PR #68043: fix(gateway): preserve non-text MCP content blocks in HTTP gateway tool-call results

• Repository: openclaw/openclaw
• Author: hclsys
• State: open | merged: False
• Link: https://github.com/openclaw/openclaw/pull/68043

Description (problem / solution / changelog)

Summary

Fixes #68037 — the HTTP MCP gateway was dropping every non-text field from tools/call results, breaking browser.screenshot and every other tool that returns an image/audio/resource block.

Root cause

normalizeToolCallContent in src/gateway/mcp-http.handlers.ts mapped every returned content block to {type: block.type ?? "text", text: block.text ?? …}:

```ts return content.map((block: { type?: string; text?: string }) => ({ type: (block.type ?? "text") as "text", text: block.text ?? (typeof block === "string" ? block : JSON.stringify(block)), })); ```

Image/audio/resource blocks have no text field, so they came out as {type: "image", text: undefined} and lost data, mimeType, uri, name, resource, annotations, etc. Downstream Zod validation against the MCP content-block schema then failed with "expected string, received undefined" on data/mimeType.

Fix

Pass typed blocks through unmodified; only synthesize a text block when the entry is a primitive string or an object without a recognized type field. Widen the return type from McpTextContent[] to an open McpContentBlock union so the pass-through survives TypeScript's inference.

```ts return content.map((block) => { if (block && typeof block === "object" && typeof (block as { type?: unknown }).type === "string") { return block as McpContentBlock; } return { type: "text", text: typeof block === "string" ? block : JSON.stringify(block), }; }); ```

This is the fix the reporter proposed (pass-through for valid typed blocks, fallback for everything else). If stricter validation is preferred later, the union can be narrowed to an explicit discriminated schema.

Test plan

• Added six unit tests in `src/gateway/mcp-http.test.ts` covering:
  • image block pass-through with `data` + `mimeType` preserved
  • `resource_link` pass-through with `uri` + `name` preserved
  • audio block pass-through with `data` + `mimeType` preserved
  • existing text blocks untouched
  • untyped entries (primitive string, plain object) wrapped into text
  • fallback when `result.content` is absent entirely
• `npx tsc --noEmit` — 247 baseline on `main`, 247 on branch (no new errors).
• `pnpm exec oxlint` on touched files — 0 warnings, 0 errors.
• Existing `mcp-http.test.ts` integration cases untouched.

Local full vitest is blocked by pre-existing `test/non-isolated-runner.ts` drift (reproduces on `main`) — CI will exercise the new tests normally.

Security / behavior notes

• The fix trusts any block with a string `type` field. That matches what the MCP protocol-level schema validates client-side anyway: bad payloads fail Zod at the client with a cleaner error than today's silent field-drop.
• No existing text-block behavior changes — strings and untyped plain objects still get wrapped, and a non-array `result` still collapses to a single text block.

Changed files

• src/gateway/mcp-http.handlers.ts (modified, +15/-9)
• src/gateway/mcp-http.test.ts (modified, +59/-0)

PR #68046: fix: pass through image/audio/resource content blocks in MCP HTTP gateway

• Repository: openclaw/openclaw
• Author: nightq
• State: open | merged: False
• Link: https://github.com/openclaw/openclaw/pull/68046

Description (problem / solution / changelog)

Summary

Fixes the HTTP MCP gateway stripping image, audio, and resource fields from tool results.

Root Cause

The normalizeToolCallContent function was mapping all content blocks to only {type, text}, discarding other fields like data, mimeType, resource, uri, etc. This caused downstream Zod validation to fail for any tool returning non-text content.

Fix

• Pass through valid content blocks directly to preserve all fields
• Only apply fallback transformation for strings or malformed blocks
• Updated type definition to include all MCP content block types

Test Plan

• Added comprehensive test coverage for all content block types (text, image, audio, resource, resource_link)
• All 9 new tests pass
• Manually verified that image blocks now retain data and mimeType fields

Closes openclaw#68037

Changed files

• src/gateway/mcp-http.handlers.test.ts (added, +130/-0)
• src/gateway/mcp-http.handlers.ts (modified, +22/-9)