Testing Webhook Signature Verification
A signature is only useful if the bad branches are actually exercised.
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security
Testing the Permission Matrix
A matrix that only proves the admin can do everything has not really been tested.
Read articleWhen an Agent Removes Input Validation and Trusts Callers
Deleted guards are easy to miss in a large agent diff.
Read articleRead-Only Database Access and Safety
The desktop reads the live schema, but it cannot write.
Read articleJWS Signature Checks and Their Limits
A valid signature answers a narrow question, not the whole trust question.
Read articleRedact Before You Paste It Into the Coding Agent
The prompt is not a scratchpad. A token, an internal hostname, or customer PII you paste into the agent lives in a log you do not fully control, long after the fix ships.
Read articleThe agent cached a GET by path and handed one tenant another tenant's row
The agent memoized a slow GET endpoint keyed only on the request path, warmed it locally under one fixed test user, and stayed green. In staging, a second tenant read the first tenant's row because the cache key never included the authenticated subject.
Read articleThe agent added debug logging and wrote the Authorization header to plaintext logs
The agent traced a failing call by logging the whole header map, so the Authorization bearer token landed in plaintext logs on every retry. Local tests use a dummy token and miss it, but aggregation keeps the real credential. Debugging needs the request's shape, not its secrets.
Read articleThe agent sorted the JSON body keys to tidy it up, and the request signature stopped matching
The agent sorted the webhook body's JSON keys alphabetically after signing. Shape-only tests passed, CI went green, but production returned 401 signature_invalid: the receiver rehashed the reordered bytes and got a different digest. Order is cosmetic to a parser; bytes are everything to a signature.
Read articleThe agent fetched the access token once at boot and cached it forever, so rotation broke the app hours later
The agent fetched a client-credentials token once at startup, cached it for the process lifetime, and never modeled expiry. Stubbed tests passed, the deploy was clean, and an hour later calls returned 401 until a restart. A short-lived token was treated as a static key.
Read articleYour MCP Hub Exposes Every Tool to Every Agent. That's the Bug.
A shared MCP hub that lists all 40 tools to every connected agent is a convenience until the billing agent starts calling create_user. The fix isn't stricter prompts — it's a smaller tool list per agent, derived from the spec.
Read articleScope MCP Keys to the Human, Not to the Team
When you hand MCP gateway access to support and PMs, a team-wide key becomes the incident waiting to happen. Scope the key to the human, the role, and the three ops they actually use.
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