Spear Street Technology operates Instinct, an AI personal assistant available by private access and led by Noah Shinn, a former research scientist at Sierra. The product connects to a user's own accounts — email among them — and acts on their behalf, placing it in the class of consumer agents described at Agentic AI rather than among assistant products confined to a chat surface.
Public information about the company is limited to coverage of its terms of service and of tester reports. Founding date, funding, headcount and headquarters are not established in the available record, and the confidence rating on this page reflects that.
Terms of service
Instinct's terms of service grant the service a perpetual and irrevocable licence to access, use, host, cache, store, reproduce, transmit, display, publish, distribute and modify user materials, including for model training, and allow it to enter binding agreements, commitments or transactions on a user's behalf (Source: techcrunch.com). The combination — an irrevocable content licence extending to training, paired with authority to bind the user contractually — is broader than the terms typically attached to assistant products that read but do not transact.
Tester objections, August 2026
Testers raised privacy and security objections between August 21 and August 24, 2026:
- Peter Yang reported on August 21 that Instinct would not delete his Gmail records on request. The team subsequently closed that gap by adding a deletion tool in settings.
- Claire Vo found the same day that Instinct summarised her inbox three hours after she disconnected its Google access, and that the bot said the emails were stored in plain text for later search.
- Alex Cohen said on August 22 that he deleted his account after testing how easily the agent could be phished from a newly created Gmail account.
Instinct's team had not responded publicly to the complaints as of August 24, 2026 (Source: techcrunch.com).
The three reports concern distinct failure modes. The retention findings bear on whether revoking an integration revokes the data already ingested; the plain-text storage claim bears on how ingested content is held; and the phishing test bears on whether an agent with account access can be induced to act by content it reads. The last is the consumer-facing form of the prompt-injection exposure treated at Prompt Injection.
Relationships
- instance-of: Agentic AI — a consumer agent acting on a user's own accounts.
- related: Sierra — Instinct is led by a former Sierra research scientist.
- related: Prompt Injection — the reported phishing test is an instance of the exposure created by giving an agent account access.
- related: Agent Autonomy Spectrum (5 Levels) — the authority to enter binding agreements places the product high on the delegation axis.
- related: AI and Privacy — the retention and plain-text-storage reports.