Borrowing it
Nothing to install: this file belongs to managedcode/dotPilot. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/managedcode/dotPilot/main/.codex/skills/dotnet-microsoft-agent-framework/references/official-docs/tutorials/agents/third-party-chat-history-storage.mdgit clone --depth 1 https://github.com/managedcode/dotPilotWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/managedcode/dotpilot/third-party-chat-history-storage)<a href="https://agentmods.dev/agents/managedcode/dotpilot/third-party-chat-history-storage"><img src="https://agentmods.dev/badge/agents/managedcode/dotpilot/third-party-chat-history-storage/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/managedcode/dotpilot/third-party-chat-history-storage"><img src="https://agentmods.dev/badge/agents/managedcode/dotpilot/third-party-chat-history-storage.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00016 | $0.04040 |
| Opus 5.5 | $0.00006 | $0.01616 |
| Sonnet 5.5 | $0.00003 | $0.00808 |
| Haiku 4.5 | $0.00002 | $0.00404 |
Grade A, and why
third-party-chat-history-storage scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
100% identical to third-party-chat-history-storage — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 464 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Storing Chat History in 3rd Party Storage
::: zone pivot="programming-language-csharp"
This tutorial shows how to store agent chat history in external storage by implementing a custom ChatMessageStore and using it with a ChatClientAgent.
By default, when using ChatClientAgent, chat history is stored either in memory in the AgentThread object or the underlying inference service, if the service supports it.
Where services do not require chat history to be stored in the service, it is possible to provide a custom store for persisting chat history instead of relying on the default in-memory behavior.
Prerequisites
For prerequisites, see the Create and run a simple agent step in this tutorial.
Install NuGet packages
To use Microsoft Agent Framework with Azure OpenAI, you need to install the following NuGet packages:
dotnet add package Azure.AI.OpenAI --prerelease
dotnet add package Azure.Identity
dotnet add package Microsoft.Agents.AI.OpenAI --prerelease
In addition, you'll use the in-memory vector store to store chat messages.
dotnet add package Microsoft.SemanticKernel.Connectors.InMemory --prerelease
Create a custom ChatMessage Store
To create a custom ChatMessageStore, you need to implement the abstract ChatMessageStore class and provide implementations for the required methods.
Message storage and retrieval methods
The most important methods to implement are:
InvokingAsync- called at the start of agent invocation to retrieve messages from the store that should be provided as context.InvokedAsync- called at the end of agent invocation to add new messages to the store.
InvokingAsync should return the messages in ascending chronological order (oldest first). All messages returned by it will be used by the ChatClientAgent when making calls to the underlying xref:Microsoft.Extensions.AI.IChatClient. It's therefore important that this method considers the limits of the underlying model, and only returns as many messages as can be handled by the model.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 464 lines · 16 tokens per session scan A 4d3ac7c10a78
third-party-chat-history-storage is an agent published in the GitHub repository managedcode/dotPilot (25 stars, last pushed 6mo ago), licensed MIT. It adds 16 tokens to every session and 4,040 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to third-party-chat-history-storage, differing in 0 lines, and is treated as a copy.
Other agents, from other repositories
Scribe
Maintains session logs, records decisions, and preserves project memory for the Squad team.
notary-archivist
An event record keeper that maintains the official story history, often called canon. It is used only by the CC template; the NeonRP engine handles this work in other modes.
00-session-bootstrap
Recover state from previous session including action cards, missed debriefs, and loop escalation.
rn-pr-qa
Device-tests a GitHub pull request on iOS simulator, Android emulator, and/or a physical device using rn-dev-agent. Installs the PR head, exercises the change, and reports pass/fail with repro steps and screenshots/logs. PARENT-SESSION-ONLY: requires MCP tools (cdp, device, rnsession) — do NOT spawn via Task tool, run…
design-builder
Use this agent for building production-ready prototypes and implementations from design specs — assembling components into full pages, wiring up interactions, integrating with APIs, setting up project scaffolding, and bridging the gap between design decisions and working software. Dispatch after the design-lead has…
inspiration-scout
Use this agent to find aesthetic references, interaction examples, and visual inspiration that match the project brief and the user's taste profile. Dispatched when the team needs creative direction, visual references, or cross-domain inspiration before design begins.