  "type": [
+    "object",
+    "null"
+  ]
+}

addedInput schema / properties / input_items

Added value: +{
+  "default": null,
+  "description": "Optional image inputs appended to the text message for operation types that start a new turn. Supports image URL and localImage file path items only.",
+  "items": {
+    "oneOf": [
+      {
+        "additionalProperties": false,
+        "properties": {
+          "detail": {
+            "default": "auto",
+            "enum": [
+              "auto",
+              "low",
+              "high",
+              "original",
+              null
+            ],
+            "type": [
+              "string",
+              "null"
+            ]
+          },
+          "type": {
+            "enum": [
+              "image"
+            ],
+            "type": "string"
+          },
+          "url": {
+            "maxLength": 8192,
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "required": [
+          "type",
+          "url"
+        ],
+        "type": "object"
+      },
+      {
+        "additionalProperties": false,
+        "properties": {
+          "detail": {
+            "default": "auto",
+            "enum": [
+              "auto",
+              "low",
+              "high",
+              "original",
+              null
+            ],
+            "type": [
+              "string",
+              "null"
+            ]
+          },
+          "path": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "type": {
+            "enum": [
+              "localImage"
+            ],
+            "type": "string"
+          }
+        },
+        "required": [
+          "type",
+          "path"
+        ],
+        "type": "object"
+      }
+    ]
+  },
+  "maxItems": 10,
+  "type": [
+    "array",
+    "null"
+  ]
+}

addedInput schema / properties / message / default
```
Added value: +null
```

addedInput schema / properties / message / description

Added value: +"Required for all operation types except fork_thread. For fork_thread, omit it for fork-only or provide it to start the first turn in the forked thread."

changedInput schema / properties / message / type

Previous value: -"string"New value: +[
+  "string",
+  "null"
+]

changedInput schema / properties / operation_type / enum

Previous value: -[
-  "start_chat",
-  "send_message",
-  "execute_plan",
-  "steer_turn"
-]New value: +[
+  "start_chat",
+  "send_message",
+  "execute_plan",
+  "steer_turn",
+  "fork_thread"
+]

addedInput schema / properties / output_schema

Added value: +{
+  "additionalProperties": true,
+  "default": null,
+  "description": "Optional JSON Schema passed to app-server outputSchema for this turn final assistant message.",
+  "type": [
+    "object",
+    "null"
+  ]
+}

addedInput schema / properties / source_thread_id

Added value: +{
+  "default": null,
+  "description": "Required for operation_type='fork_thread'. Source thread to fork from.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

changedInput schema / required

Previous value: -[
-  "operation_type",
-  "message"
-]New value: +[
+  "operation_type"
+]

First observedv0.1.2Jun 18, 2026

TDQS

A3.6/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description must disclose behavioral traits. It states the operation is durable and returns immediately, and mentions idempotency via client_request_id. It does not discuss potential side effects, rate limits, or failure behavior, which is a gap.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three sentences, efficiently front-loading the core action and key usage notes without unnecessary verbosity.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool has 29 parameters and many siblings, the description is too brief. It does not explain how to choose operation types, the meaning of many parameters, or the overall workflow, leaving much to the schema and agent's interpretation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 45%, so many parameters are already documented. The description adds value by highlighting client_request_id and project_id importance, but does not elaborate on most other parameters beyond what the schema provides.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool queues a durable write operation and returns an operationId. It mentions the return behavior and project-scoped work, but does not clearly differentiate from sibling tools like codex_start_chat or codex_send_message, which may be specific operation types.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives explicit guidance: pass project_id for project-scoped work, always provide client_request_id, and poll codex_get_operation_status. However, it does not mention when not to use this tool or list alternatives for specific use cases.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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