Summary

Fixes #4392 - When fetch() fails at the network level (timeout, connection refused, DNS failure, etc.), the error was not being caught within fetchFirecrawlContent, causing unhandled promise rejections that could crash the gateway.

Problem

When a sub-agent uses web_fetch and the underlying fetch() call fails at the network level (not an HTTP error like 404, but a TCP/connection-level failure), the promise rejection was not caught within fetchFirecrawlContent. This bubbled up as an unhandled rejection that triggered process.exit(1) in the global handler.

Solution

Wrap the fetch() and res.json() calls in fetchFirecrawlContent with try-catch blocks to:

• Catch network-level fetch failures (TypeError: fetch failed) and throw a descriptive error
• Catch invalid JSON response errors and throw a descriptive error

The descriptive errors propagate up to the tool execution wrapper in pi-tool-definition-adapter.ts which converts them to proper tool error results, preventing the gateway from crashing.

Changes

• src/agents/tools/web-fetch.ts - Wrap fetch() and res.json() with try-catch in fetchFirecrawlContent
• src/agents/tools/web-tools.fetch.test.ts - Add test cases for network-level errors and invalid JSON responses

Test plan

• Added test case for network-level fetch failure in firecrawl fallback
• Added test case for invalid JSON response from firecrawl
• Manual verification: Trigger a network timeout during web_fetch and verify error is returned as tool result instead of crashing

🤖 Generated with Claude Code