hermes-agent/website/docs/user-guide/features/context-references.md

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9	Context References	Context References	Inline @-syntax for attaching files, folders, git diffs, and URLs directly into your messages

Context References

Type @ followed by a reference to inject content directly into your message. Hermes expands the reference inline and appends the content under an --- Attached Context --- section.

Supported References

Syntax	Description
@file:path/to/file.py	Inject file contents
@file:path/to/file.py:10-25	Inject specific line range (1-indexed, inclusive)
@folder:path/to/dir	Inject directory tree listing with file metadata
@diff	Inject git diff (unstaged working tree changes)
@staged	Inject git diff --staged (staged changes)
@git:5	Inject last N commits with patches (max 10)
@url:https://example.com	Fetch and inject web page content

Usage Examples

Review @file:src/main.py and suggest improvements

What changed? @diff

Compare @file:old_config.yaml and @file:new_config.yaml

What's in @folder:src/components?

Summarize this article @url:https://arxiv.org/abs/2301.00001

Multiple references work in a single message:

Check @file:main.py, and also @file:test.py.

Trailing punctuation (,, ., ;, !, ?) is automatically stripped from reference values.

CLI Tab Completion

In the interactive CLI, typing @ triggers autocomplete:

• @ shows all reference types (@diff, @staged, @file:, @folder:, @git:, @url:)
• @file: and @folder: trigger filesystem path completion with file size metadata
• Bare @ followed by partial text shows matching files and folders from the current directory

Line Ranges

The @file: reference supports line ranges for precise content injection:

@file:src/main.py:42        # Single line 42
@file:src/main.py:10-25     # Lines 10 through 25 (inclusive)

Lines are 1-indexed. Invalid ranges are silently ignored (full file is returned).

Size Limits

Context references are bounded to prevent overwhelming the model's context window:

Threshold	Value	Behavior
Soft limit	25% of context length	Warning appended, expansion proceeds
Hard limit	50% of context length	Expansion refused, original message returned unchanged
Folder entries	200 files max	Excess entries replaced with - ...
Git commits	10 max	@git:N clamped to range [1, 10]

Security

Sensitive Path Blocking

These paths are always blocked from @file: references to prevent credential exposure:

• SSH keys and config: ~/.ssh/id_rsa, ~/.ssh/id_ed25519, ~/.ssh/authorized_keys, ~/.ssh/config
• Shell profiles: ~/.bashrc, ~/.zshrc, ~/.profile, ~/.bash_profile, ~/.zprofile
• Credential files: ~/.netrc, ~/.pgpass, ~/.npmrc, ~/.pypirc
• Hermes env: $HERMES_HOME/.env

These directories are fully blocked (any file inside):

• ~/.ssh/, ~/.aws/, ~/.gnupg/, ~/.kube/, $HERMES_HOME/skills/.hub/

Path Traversal Protection

All paths are resolved relative to the working directory. References that resolve outside the allowed workspace root are rejected.

Binary File Detection

Binary files are detected via MIME type and null-byte scanning. Known text extensions (.py, .md, .json, .yaml, .toml, .js, .ts, etc.) bypass MIME-based detection. Binary files are rejected with a warning.

Platform Availability

Context references are primarily a CLI feature. They work in the interactive CLI where @ triggers tab completion and references are expanded before the message is sent to the agent.

In messaging platforms (Telegram, Discord, etc.), the @ syntax is not expanded by the gateway — messages are passed through as-is. The agent itself can still reference files via the read_file, search_files, and web_extract tools.

Interaction with Context Compression

When conversation context is compressed, the expanded reference content is included in the compression summary. This means:

• Large file contents injected via @file: contribute to context usage
• If the conversation is later compressed, the file content is summarized (not preserved verbatim)
• For very large files, consider using line ranges (@file:main.py:100-200) to inject only relevant sections

Common Patterns

# Code review workflow
Review @diff and check for security issues

# Debug with context
This test is failing. Here's the test @file:tests/test_auth.py
and the implementation @file:src/auth.py:50-80

# Project exploration
What does this project do? @folder:src @file:README.md

# Research
Compare the approaches in @url:https://arxiv.org/abs/2301.00001
and @url:https://arxiv.org/abs/2301.00002

Error Handling

Invalid references produce inline warnings rather than failures:

Condition	Behavior
File not found	Warning: "file not found"
Binary file	Warning: "binary files are not supported"
Folder not found	Warning: "folder not found"
Git command fails	Warning with git stderr
URL returns no content	Warning: "no content extracted"
Sensitive path	Warning: "path is a sensitive credential file"
Path outside workspace	Warning: "path is outside the allowed workspace"