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Runtime guardrails and AI firewalls · #12 by signal score

CalypsoAI

Runtime guardrails for AI inference: inspects prompts, outputs, and agent tool calls, blocks unauthorized tool calls, and logs every enforcement decision with its reasoning. Acquired by F5 in 2025; now sold as F5 AI Guardrails.

Acquired by F5, announced 2025-09-11, closed 2025-09-26 ($145.2M, per SEC filing). Now sold as F5 AI Guardrails.

19Signal score / 100
Capital
9.1/35
Product
10/25
Standards
0/20(not yet assessed)
Momentum
0/20

Identity primitives

Agent as a first-class identityNot checked
On-behalf-of token exchangeNot checked
Cross App Access (ID-JAG)Not checked
Asynchronous human approval (CIBA)Not checked
MCP authorization conformanceNot checked
Fine-grained authorizationNot checked
Short-lived, secretless credentialsNot checked
Token vaultNot checked
Kill switchNo public claim found
Per-action audit chainNo public claim found

Company

HQ: IE
Funding: $38.2M disclosed, latest Series A-1

Sources

  1. F5 AI Guardrails (vendor, accessed 2026-09-23)
  2. F5 to acquire CalypsoAI to bring advanced AI guardrails to large enterprises (sec, accessed 2026-09-23)
  3. CalypsoAI raises $23 million for AI security tech (trade-press, accessed 2026-09-23)
  4. F5, Inc. Form 10-K for the fiscal year ended September 30, 2025 (sec, accessed 2026-09-23)

Last verified 2026-09-23.