fix(mcp-http): ensure MCP tool schemas always include properties field by Chevron7Locked · Pull Request #69956 · openclaw/openclaw

Chevron7Locked · 2026-04-22T03:02:49Z

Summary

Problem: MCP servers can emit no-arg tools with inputSchema: {"type":"object"} and no properties key. OpenAI and OpenRouter reject this as invalid JSON Schema (object schema missing properties), returning a 400 on every request that includes the offending tool — causing the entire model call to fail and fall through to the next fallback.
Why it matters: One bad tool poisons the entire tool list for the turn. The user sees silent fallback to weaker models with no indication why. Hard to debug because the error is at the API level, not visible in normal logs.
What changed: Moved if (!raw.properties) raw.properties = {} outside the raw.type !== "object" condition in buildMcpToolSchema. Now properties: {} is always added to any object-typed schema that lacks it, regardless of whether type needed correction.
What did NOT change: Behavior for schemas that already have properties, or schemas with anyOf/oneOf that go through flattenUnionSchema.

Root cause

// Before — only added properties when type was wrong:
if (raw.type !== "object") {
  raw.type = "object";
  if (!raw.properties) raw.properties = {};  // never reached for {"type":"object"} no-properties
}

// After — always ensures properties is present:
if (raw.type !== "object") {
  raw.type = "object";
}
if (!raw.properties) raw.properties = {};

Reproduces with

mcpproxy-go v0.23.2, which emits {"type":"object"} for no-argument tools (e.g. list_registries). Affects any strict OpenAI-compatible provider.

Change Type

Bug fix

Scope

Gateway / orchestration

…ried on each turn When runWithModelFallback falls back to a secondary provider it writes providerOverride/modelOverride/modelOverrideSource:"auto" to the session. On subsequent turns createModelSelectionState read this stored override and passed the fallback provider directly to runWithModelFallback, so the configured primary was never retried — the session was permanently pinned to the fallback even after the primary recovered. Fix: at model-selection ingress, when the direct session override has modelOverrideSource "auto" (set by a previous automatic fallback, not a user /model command), clear the override and retry the configured primary. If the primary is still down runWithModelFallback will fall back and re-set the auto override for that turn. Once the primary recovers the override stays clear. User-selected overrides (modelOverrideSource "user" or legacy undefined+model) are preserved unchanged. Covered by four new unit tests in model-selection.test.ts: - auto-failover override cleared and primary retried - user-selected override preserved - legacy override without source field preserved - parent-session auto-override applied to child (not cleared by child logic)

…verride clearing Three corrections to the auto-failover self-healing introduced in the prior commit: 1. Reset in-memory provider/model to configured primary after clearing auto override. get-reply-directives.ts preloads provider/model from the stored override before calling createModelSelectionState, so clearing only session state still ran the current turn on the fallback. Now provider/model are reset to defaultProvider/ defaultModel so this turn retries the primary immediately, not on the next turn. 2. Remove resetModelOverride = true from the auto-heal path. That flag triggers a "Model override not allowed for this agent" system event in applyInlineDirectiveOverrides, which is incorrect: the override was valid and set by the fallback loop — it just expired once the primary recovered. Auto-heal is not an allowlist violation. 3. Add a test case that verifies the in-memory reset when the caller pre-loads the fallback provider/model (simulating the get-reply-directives.ts preload path). Known limitation (noted in comment): channel model overrides (channels.modelByChannel) are skipped on the recovery turn because hasSessionModelOverride was true when they were evaluated at preload time. They resume on the following turn once session state is clear. Fixing this cleanly requires changes to the get-reply-directives preload flow and is out of scope for this PR.

MCP servers sometimes emit no-arg tools with inputSchema {"type":"object"} and no "properties" key. OpenAI and OpenRouter reject this as an invalid JSON Schema — the error is "object schema missing properties" and manifests as a 400 on every request that includes the offending tool, causing the entire model call to fail and fall through to the next fallback. The fix: move the `if (!raw.properties) raw.properties = {}` guard outside the `raw.type !== "object"` condition so it applies to schemas that already have the correct type but are missing the required properties key. Before: only added properties:{} when type was wrong After: always ensures properties:{} is present on any object-typed schema Reproduces with mcpproxy-go v0.23.2 which emits {"type":"object"} for no-argument tools like list_registries. Affects any strict OpenAI-compatible provider (OpenRouter, direct OpenAI API).

greptile-apps · 2026-04-22T03:04:50Z

Greptile Summary

This PR bundles two independent fixes: (1) the titled MCP schema fix in mcp-http.schema.ts — moving properties: {} initialization outside the type-correction guard so {"type":"object"} schemas without properties pass OpenAI/OpenRouter validation — and (2) an auto-failover self-healing feature in model-selection.ts that clears auto-sourced session overrides on the next turn so the session retries the primary model instead of permanently using the fallback. Both changes are logically correct and well-tested; the only nit is a duplicated comment in the test file.

Confidence Score: 5/5

Safe to merge — both fixes are correct, tested, and non-breaking

The MCP schema fix is a minimal, targeted one-liner with no risk of regression. The model-selection auto-healing logic is more substantial but includes thorough tests covering all branch conditions (user override, legacy override, parent-inherited override). All remaining findings are P2 style issues.

No files require special attention

Prompt To Fix All With AI

This is a comment left during a code review.
Path: src/auto-reply/reply/model-selection.test.ts
Line: 571-572

Comment:
**Duplicate comment**

The same comment is copy-pasted on consecutive lines.

```suggestion
    // Provider/model should revert to the configured primary, not the fallback.
```

How can I resolve this? If you propose a fix, please make it concise.

_{Reviews (1): Last reviewed commit: "fix(mcp-http): ensure MCP tool schemas a..." | Re-trigger Greptile}

greptile-apps · 2026-04-22T03:04:55Z

+    // Provider/model should revert to the configured primary, not the fallback.
+    // Provider/model should revert to the configured primary, not the fallback.


Duplicate comment

The same comment is copy-pasted on consecutive lines.

Suggested change

// Provider/model should revert to the configured primary, not the fallback.

// Provider/model should revert to the configured primary, not the fallback.

// Provider/model should revert to the configured primary, not the fallback.

Prompt To Fix With AI

This is a comment left during a code review. Path: src/auto-reply/reply/model-selection.test.ts Line: 571-572 Comment: **Duplicate comment** The same comment is copy-pasted on consecutive lines. ```suggestion // Provider/model should revert to the configured primary, not the fallback. ``` How can I resolve this? If you propose a fix, please make it concise.

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chatgpt-codex-connector · 2026-04-22T03:07:34Z

+  if (isAutoSessionOverride && sessionEntry && sessionStore && sessionKey && !resetModelOverride) {
+    const { updated } = applyModelOverrideToSessionEntry({


Respect heartbeat override before auto-clearing model fallback

This branch runs even when hasResolvedHeartbeatModelOverride is true, so heartbeat turns that intentionally selected heartbeat.model can still enter auto-heal, clear the session override, and then force provider/model back to defaultProvider/defaultModel later in the block. In that scenario the heartbeat no longer uses the configured heartbeat model and mutates session state unexpectedly; this regresses the existing skipStoredOverride contract for heartbeat runs. Add a !skipStoredOverride guard (or otherwise preserve the current provider/model) before applying this auto-clear path.

Useful? React with 👍 / 👎.

prtags · 2026-04-23T18:49:38Z

Related work from PRtags group unique-heron-2zsc

Title: Open PR duplicate: MCP schema properties + auto-reset override self-heal composite

Number	Title
#58299	fix: normalize MCP tool schemas missing properties field for OpenAI Responses API
#60176	fix(tools): normalize truly empty MCP tool schemas for OpenAI
#69419	session: clear auto-sourced model/auth overrides on /new and /reset
#69956*	fix(mcp-http): ensure MCP tool schemas always include properties field

* This PR

steipete · 2026-04-23T20:02:49Z

Codex maintainer rewrite landed as #70763.

I kept the minimal MCP schema fix from this PR: loopback MCP object schemas now always include properties, including no-argument tools with { type: "object" }. The two auto-failover commits in this branch were already on main through #69365, so I left them out of the replacement.

While verifying this, I also chased the live Docker failure path: Codex was cancelling MCP tool calls when the generated loopback server inherited local approval prompts. #70763 marks only the generated OpenClaw loopback MCP server with Codex's per-server default_tools_approval_mode = "approve", pins the Docker smoke to Codex CLI 0.124.0, keeps the Docker Codex default on codex-cli/gpt-5.5, and adds a live Docker schema probe.

Verified with focused tests, pnpm check:changed, and Docker live Codex e2e using staged .codex/auth.json, codex-cli 0.124.0, codex-cli/gpt-5.5, live tools/list, direct cron, and model-driven cron tool call.

Thanks for spotting the MCP schema issue and for the original fix direction.

steipete · 2026-04-23T20:02:50Z

Closing in favor of the narrower maintainer rewrite in #70763. Thanks again for the original MCP schema fix direction.

Chevron7Locked added 3 commits April 20, 2026 09:43

openclaw-barnacle Bot added gateway Gateway runtime size: S labels Apr 22, 2026

greptile-apps Bot reviewed Apr 22, 2026

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chatgpt-codex-connector Bot reviewed Apr 22, 2026

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This was referenced Apr 23, 2026

fix: normalize MCP tool schemas missing properties field for OpenAI Responses API #58299

Merged

fix(tools): normalize truly empty MCP tool schemas for OpenAI #60176

Merged

session: clear auto-sourced model/auth overrides on /new and /reset #69419

Merged

steipete mentioned this pull request Apr 23, 2026

fix(gateway): normalize MCP schemas for Codex loopback #70763

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steipete closed this Apr 23, 2026

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fix(mcp-http): ensure MCP tool schemas always include properties field#69956

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		// Provider/model should revert to the configured primary, not the fallback.
		// Provider/model should revert to the configured primary, not the fallback.

		if (isAutoSessionOverride && sessionEntry && sessionStore && sessionKey && !resetModelOverride) {
		const { updated } = applyModelOverrideToSessionEntry({

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Chevron7Locked commented Apr 22, 2026

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