PromptShark vs Sidenote

PromptShark and Sidenote are both inference engines & infra tracked by AIDiveForge. Below is a side-by-side comparison of pricing, capabilities, platforms, and ownership — sourced from each tool's live website and verified before publishing.

PromptShark

PromptShark is a local MITM proxy written in Go and C++ that sits between your agent and any OpenAI-compatible API endpoint. Every request and response pair is captured, logged, and surfaced in a real-time dashboard — no changes to your agent code, just a single base_url swap. The loop detector flags infinite tool-calling cycles automatically. The time-travel replay feature lets you re-run or edit any historical API step without firing a live request, which means no extra token spend during debugging. The self-hosted, MIT-licensed architecture means your prompts and API keys never leave your own infrastructure.

Sidenote

SideNote deploys an OS-level agent across company devices, monitoring drafts across email, chat, and documents without browser extensions or per-app plugins. When language crosses a threshold — discriminatory screening language, a pasted API key, an antitrust-adjacent phrase — a coaching prompt appears immediately, explaining the problem and suggesting a compliant rewrite. Leadership gets anonymized, aggregated heat maps and trend data; no individual message content surfaces to the dashboard. The four baseline models cover employment law, culture safety, ethics, and data handling, with specialized regulatory add-ons for industries like healthcare, securities, and government contracting. The vendor states these specialized models were developed with Big Law domain experts.

Attribute	PromptShark	Sidenote
Pricing	Free	Paid
Free trial	No	No
Open source	Yes	No
Has API	Yes	No
Self-hosted option	Yes	No
Platforms	Cross-platform (Go binary + Docker)	—
Pros	Zero-instrumentation integration via a single base_url swap, so you get full request visibility without touching your agent's codebase or adding an SDK dependency. Automatic infinite tool-calling loop detection, which means runaway agent cycles are flagged before they drain your token budget rather than after you read the invoice. Per-step token usage and USD cost tracking surfaced in real time, so you can attribute spend to specific agent decisions rather than receiving an opaque monthly total. Time-travel replay lets you re-run and edit any past API step without issuing a live request, so iterating on a prompt variant costs nothing in tokens during a debugging session. MIT-licensed and fully self-hostable via Docker, which means your prompts, responses, and API keys remain on your own infrastructure with no third-party data handling.	OS-level deployment covers every communication channel — email, chat, documents — without per-app plugins, so a credential accidentally pasted into a chat thread gets flagged the same way a drafted email does. Real-time coaching at the drafting stage, not post-send monitoring, so the employee learns why a phrase is problematic before it enters the corporate record — reducing the exposure that shows up months later in discovery. Anonymized, aggregated leadership dashboards surface organizational health trends and training gaps without exposing individual message content, so the platform gives legal and HR teams actionable intelligence without creating a surveillance optics problem. Industry-specific regulatory models — HIPAA, FCPA, ITAR, securities, antitrust — layer on top of the baseline suite, so a financial services firm and a defense contractor can deploy the same platform with different compliance profiles without custom development. Aggregated trend data — heat maps, training ROI metrics — gives leadership a way to identify which teams or managers need intervention before a complaint is filed, not after.
Cons	The proxy is scoped to OpenAI-compatible API calls; agents using Anthropic, Google, or other non-OpenAI-format endpoints get no coverage, and teams with a mixed provider setup gain only partial visibility. The docs describe no multi-user access controls or role separation, so the tool cannot be safely exposed across a development team without additional network-layer restrictions — teams beyond a single developer typically add a separate access layer or switch to a purpose-built observability platform. There is no alerting or notification system described in the repository; when a loop fires at 2 AM, the dashboard captures it, but nobody is paged — teams with production monitoring requirements move to a dedicated tracing platform such as LangSmith or Langfuse that integrates with existing alerting pipelines. With only 3 commits and 1 star at the time of curation, the project is early-stage; the community reports no track record of sustained maintenance, which is a real risk if you build a debugging workflow around it and a breaking API change in the upstream OpenAI spec goes unpatched.	The anonymized dashboard architecture that protects employee privacy also means leadership cannot pull the specific flagged message when an incident requires it. When a compliance or legal team needs to reconstruct a conversation for a regulatory inquiry, SideNote's aggregated-only data model forces them to go to the source communication platform — at which point they are running two separate investigations. OS-level agent deployment across a large enterprise requires IT coordination that browser-extension tools skip entirely. For organizations that cannot push agent installs to all endpoints — contractors, BYOD fleets, remote workers on unmanaged devices — coverage has structural gaps the product cannot close without device management infrastructure the vendor does not provide. There is no self-hosted option and no free tier, which means organizations in highly restricted data environments — certain government agencies, defense contractors operating under data residency mandates — face a structural blocker before the compliance models are even relevant. Teams in those environments typically evaluate on-premise solutions where SideNote does not compete.

Bottom line

PromptShark is free while Sidenote is paid; PromptShark is open source; only PromptShark exposes a public API. Choose based on which difference matters most for your workflow.

Frequently asked questions

What is the difference between PromptShark and Sidenote?

PromptShark is Free and open source, while Sidenote is Paid. Compare pricing, free trial, API, platforms, and pros/cons in the table above on AIDiveForge.

Is PromptShark better than Sidenote?

It depends on your workflow. Use the side-by-side attributes (pricing, open source, API, self-hosted, platforms) to decide. AIDiveForge does not rank a universal winner — we publish verified facts so you can choose.